Category Archives: History of Chemistry

Renaissance science – XLII

As with much in European thought, it was Aristotle, who first made a strong distinction between, what was considered, the two different realms of thought, theoretical thought epistêmê, most often translated as knowledge, and technê, translated as either art or craft. As already explained in an earlier post in this series, during the Middle Ages the two areas were kept well separated, with only the realm of epistêmê considered worthy of study by scholars. Technê being held to be inferior. As also explained in that earlier post the distinguishing feature of Renaissance science was the gradual dissolution of the boundary between the two areas and the melding of them into a new form of knowledge that would go on to become the empirically based science of the so-called scientific revolution. 

A second defining characteristic of the developing Renaissance science was the creation of new spaces for the conception, acquisition, and dissemination of the newly emerging forms of knowledge. We have followed the emergence of libraries outside of the monasteries, the establishment of botanical gardens as centres of learning, and cabinets of curiosity and the museums that evolved out of them, as centres for accumulating knowledge in its material forms. 

Another, space that emerged in the late Renaissance for the generation and acquisition of knowledge was the laboratory. The very etymology of the term indicates very clearly that this form of knowledge belonged to the technê side of the divide. The modern word laboratory is derived from the Latin laboratorium, which in turn comes from laboratus the past participle of laboare meaning to work. This origin is, of course, clearly reflected in the modern English verb to labour meaning to work hard using one’s hands, and all of the associated words, the nouns labour and labourer etc. It was only around 1600 that the word laboratorium came to signify a room for conducting scientific experiments, whereby the word scientific is used very loosely here. 

Of course, laboratories, to use the modern term, existed before the late sixteenth century and are mostly associated with the discipline of alchemy. Much of the Arabic Jabirian corpus, the vast convolute of ninth century alchemical manuscripts associated with the name Abū Mūsā Jābir ibn Ḥayyān is concerned with what we would term laboratory work. It would appear that medieval Islamic culture did not share the Aristotelian disdain for manual labour. However, in Europe, the practical alchemist in his workshop or laboratory actually working with chemicals was regarded as a menial hand worker. Although, it should be remembered that medieval alchemy incorporated much that we would now term applied or industrial chemistry, the manufacture of pigments or gunpowder, just to give two examples. Many alchemists considered themselves philosophical alchemists, often styling themselves philosopher or natural philosopher to avoid the stigma of being considered a menial labourer. 

The status of artisan had already been rising steadily since the expansion in European trade in the High Middle Ages and the formation of the guilds, which gave the skilled workers a raised profile. After all, they manufacture many of the goods traded. It should also be remembered that the universities were founded as guilds of learning, the word universitas meaning a society or corporation. 

So, what changed in the sixteenth century to raise the status of the laboratorium, making it, so to speak, acceptable in polite society? The biggest single change was the posthumous interest in the medical theories of Theophrastus of Hohenheim (c. 1493–1541), or as he is better known Paracelsus (c. 1493–1541), based on his medical alchemy, known as chymiatria or iatrochemistry, a process that began around 1560. 

Aureoli Theophrasti ab Hohenheim. Reproduction, 1927, of etching by A. Hirschvogel, 1538. Source: Wikimedia Commons

The new Paracelsian iatrochemistry trend did not initially enter the Renaissance university but found much favour on the courts of the European royalty and aristocracy and it was here that the new laboratoria were established by many of the same potentates, who had founded new libraries, botanical garden, and cabinets of curiosity. The Medici, Spanish and Austrian Hapsburgs, and Hohenzollerns all established laboratoria staffing them with their own Paracelsian alchemical physicians. Many of these regal loboratoria resembled the workshops of apothecaries, artisans, and instrument makers. Techné had become an integral part of the European aristocratic court. 

It was in the Holy Roman Empire that the Renaissance laboratory celebrated its greatest success. The most well documented Renaissance laboratory was that of Wolfgang II, Graf von Hohenlohe und Herr zu Langenburg (1546–1610). In 1587, having constructed a new Renaissance residence, he constructed a two-story alchemical laboratory equipped with a forge, numerous furnaces, a so-called Faule Heinz or Lazy Henry which made multiple simultaneous distillations possible, and a vast array of chemical glass ware.

Graf Wolfgang II. zu Hohenlohe-Weikersheim, Portrait by Peter Franz Tassaert in the great hall of the castle in Weikersheim Source: Wikimedia Commons

His library contained more than five hundred books, of which fifteen were about practical chemistry, for example from Georg Agricola (1494–1555), author of De re metallica, Lazarus Ecker (c. 1529–1594), a metallurgist, and books on distillation from Heironymous Brunschwig (c. 1450–c. 1512), thirty-three about alchemy including books from Pseudo-Geber (late 13th early 14th centuries), Ramon Llull (c.1232–1316), Berhard von Trevesian (14th century), and Heinrich Khunrath (c. 1560–1605), sixty-nine books by Paracelsus, and twelve about chemiatria including works by Leonhard Thurneysser (1531–1596), Alexander von Suchten (c.1520–1575) , both of them Paracelsian physicians, and Johann Isaac Hollandus (16th & 17th centuries!), a Paracelsian alchemist and author of very detailed practical chemistry books. The laboratory had a large staff of general and specialised workers but was run by a single laborant for sixteen years.

Wolfgang’s fellow alchemist and correspondent, Friedrich I, Duke of Württemberg (1557–1608) employed ten Laboranten in the year 1608 and a total of thirty-three between 1593 and 1608.

Friedrich I, Duke of Württemberg artist unknown Source: Wikimedia Commons

Friedrich had a fully equipped laboratory constructed in the old Lusthaus of a menagerie and pleasure garden. A Lusthaus was a large building erected in aristocratic parks during the Renaissance and Baroque used for fests, receptions, and social occasions.

New Lusthaus in Stuttgart (1584–1593) Engraving by Matthäus Merian 1616 Source: Wikimedia Commons

He also had laboratories in Stuttgarter Neue Spital and in the Freihof in Kirchheim unter Teckabout 25 kilometres south of Stuttgart, where he moved his court during an outbreak of the plague in 1594. Friedrich was interested in both chymiatria and the production of gold and gave a fortune out in pursuit of his alchemical aim. However, he also used his laboratories for metallurgical research.

Heinrich Khunrath (c. 1560–1605) was a Paracelsian physician, hermetic philosopher, and alchemist. In 159, he published his Amphitheatrum Sapientiae Aeternae (Amphitheatre of Eternal Wisdom) in Hamburg, which contains the engraving by Paullus van der Doort of the drawing credited to Hans Vredeman de Vries (1527–1604) entitled The First Stage of the Great Work better known as the Alchemist’s Laboratory.

Heinrich Khunrath Source. Wikimedia Commons
Amphitheatrum Sapientiae Aeternae title page Source: Wikimedia Commons
The First Stage of the Great Work better known as the Alchemist’s Laboratory. Source: Wikimedia Commons

Khunrath was one of the alchemists, who spent time on the court of the Holy Roman Emperor, Rudolf II, also serving as his personal physician.

Rudolf II portrait by  Joseph Heintz the Elder, 1594. Source: Wikimedia Commons

Rudolf ran several laboratories and attracted alchemists from over all in Europe.

Underground alchemical laboratory Prague Source

John Dee and Edward Kelly visited Rudolf in Prague during their European wanderings. Oswald Croll (c. 1563–1609) another Paracelsian physician, who visited Prague from 1597 to 1599 and then again from 1602 until his death, dedicated his Basilica Chymica (1608) to Rudolf.

Title page Basilica Chymica, Frankfurt 1629 Source: Wikimedia Commons

The Polish alchemist and physician Michael Sendivogius (1566–1623), who in his alchemical studies made important contributions to chemistry, is another who gravitated to Rudolf in Prague in 1593.

19th century representation of the alchemist Michael Sendivogius painted by Jan Matejko Art Museum  Łódź via Wikimedia Commons

His De Lapide Philosophorum Tractatus duodecim e naturae fonte et manuali experientia depromti also known as Novum Lumen Chymicum (New Chemical Light) was published simultaneously in Prague and Frankfurt in 1604 and was dedicated to Rudolf.

Michael Sendivogius Novum Lumen Chymicum 

The German alchemist and physician Michael Maier (1568–1622), author of numerous hermetic texts, served as Rudolf’s court physician beginning in 1609. 

Engraving by Matthäus Merian of Michael Maier on the 12th page of Symbola avreae mensae dvodecim nationvm Source: Wikimedia Commons

Along with Rudolf’s Prague the other major German centre for Paracelsian alchemical research was the landgrave’s court in Kassel. Under Landgrave Wilhelm IV (1532–1592), the court in Kassel was a major centre for astronomical research. His son Moritz (1572–1632) turned his attention to the Paracelsian chymiatria, establishing a laboratory at his court.

Landgrave Moritz engraving by Matthäus Merian from Theatrum Europaeum Source: Wikimedia Commons

Like Rudolf, Moritz employed a number of alchemical practitioners. Hermann Wolf (c. 1565­ 1620), who obtained his MD at the University of Marburg in 1585 and was appointed as professor for medicine there in 1587, served as Moritz’s personal physician from 1597. Another of Moritz’s personal physicians was Jacob Mosanus (1564–1616, who obtained his doctorate in medicine in Köln in 1591. A Paracelsian, he initially practiced in London but came into conflict with the English authorities. He moved to the court in Kassel in 1599. He functioned as Moritz’s alchemical diplomat, building connection to other alchemists throughout Europe. Another of the Kasseler alchemists was Johannes Daniel Mylius (1585–after 1628). When he studied medicine is not known but from 1612 in Gießen he, as a chymiatriae studiosus, carried out chemical experiments with the support and permission of the landgrave. In 1613/14 and 1616 he had a stipend for medicine on the University of Marburg. He was definitely at Moritz’s court in Kassel in 1622/23 and carried out a series of alchemical experiment there for him. How long he remained in Kassel is not known. He published a three volume Opus medico-chymicum in 1618 that was largely copied from Libavius’ Alchemia (see below)

Astrological symbol from Opus medico-chymicum Source: Wikimedia Commons

The most important of Moritz’s alchemist was Johannes Hartmann (1568–1631), Mylius’ brother-in-law.

Johannes Hartmann engraving by Wilhelm Scheffer Source: Wikimedia Commons

Hartmann originally studied mathematics at various Germany universities and was initially employed as court mathematicus in Kassel in 1591. In the following year he was appoint professor for mathematics at the University of Marburg by Moritz’s father, Wilhelm. In the 1590s, together with Wolf and Mosanus he began to study alchemy and medicine in the landgraves’ laboratory. In 1609, Moritz appointed Hartmann head of the newly founded Collegium Chymicum on the University of Marburg and professor of chymetria. Hartmann established a laboratory at the university and held lecture courses on laboratory practice. 

Collected works of Johannes Hartmann Source

The four German chymetria laboratory centres that I have sketched were by no means isolated. They were interconnected with each other both by correspondence and personal visits, as well as with other Paracelsian alchemists all over Europe. Both Croll and Maier although primarily associated with Rudolf in Prague spent time with Moritz in Kassel.

I now turn to Denmark, which in some senses was an extension of Germany. Denmark was Lutheran Protestant, German was spoken at the Danish court and many young Danes studied at German universities. Peder Sørensen (1542–1602), better known as Petrus Severinus, was one of the leading proponents of Paracelsian iatromedicine in Europe. It is not known where Severinus acquired his medical qualifications. In 1571, he became personal physician to King Frederick II until his death in 1588 and retained his position under Christian IV. In 1571, he published his Idea medicinæ philosophicæ, which was basically a simplified and clear presentation of the iatromedical theories of Paracelsus and was highly influential. 


Severinus moved in the same social circles as Tycho Brahe (1546–1601) and the two were friends and colleagues. Severinus’ medical theories had a strong influence on the astronomer and Tycho also became an advocate and practitioner of Paracelsian alchemical medicine.

Portrait of Tycho Brahe at age 50, c. 1596, artist unknown Source: Wikimedia Commons

When Tycho began to construct his Uraniborg on the island of Hven in 1576, he envisaged it as temple dedicated to the muses of arts and sciences. The finished complex was not just a simple observatory but a research institute with two of the most advanced observatories in Europe, a papermill, a printing works and in the basement an alchemical laboratory with sixteen furnaces for conduction distillations and other chemical experiments.

An illustration of Uraniborg. The Tycho Brahe Museum Alchemical laboratory on the left at the bottom

Tycho took his medical research very seriously developing medicines with which he treated colleagues and his family.

In the south of Germany Andreas Libavius (c. 1550–1616) took the opposite path to Severinus, he totally rejected the philosophies of Paracelsus, which he regarded as mystical rubbish, whilst at the same time embracing chymetria. Having received his MA in 1581, somewhat late in life in 1588, he began to study medicine at the University of Basel. In 1591, he was appointed city physician in Rothenburg ob der Taube, later being appointed superintendent of schools. 

Andreas Libavius artist unknown Source: Wikimedia Commons

In 1597, Libavius published his Alchemia, an alchemical textbook, a rarity in a discipline that lived from secrecy. It was written in four sections: what to have in a laboratory, chemical procedures, chemical analysis, and transmutation. Although, Libavius believed in transmutation he firmly rejected the concept of an elixir of life. In the laboratory section of his Alchemia, he contrasted Tycho’s laboratory on Hven, which, being Paracelsian, he viewed as defective with his own vision of an ideal alchemical laboratory.

Source:Wikimedia Commons

Roughly contemporaneous with Libavius, the German physician and alchemist Daniel Sennert (1572­–1637), who played a significant role in the propagation of atomic theory in chemistry, introduced practical laboratory research into his work in the medical faculty of the University of Wittenberg. Sennert represents the beginning of the transition of the laboratory away from the courts of the rulers and aristocrats into the medical faculties of the universities. 

Portrait of Daniel Sennert engraved by Matthäus Merian Source: Wikimedia Commons

During the seventeenth century the medical, alchemical laboratory gradually evolved into a chemical laboratory, whilst remaining a part of the university medical faculty, a transmutation[1] that was largely complete by the early eighteenth century. Herman Boerhaave (1668 – 1738), regarded as one of the founders of modern chemistry in the eighteenth century, his Elementa Chemiae (1732) was one of the earliest chemistry textbooks, was professor of medicine at Leiden University. A generation earlier, Robert Boyle (1627–1691), who ran his own private laboratory, and whose The Sceptical Chymist (1661) was a transitional text between alchemy and chemistry, was still a practicing alchemist, although he rejected the theories of Paracelsus.  

[1] Pun intended

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Filed under History of Alchemy, History of Chemistry, History of medicine, History of science, Renaissance Science

The swashbuckling, philosophical alchemist

If you go beyond the big names, big events version of the history of science and start looking at the fine detail, you can discover many figures both male and female, who also made, sometime significant contribution to the gradual evolution of science. On such figure is the man who inspired the title of this blog post, the splendidly named Sir Kenelm Digby (1603–1665), who made contributions to a wide field of activities in the seventeenth century.

Kenelm Digby (1603-1665) Anthony van Dyck Source: Wikimedia Commons

To show just how wide his interests were, I first came across him not through my interest in the history of science, but through my interest in the history of food and cooking, as the author of an early printed cookbook, The Closet of the Eminently Learned Sir Kenelme Digbie Kt. Opened (H. Brome, London, 1669).

Source: Wikimedia Commons

Born 11 June in Gayhurst, Buckinghamshire, in 1603 into a family of landed gentry noted for their nonconformity, he, as we will see, lived up to the family reputation. His grandfather Everard Digby (born c. 1550) was a Neoplatonist philosopher in the style of Ficino, and fellow of St John’s College Cambridge, (Fellow 1573, MA 1574, expelled 1587), who authored a book that suggested a systematic classification of the sciences in a treatise against Petrus Ramus, De Duplici methodo libri duo, unicam P. Rami methodum refutantes, (Henry Bynneman, London, 1580, and what is considered the first English book on swimming, De arte natandi, (Thomas Dawson, London, 1587). The latter was published in Latin but translated into English by Christopher Middleton eight years later. 

Source: Wikimedia Commons
Source: Wikimedia Commons

His father Sir Everard Digby (c. 1578–1606) and his mother Mary Mulsho of Gayhurst were both born Protestant but converted to Catholicism.

Sir Everad Digby artist unknown Source: Wikimedia Commons

His father was executed in 1606 for his part in the Gunpowder Plot and Kenelm was taken from his mother and made a ward first of Archbishop Laud (1573–1645) and later of his uncle Sir John Digby (1508-1653), who took him on a sixth month trip (August 1617–April 1618) to Madrid in Spain, where he was serving as ambassador.

Sir John Digby portrait by Cornelis Janssens van Ceulen Source: Wikimedia Commons

Returning from Spain, the fifteen-year-old Kenelm entered Gloucester Hall Oxford, where he came under the influence of Thomas Allen (1542–1632).

Thomas Allen by James Bretherton, etching, late 18th century Source: wikimedia Commons

 Thomas Allen was a noted mathematician, astrologer, geographer, antiquary, historian, and book collector. He was connected to the circle of scholars around Henry Percy, Earl of Northumberland (1564–1632), the so-called Wizard Earl, through whom he became a close associate of Thomas Harriot (c. 1560–1621). Through another of his patrons Robert Dudley, Early of Leicester, (1532–1588) Allen also became an associate of John Dee (1527–c. 1608). Allen had a major influence on Digby, and they became close friends. When he died, Allen left his book collection to Digby in his will: 

… to Sir Kenelm Digby, knight, my noble friend, all my manuscripts and what other of my books he … may take a liking unto, excepting some such of my books that I shall dispose of to some of my friends at the direction of my executor.

Digby donated this very important collection of at least 250 items, which contained manuscripts by Roger Bacon, Robert Grosseteste, Richard Wallinford, amongst many others to the Bodleian Library.

Digby left Oxford without a degree in 1620, not unusual for a member of the gentry, and took off on a three-year Grand Tour of the continental. In France Maria de Medici (1575–1642) is said to have cast an eye on the handsome young Englishman, who faked his own death and fled France to escape her clutches. In Italy he became accomplished in the art of fencing. In 1623 he re-joined his uncle in Madrid, this time for a nearly a year and became embroiled in the unsuccessful negotiations to arrange a marriage between Prince Charles and the Infanta Maria. Despite the failure of this mission, when he returned to England in 1623, the twenty-year-old Kenelm was knighted by James the VI &I and appointed a Gentleman to Prince Charles Privy Chamber at the time converting to Anglicanism. In 1625 he secretly married his childhood sweetheart Venetia Stanley (1600–1633). They had two sons Kenelm (1626) and John (1627) before the marriage was made public. 

Venetia, Lady Digby by Anthony van Dyck Source: Wikimedia Commons

Out of favour with Buckingham, Digby now became the swashbuckler of the title. Fitting out two ships, the 400-ton Eagle under his command and the 250-ton Barque under the command of Sir Edward Stradling (1600–1644), he set off for the Mediterranean to tackle the problem of French and Venetian pirates, as a privateer, a pirate sanctioned by the crown.

Arbella, previously the Eagle Digby’s flagship

Capturing several Flemish and Dutch prize on route, on 11 June 1628 they attacked the French and Egyptian ships in the bay of Scanerdoon, the English name for the Turkish port of Iskender. Successful in the hard-fought battle, Digby returned to England with both ships loaded down with the spoils, in February 1629, where he was greeted by both the King and the general public as a hero. He was appointed a naval administrator and later Governor of Trinity House. 

The next few years were spent in England as a family man surrounded by a circle of friends that included the poet and playwright Ben Johnson (1572–1637), the artist Anthony van Dyck (1599–1641), the jurist and antiquary John Seldon (1584–1654), and the historian Edward Hyde (1609–1674) amongst many others. Digby’s circle of friends emphasises his own scholarly polymathic interests. His wife Venetia, a notable society beauty, died unexpectedly in 1633 and Digby commissioned a deathbed portrait and from van Dyck and a eulogy by Ben Johnson, now partially lost. 

Venetia Stanley on her Death Bed by Anthony van Dyck, 1633, Dulwich Picture Gallery Source: Wikimedia Commons

Digby stricken by grief entered a period of deep mourning, secluding himself in Gresham College, where he constructed a chemical laboratory together with the Hungarian alchemist and metallurgist János Bánfihunyadi (Latin, Johannes Banfi Hunyades) (1576–1646), where they conducted botanical experiments. 

In 1634, having converted back to Catholicism he moved to France, where he became a close associate of René Descartes (1596–1650). He returned to England in 1639 and became a confidant of Queen Henrietta Maria (1609–1669) and becoming embroiled in her pro-Catholic politics made it advisable for him to return to France.

Henrietta Maria portrait by Anthony van Dyck Source: Wikimedia Commons

Here he fought a duel against the French noble man Mont le Ros, who had insulted King Charles, and killed him. The French King pardoned him, but he was forced to flee back to England via Flanders in 1642. Here he was thrown into goal, however his popularity meant that he was released again in 1643 and banished, so he returned to France, where he remained for the duration of the Civil War.

Henrietta Maria established a court in exile in Paris in 1644 and Digby was appointed her chancellor. In this capacity he undertook diplomatic missions on her behalf to the Pope. Henrietta Maria’s court was a major centre for philosophical debates with William Cavendish, the Earl of Newcastle, his brother Charles both enthusiastic supporters of the new sciences, William’s second wife Margaret Lucas, who had been one of Henrietta Maria’s chamber maids and would go on to great notoriety as Margaret Cavendish prominent female philosopher, Thomas Hobbes, and from the French side, Descartes, Pierre Gassendi (1592–1655), Pierre Fermat (1607–1665), and Marin Mersenne. Digby was in his element in this society.

Margaret Cavendish and her husband, William Cavendish, 1st Duke of Newcastle-upon-Tyne portrait by Gonzales Coques Source: Wikimedia Commons

After unsuccessfully trying to return to England in 1649, in 1653, he was granted leave to return, perhaps surprisingly he became an associate of Cromwell, whom he tried, unsuccessfully, to win for the Catholic cause. He spent 1657 in Montpellier to recuperate, but returned to England in 1658, where he remained until his death. 

He now became friends with John Wallis (1616–1703), Robert Hooke (1635–1703), and Robert Boyle (1627–1691) and was heavily involved in the moves to form a scientific society, which would lead to the establishment of the Royal Society of which he was a founder member. On 23 January 1660/61 he read his paper A discourse concerning the vegetation of plants before the founding members of the Royal Society at Gresham College, which was the first formal publication to be authorised by that still unnamed body. The Discourse would prove to be his last publications, as his health declined, and he died in 1665.

Source: Wikimedia Commons

Up till now the Discourse is the only publication that I’ve mentioned, but it was by no means his only one. Digby was a true polymath publishing works on religion, A Conference with a Lady about choice of a Religion(1638), Letters… Concerning Religion (1651), A Discourse, Concerning Infallibility in Religion (1652). Autobiographical writings including, Articles of Agreement Made Betweene the French King and those of Rochell… Also a Relation of a brave and resolute Sea Fight, made by Sr. Kenelam Digby (1628), and Sr. Kenelme Digbyes honour maintained (1641). Critical writings on Sir Thomas Browne, Observations upon Religio Medici (1642), and on Edmund Spencer, Observations on the 22. Stanza in the 9th Canto of the 2d. Book of Spencers Faery Queen (1643). 

What, however, interests us here are his “scientific” writings. The most extensive of these is his Two Treatises, in One of which, the Nature of Bodies; in the Other, the Nature of Mans Soule, is looked into: in way of discovery, of the Immortality of Reasonable Soules originally published in Paris in 1644 but with further editions published in London in 1645, 1658, 1665, and 1669. Although basically still Aristotelian, this work shows the strong influence of Descartes and contains a positive assessment of Galileo’s Two New Sciences, which was still relatively unknown in England at the time. It also contains a form of mechanical atomism, which, however, is different to those of Epicure or Descartes.


Digby’s most controversial work was his A late discourse made in solemne assembly … touching the cure of wounds by the powder of sympathy, originally published in French in 1658 and then translated into English in the same year. This was a discourse that Digby had held publicly in Montpellier during his recuperation there.


This was a variation on Weapon Salve, an ointment that was applied to the weapon that caused a wound rather than to the wound itself. Digby was by no means the first to write positively about this supposed cure. It has its origins in the theories of Paracelsus and the Paracelsian physician Rudolph Goclenius the Younger (1572–1621), professor at the University of Marburg, first published on it in his Oratio Qua defenditur Vulnus Non Applicato Etiam Remedio, in 1608. In England the divine William Forster (born 1591), the physician and alchemist Robert Fludd (1574–1637), and the philosopher Francis Bacon (1561–1626) all wrote about it before Digby, but it was Digby’s account that attracted the most attention and ridicule. In 1687, an anonymous pamphlet suggested using it to determine longitude. A dog would be wounded with a blade and placed aboard a ship before it sailed. Then every day at noon the weapon salve would be applied to the blade causing the dog to react, thus tell those on board that it was noon at their point of departure. 

Also in 1658, John Wallis dedicated his Commercium epistolicum to Digby who was also author of some of the letters it contained.

John Wallis by Sir Godfrey Kneller Source: Wikimedia Commons

In 1657, Wallis had published his Arithmetica Infinitorum, an important contribution to the development of calculus.


Digby brought the book to the attention of Pierre Fermat and Bernard Frénicle de Bessy (c. 1604 – 1674) in France, Fermat wrote a letter to the English mathematician, posing a series of problems to be solved. Wallis and William Brouncker (1620–1684), who would later become the first president of the Royal Society, took up the challenge and an enthusiastic exchange of views developed between the French and English mathematicians, with Digby acting as conduit for the correspondence. Wallis collected the letter together and published them as his Commercium epistolicum

As already stated, A discourse concerning the vegetation of plants was Digby’s final publication and was to some extent his most interesting. Digby was interested in the question of how to revive dying plants and his approach was basically alchemical. He argued that saltpetre was necessary to the process of revival and that it attracted vital air, which is the food of the lungs. He is very obviously here close to discovering oxygen and in fact he supports his argument with the information that Cornelius Drebbel had used saltpetre to refresh the air in his submarine. In the paper he also hypothesises something very close to photosynthesis. Others such as Jan Baptist van Helmont (1580–1644) were conducting similar investigations at the time. These early investigations would lead on in the eighteenth century to the work of Stephen Hales (1677–1761) and the pneumatic chemists of the eighteenth century. 

Digby made no major contributions to the advancement of science, but he played a central role as facilitator and mediator between groups of philosophers, mathematicians, and scientists promoting and stimulating discussions in both France and England in the first half of the seventeenth century. He also played an important role in raising the awareness in England of the works of Descartes and Galileo. Although largely forgotten today, he was in his own time a respected member of the scientific community.

Digby is best remembered, today, for two things, his paper on the powder of sympathy, which I dealt with above, and his cookbook, to which I will now return. The Closet of the Eminently Learned Sir Kenelme Digbie Kt. Opened was first published posthumously by one of his servants in 1669 and has gone through numerous editions down to the present day, where it is regarded as a very important text on Early Modern food history. However, this was only one part of his voluminous recipe collection. Two other parts were also published posthumously. Choice and experimental receipts in physick and chirugery was first published in 1668 and went through numerous editions and translation by 1700, and A choice collection of rare chymical secrets and experiments in philosophy first published in 1682, which also saw many editions. What we have here is not three separate recipe collections covering respectively nutrition, medicine, and alchemy but three elements of a related recipe spectrum. We find a similar convolute in the work of Katherine Jones, Viscountess Ranelagh (1615–1691), Robert Boyle’s sister, an alchemist/chemist in her own right and an acquaintance of Digby’s. 

There is little doubt in my mind that Sir Kenelm Digby Kt. was one of the most fascinating figures of the seventeenth century, a century rich in fascinating figures. 

As was also believed when he died on his birthday in 1665, his epitaph read

‘Under this Tomb the Matchless Digby lies;

Digby the Great, the Valiant, and the Wise:

The Ages Wonder for His Nobel Parts;

Skill’d in Six Tongues, and Learn’d in All the Arts.

Born on the Day He Dy’d, Th’Eleventh of June,

And that Day Bravely Fought at Scanderoun.

‘Tis Rare, that one and the same Day should be

His Day of Birth, of Death, and Victory.’


Filed under History of Alchemy, History of Chemistry, History of Mathematics, History of science

Renaissance Science – XXIII

Without doubt, one of the most eccentric and certainly one of the most controversial figures of the entire Early Modern period was the iconoclastic Swiss physician Theophrastus von Hohenheim (c. 1493–1541), more popularly known as Paracelsus. Trying to write about Paracelsus is complicated by the fact that he is the source of numerous myths and legends. Even if one resorts to the old maxim of Sergeant Joe Friday in the 1950s American radio series Dragnet, “just the facts ma’am”,* you run into problems. Every fact presented by one Paracelsus researcher has been disputed by at least one other Paracelsus researcher, so I shall just give a sketch of the generally accepted facts about his life then concentrate on his medical theories and their impact in the Early Modern Period.

He was born Theophrastus von Hohenheim the son of Wilhelm Bombast von Hohenheim, an illegitimate descendent of a Swabian aristocratic family, and his wife a bondswoman of the local Benedictine monastery in Einsiedeln in the canton of Schwyz in Switzerland, probably in 1493 or 94. Wilhelm held a Master’s degree in medicine and was physician to the mining community in Einsiedeln. Following the early death of his mother, probably around 1502, his father moved to Villach in Austria, another mining community. 

Aureoli Theophrasti ab Hohenheim. Reproduction, 1927, of etching by A. Hirschvogel, 1538. Source: Wikimedia Commons

It is probable that Theophrastus received his early education from his father in medicine, mining, minerology, botany, and alchemy. Almost nothing in known about his further education other than that he was registered as a Artzney Doctor(Doctor of Medicine) in Strasbourg in 1525 and a year later in Basel he testified that his doctorate was from the University of Ferrara. There is, however, no other evidence to support this claim. He seems to have travelled widely throughout Europe in his youth but, once again, there are no real details of this part of his life. 

In 1525 he settled in Salzburg as a physician, but probably because of the unrest caused by the German Peasant’s War he moved to Strasbourg in 1526. In 1527, he received what should have been a major boost in his career when he was called to Basel to treat the leading humanist publisher Johann Froben (c. 1460–1527), who had been written off by his own doctors, apparently because of a gangrenous foot. During six weeks of treatment in early 1527 Theophrastus succeeded in bringing relief to the publisher and for his efforts was richly rewarded and appointed town physician of Basel. This appointment included not just the right but the obligation to hold lectures at the university. Although he probably didn’t realise it at the time, Theophrastus had reached the apex of his formal career as physician.

1493 woodcut of Basle, from the Nuremberg Chronicle Source: Wikimedia Commons

During his time in Basel, Theophrastus came into contact with many leading humanist scholars, including Erasmus, who had worked for Froben and with whom he carried out a correspondence on theological issues.

Theophrastus’ time in Basel was to put it mildly stormy. He clashed head on with the local medical establishment and began his career as medical iconoclast declaring war on the conventional university medical teachings. He held his lectures in German instead of Latin to make them accessible to everyman and rejected the authority of the standard medical texts, preferring experience and empiricism to book learning. This behaviour reached a high point when he burnt a copy of Avicenna’s Canon of Medicine, probably the most important university medical textbook, on the Basel marketplace in the St John’s Eve fire on 23 June 1527. In February 1528 his brief career as an establishment physician came to an end and Theophrastus left Basel for what would turn out to be a life as an itinerant physician until his death in 1541. 

In 1529, Theophrastus moved to the city of Nürnberg, in the early sixteenth century, one of the richest cities in Europe and a major centre for both the mathematical science including astrology and medicine. His aim was to establish himself in the thriving and lucrative market for medical books. Here he decided to enter the rumbling syphilis debate. The disease had first appeared in Europe in the late fifteenth century and in fact only obtained the name, syphilis, from Girolamo Fracastoro (c. 1477–1553) in 1530. In 1529, there were two competing “cures” for syphilis, mercury, and guaiac wood. Theophrastus took up arms for mercury and against guaiac wood. He published one short pamphlet and a longer text on the topic with success. Unfortunately, the import from guaiacum wood from Brazil was financed by the Fugger banking house and the influential Leipziger physician Heinrich Stromer von Auerbach, a Fugger client, persuaded the Nürnberger medical establishment to block a planned major work from Theophrastus on the subject. Stromer’s influence throughout the German medical establishment served to effectively end Theophrastus’ medical publishing career before it had really started.

Heinrich Stromer von Auerbach Source: Wikimedia Commons

This medical publishing block led to Theophrastus adopting the name Paracelsus, a toponym for Hohenheim, for his future publication. In late 1529, he published an astrological pamphlet under the name Theophrastus Paracelsus and a short tract on the Comet of 1531 simply under the name Paracelsus. He proved to be a fairly successful astrological author and the majority of his publication up till his death were astrological.

From now on Theophrastus, blocked by the medical establishment was forced to live from treating rich private patient. He had a brief change of fortune in 1536, when he succeeded in getting his Die große Wundarzney (Great Book of Surgery) published by Heinrich Steiner (before 1500–1548) in Augsburg. The book was a success with, to Theophrastus’ annoyance, pirate editions appearing in both Ulm and Frankfurt in the same year. It remained a much-read reference work for more than a century. Theophrastus’ live continued to go downhill until his relatively early death in 1541.

Title page from ‘Der grossen Wundartzney’ (Great Surgery Book, 1536) by the Swiss alchemist and physician Paracelsus (1493-1541). Source

By the time of his death Theophrastus could be regarded as a failure. He had manged to publish little in the way of medical literature and apart from his brief time in Basel had held no important medical positions. He had succeeded in antagonising and alienating the medical establishment and was better known for his scandals than for any contributions to medicine. If his story had ended there, he would have become a mere footnote in the history of medicine as the man, who had publicly burnt a medical textbook on St John’s Eve in Basel in 1527. However, his story experienced a remarkable posthumous renaissance, which began about twenty years after his death.

Theophrastus had written a large number of books and tracts outlining his heterodox medical philosophy, none of which were published in his lifetime. Beginning in 1560, what might be termed his fan club–Adam von Bodenstein (1528–1577), Michael Toxites (1514–1581), Gerhard Dorn (c. 1530–1584), all of them physicians and alchemists–began to publish these texts, a process that culminated in the publication of a ten-volume edition of his medicinal and philosophical treatises under the title Bucher und Schriften by Johann Huser (c. 1545–1600) in Basel from 1598 to 1591. Huser’s edition of Theophrastus’ surgical publications appeared posthumously in 1605. It is in the last third of the sixteenth century that Paracelsian medicine became a serious discipline but what was it?

Paracelsus’ medical philosophy was a complex melange of religion, astrology, alchemy, and straight forward weirdness. He was first and foremost deeply religious and fundamentally Christian. He regarded himself, above everything else, as a religious reformer and a prophet. His religious stance was at the core of his rejection of the medicine taught at the European medieval universities. Greek and Islamic medicine were both heathen and thus to be rejected. Paracelsus insisted that his medicine was one hundred percent Christian. His rejection of Greek knowledge, of course, cost him any support he might have received from the humanists, who completely rejected him. 

At the centre of his philosophy was the macrocosm/microcosm, as above so below, concept that lay at the heart of the justification for astrology. This viewed the human body as a miniature model of the cosmos, the one affecting the other. Paracelsus took this one step further believing that all the minerals found in the world were found in another form within the human body.  This tied up with his concept of alchemy.

Paracelsus’ alchemy was not the alchemy of transmuting base metals into gold and silver but a medical alchemy. This was not a new thing, The Franciscan alchemist Jean de Roquetaillade, also known as John of Rupescissa (c. 1310–c. 1368) had emphasised the use of distillation to produce medicinal elixirs in his De Consideratione Quintae Essentiae (On the Consideration of the Quintessence of all Things).

Manuscript of Rupescissa c. 1350

This very popular text was reworked and integrated into the Pseudo-Lullian Liber de secretis naturae (Book of the Secrets of Nature). Paracelsus knew both works well. Believing like cures like, Paracelsus developed alchemical mineral cures that would act upon the minerals he believed to be in the body. He also believed that the organs of the body were organic alchemical apparatuses, there being an alchemical furnace at the centre of the body. Philosophically, borrowing from the Aristotelian belief that all metals originated from two principles present in different quantities, which Abu Mūsā Jābir ibn Hayyān named Mercury and Sulphur, in the eighth century. He believed that all matter consisted of three principles, his tria prima, Mercury, Sulphur, and Salt. A tripartite concept mirroring the Holy Trinity. I’m not going to go any deeper into this aspect of his alchemy or how it related to the traditional four element matter theory, but I will point out that it eventually led to the phlogiston theory in the seventeenth century. 

It was Paracelsus’ medical alchemy that his followers took up during the posthumous renaissance of his work, rechristening it chymiatria or iatrochemistry. This renaissance mostly took place not in the universities, the university professors of medicine rejecting the book burning iconoclast, but on the courts of various European rulers. First and foremost, Ernst of Bayern (1554­–1611), archbishop of Cologne, who was Johan Huser’s patron. Earlier the elector Palatine Ottheinrich (1502–1559) had been an enthusiastic supporter of Paracelsus. Later the Holy Roman Emperor Rudolf II (1552–1612), Wolfgang II von Hohenlohe (1546–1610), and Moritz von Hessen-Kassel (1572–1632) were all important patrons of Paracelsian alchemy. The University of Marburg boasts that they have the world’s first professorship for chemistry, but, in fact, the chair founded by Moritz von Hessen-Kassel, with the appointment of Johannes Hartmann (1561–1638) in 1609, was for Paracelsian iatrochemistry. 

Johannes Hartmann Source: Wikimedia Commons

The chair in Marburg was followed in the seventeenth century by several other new chairs all of them being chymiatria, and closely connected with the medical departments, rather than what is now known as chemistry. However, this adoption of Paracelsian chymiatria marks two different developments. Firstly, it is the beginning of pharmacology, of which Paracelsus is often called the founder. In Germany many pharmacies are still named after him. Secondly, it is an important development in the transition from alchemy to modern chemistry, a process that took place throughout the seventeenth and eighteenth centuries, with chemists, in the modern sense, in the eighteenth century strongly denying that their discipline ever had anything to do with alchemy. 

There were notable cases of scholars in the seventeenth century adopting and contributing to these developments in chymiatria, whilst stridently distancing themselves from Paracelsus and his “magic”. One notable example is Andreas Libavius (c.1550–1616), whose Alchymia (1597 is often cited as the first chemistry textbook.

Source: Wikimedia Commons

In his rejection of Paracelsus, he refers back to Pseudo-Lull and other medieval sources, claiming that Paracelsus was merely derivative. Another chemically inclined rejector of Paracelsus was Jan Baptist van Helmont (1580–1644). The heated debates between the Paracelsians, the convention physicians who rejected his alchemical medicine and those who accepted it, but vehemently rejected the man actually helped to spread his ideas. 

L0003194 Portrait of J.B. van Helmont, Aufgang…1683 Credit: Wellcome Library, London. Wellcome Images Portrait of J.B. van Helmont. Engraving Aufgang der Artzney-Kunst… Jean Baptiste van Helmont Published: 1683 Copyrighted work available under Creative Commons Attribution only licence CC BY 4.0

One highly influential Paracelsian, who should get a brief mention, is the Dane Peder Sørensen (1542–1602), better known as Petrus Severinus, who became chancellor of Denmark. In 1571 he published his Idea medicinae philosophicae (Ideal of Philosophical Medicine) (1571), which asserted the superiority of the ideas of Paracelsus to those of Galen and was highly influential, above all because it was written in Latin, the language of the learned rather than Paracelsus’ preferred German.


The German physician Daniel Sennert (1572–1637) author of De chymicorum cum Aristotelicis et Galenicis consensu ac dissensu (On the Agreements and Disagreements of the Chymists with the Aristotelians and Galenists) (1619), who became professor of medicine in Wittenberg, was highly influenced by Severinus, although he was one of those, who rejected Paracelsus the man. It was Sennert, who was most important in introducing the concept of atomism taken from the medieval alchemist Paul of Taranto (13th century) into the seventeenth century scientific debate exercising a major influence on Robert Boyle (1527–1691).

Source:Wikimedia Commons

Another important scholar influenced by Severinus was the Frenchman Guy de La Brosse (1586–1641) physician to King Louis XII and director of the first botanical garden in Paris Le Jardin du Roi founded in 1635. His support of Paracelsian medicine was particularly significant as the medical faculty of the university in Paris was vehemently anti-Paracelsus.

Le Jardin du Roi Paris

Perhaps Severinus’ most interesting follower was the astronomer, Tycho Brahe (1546–1601). It was Severinus, as Denmark’s most powerful politician, who persuaded the king to set up Tycho’s astronomical observatory on Hven, where Tycho also built a laboratory to produce Paracelsian medicines. 

To close a brief look at Paracelsus the physician beyond his chymiatria. Shut out by the medical establishment from the universities and the lucrative medical book market, Paracelsus must have been a successful physician, as he survived over the years on his reputation for healing wealthy private patients. In his polemics on the study of medicine, Paracelsus rejected book learning in favour of empirical observation and experience. He very much favoured hands on artisanal knowledge over, what he considered, the intellectual posturing of the university physicians. All of this places him very much in line with the general trends in Renaissance science, although he was certainly more radical than most of his contemporaries. His insistence on empirical observation is most notable in two areas where he made fairly novel contributions.

Paracelsus is credited with making one of the first studies of occupational diseases. His work in this direction is based on his observations of the typical diseases of the miners working in the areas where his father was employed and where he also worked from time to time. The second area where Paracelsus distinguished himself is in his analysis of mental illness. Although his writings on the subject are to a certain extent confused and complex, he does present some remarkable insights. He clearly distinguishes between genetic mental deficiency and mental illness. He diagnosed what we would now call manic-depression and was probably the first physician to recognise the existence of psychosomatic illnesses. Lastly, his suggested treatments for the mentally ill were positively humane compared to most of his contemporaries. All of this was very much based on clear-eyed empirical observation.

Theophrastus von Hohenheim is a very complex historical figure and it is almost impossible to do him justice in a brief blog post, but, however one views him, there is no denying that he had a major influence during the Renaissance both in the promotion of iatrochemistry and the turn away from book learning towards empirical investigation, perhaps the principle distinguishing feature of Renaissance science.

*Like many an oft quoted catch phrase, Sergeant Joe Friday never actually said “just the facts ma’am”. It only turns up in Stan Freburg’s brilliant Dragnet parody “St. George and the Dragonet” (1953), which is where I know it from, never actually having heard the original Dragnet.

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Filed under History of Chemistry, History of medicine, Renaissance Science

Not just an elder sister

How do you write a biography of an intellectual woman, who was a major, significant figure in the scientific, social, and political circles of her time, but who, although she wrote extensively, published almost nothing and whose personal papers were scattered following her death and have over time mostly disappeared, leaving only faint traces of her existence dispersed in obscure archives spread over a handful of countries? In her biography of Lady Ranelagh, Michelle DiMeo delivers up a masterclass in how to achieve this seemingly impossible task. Once again, many regular readers of this blog are probably thinking, who is Lady Ranelagh and why is Thony writing about her? All becomes clearer if I quote the full title of DiMeo’s book, Lady RanelaghThe Incomparable Life of Robert Boyle’s Sister.[1]  

Lady Ranelagh was born Katherine Boyle, on 22 March 1615, the seventh of fifteen children to Catherine Fenton and Richard Boyle, the first Earl of Cork, an important and influential Anglo-Irish politician. She was twelve years older than her more famous brother Robert, who was the fourteenth child and seventh son born in 1627. If people know anything at all about the relationship of the two it is the fact that they shared a house in London from 1668 until they both died in 1691. However, as my title states Katherine was not just Robert’s elder sister but was a significant and influential figure in intellectual circles in England in the second half of the seventeenth century, in her own right and definitely exercised that influence in Robert’s own developments, in particular as a chemist. It is this story that DiMeo has carefully and skilfully excavated from the seemingly meagre sources available to the historian for Katherine Jones, Viscountess Ranelagh’s fascinating life.

Katherine’s life falls roughly into seven segments and after an introduction in which DiMeo discusses previous work done on Katherine’s life and work and also lays out her own decisions on technical matters, our author deals with each of those segments chronologically, always embedding the available information about Katherine in a rich web of historical context, which allows the reader to create a full picture of what it was like to be an intelligent, forceful and resourceful woman from an aristocratic background in seventeenth century Ireland and England.

The first segment deals with her childhood and young adulthood as a daughter of a politically power-hungry aristocrat. She would have received little education, which makes her later achievements all the more remarkable, and she was basically just a bargaining chip in Richard Boyle’s strategies to win more power and wealth. Bargained off in marriage to the son of one potential ally, at a very early age, in a deal that fell through when the potential father-in-law died, she was then delivered up to the son of another in the power brokerage game and became the wife, at the age of fifteen, of Arthur Jones, the future Viscount of Ranelagh. Unfortunately, Arthur Jones proved to be anything but a good husband and father and in 1642, it should be noted aged just twenty-seven, following trials and tribulations in a Catholic uprising, Katherine took the extraordinary step of leaving both Ireland and her husband, and taking her four children with her, decamped for England.

It is now that the Lady Ranelagh, who is interesting for those concerned with the history of science, comes into being and the next two sections of DiMeo book are devoted to this blossoming of an influential seventeenth century woman of science. Katherine became a member of the Hartlib Circle. Samuel Hartlib (c. 1600–1662) was a German polymath, who actively promoted his ideas on science, medicine, agriculture, politics, religion, and education within an informal group of like-minded thinkers and supporters, mainly in England but also in continental Europe, largely through correspondence. This informal group was, unusual for the time, open to women and Katherine became an active member, taking an informed interest in all of the topics listed above. This was for me the most interesting part of the book, because far too little attention is in general paid to the Hartlib Circle, one of the important predecessors to the more formal, later Royal Society. 

Katherine was recognised as a well-informed, intelligent and above all pious correspondent within this loose conglomeration of thinkers. Her ability to balance complex scientific and philosophical concepts with a devout moral attitude was much admired. One should always bear in mind that peoples religious beliefs played a significant role in the development of the sciences in the seventeenth century. I won’t go into detail, for that you will have to, and should, read the book, but her thoughts and advice were particularly sort on questions of medicine and chemistry/alchemy, interconnected fields in which women, guardians of a family’s health and welfare were considered knowledgeable. It was also in this phase of her life that Katherine took up the mentorship of her younger brother Robert helping to steer him also towards the deep interest in medicine and chemistry that would characterise his career as a natural philosopher, a common interest that the siblings would share for the rest of their lives.

Unfortunately, Katherine’s strong moral and religious convictions prevented her from ever allowing her fruitful ideas to be published, which would have been unseemly for a woman in the seventeenth century. However, Robert did acknowledge her influence and input in his own writings, whilst never referring to her by name, but always as his sister. DiMeo contrasts and analyses Katherine’s propriety with this famously brazen public performances of her near contemporary Margaret Cavendish, Duchess of Newcastle.

In the 1650s there was a brief interlude where Katherine returned to Ireland to try and assist in sorting out the Boyle family affairs, which had been much disturbed by the uprising that had led to her leaving Ireland at the beginnings of the sixteen forties. Here we see Katherine’s political and diplomatic abilities on display, abilities that she would have to exercise upon her return to England.

Not long after her return to England, Katherine’s role in the intellectual community changed with the dissolution of the Hartlib Circle following the death of its central figure in 1662 and the foundation of the Royal Society in the early sixteen sixties. Unlike the Hartlib Circle the Royal Society remained firmly closed to women. Katherine, however, managed to exercise some influence within intellectual circles through her personal connections and her not inconsiderable diplomatic skills. During the plague and disaster years of 1665-1667, Katherine suffered more trials and tribulations but also continued to exercise a strong social and political influence in English society. It was also here that Robert paid his greatest tribute to his sister’s influence with the publication of a collection of his spiritual reflections, Occasional Reflections upon Several Subjects, which is dedicated to Katherine under the pseudonym, Sophronia. 

Ironically, we know the least about the interaction between Robert and Katherine during the last twenty-three years of their lives, when they shared a house in London. Living together, they no longer needed to correspond and so there is no collection of letters informing us of their exchanges. Nevertheless, even here DiMeo manages to paint a vivid picture of their life together.

DiMeo delivers up in her book a powerful portrait of a very impressive woman who played a significant role in the intellectual life of seventeenth century England and by no means just because she was the elder sister of one of the periods most significant natural philosophers. Having excavated Katherine Jones née Boyle’s life out of the archives DiMeo poses both indirectly and directly the question, as to how many other strong intellectual seventeenth century women have been neglected up till now in our accounts.

Applying meticulous research and equally meticulous analysis of the results of that research, Michelle DiMeo has written an extraordinary book about an extraordinary woman. Expertly written and highly readable, all of DiMeo’s statements are carefully documented in extensive endnotes referencing the primary and secondary sources listed in the equally extensive bibliography. The book is rounded off with a detailed index. This is a book that should be read by anybody and everybody, who expresses an interest in the intellectual, social , and political life of the seventeenth century in both Ireland and England. 

[1] Michelle DiMeo, Lady RanelaghThe Incomparable Life of Robert Boyle’s Sister, University of Chicago Press, Chicago & London, 2021


Filed under Book Reviews, History of Chemistry, Ladies of Science

Microscopes & Submarines

The development of #histSTM in the early decades of the Dutch Republic, or Republic of the Seven United Netherlands, to give it its correct name, was quite extraordinary. Alongside the development of cartography and globe making, the most advanced in the whole of Europe, there were important figures such as the engineer, mathematician and physicist, Simon Stevin, the inventors of the telescope Hans Lipperhey and Jacob Metius, the mathematical father and son Rudolph and Willebrord Snel van Royan and Isaac Beeckman one of the founders of the mechanical philosophy in physics amongst others. However, one of the most strange and wonderful figures in the Netherlands during this period was, without doubt, the engineer, inventor, (al)chemist, optician and showman Cornelis Jacobszoon Drebbel (1571–1631).


Source: Wikimedia Commons

Drebbel is one of those larger than life historical figures, where it becomes difficult to separate the legends and the myths from the known facts, but I will try to keep to the latter. He was born to Jacob Drebbel an Anabaptist in Alkmaar in the province of North Holland. He seems not to have received much formal education but in about 1587 he started attending the Academy of the printmaker, draftsman and painter Hendrick Goltzius (1558–1617) in Haarlem also in North Holland.


Hendrick Goltzius – Self-Portrait, c. 1593-1594 – Google Art Project Source: Wikimedia Commons

Goltzius was regarded as the leading engraver in the Netherlands during the period and he was also an active alchemist. Drebbel became a skilled engraver under Goltzius’ instruction and also acquired an interest in alchemy. In 1595 he married Sophia Jansdochter Goltzius, Hendrick’s younger sister. They had at least six children of which four survived into adulthood. The legend says that Sophia’s prodigal life style drove Drebbel’s continual need to find better sources for earning money.


Drebbel’s town plan of Alkmaar 1597 Source: Wikimedia Commons

Drebbel initially worked as an engraver, cartographer and painter but somewhere down the line he began to work as an inventor and engineer.


Astronomy [from the series The Seven Liberal Arts]. Engraving by Drebbel Source: Wikimedia Commons

Not surprisingly, for a Netherlander, he a turned to hydraulic engineering receiving a patent for a water supply system in 1598. In 1600 he built a fountain at the Noorderpoort in Middelburg and at the end of his life living in England he was involved in a plan to drain the Fens. At some point, possibly when he was living in Middelburg, he learnt the craft of lens grinding, which would play a central roll in his life.

Also in 1598 he acquired a patent for Perpetuum mobile but which he, however, had not invented. The so-called Perpetuum mobile was a sort of clock, which was in reality powered in changes by the air temperature and air pressure had actually been invented by Jakob Dircksz de Graeff (1571–1638), an influential politician and natural philosopher, who was a friend of both Constantijn Huygens and René Descartes, and Dr Pieter Jansz Hooft (1574/5–1636) a politician, physician and schoolteacher.


Jakob Dircksz de Graeff Source: Wikimedia Commons


Pieter Jansz Hooft (1619), Attributed to Michiel van Mierevelt Source: Wikimedia Commons

Drebbel not only patented the Perpetuum mobile but also claimed to have invented it. His increasing reputation driven by this wonder machine earned his an invitation to the court of King James VI &I in London as the guest of the crown prince Henry in 1604. When on the court in London the Queen accidentally broke the Perpetuum mobile, Drebbel was unable to repair it.


The barometric clock of Cornelis Drebbel patented in 1598 and then known as “perpetuum mobile”. Print by Hiesserle von Choda (1557-1665) Source: Wikimedia Commons

At the court in London he was responsible for staging masques, a type of play with poetry, music, dance, and songs that was popular in the sixteenth and seventeenth centuries. He designed and built the stage sets and wonderful machines to enchant the audiences. Drebbel was by no means the only scientist-engineer to be employed to stage such entertainments during the Early Modern Period but he appears to have been very good at it. It was almost certainly Drebbel, who through his contacts imported from the Netherlands the first ever telescope to be seen in England, which was presented to James at the high point of a masque in 1609. He also built a magic lantern and a camera obscura with which he also entertained the members of the court.

Drebbel’s reputation grew to the point where he received an invitation to the court of the Holly Roman Empire, Rudolf II, in Prague in October 1610. Rudolf liked to surround himself with what might be termed wonder workers. Amongst those who had served in this capacity in Prague were Tycho Brahe, John Dee, Edward Kelley, Johannes Kepler and Jost Bürgi. There are no reports of any interactions between Drebbel and either Kepler or Bürgi, who were all on the court of Rudolf at the same time. In Prague he once again functioned as a court entertainer or showman.


AACHEN, Hans von – Portrait of Emperor Rudolf II Source: Wikimedia Commons

Rudolf was deposed by his brother Archduke Mathias in 1611and Drebbel was imprisoned for about a year. Following the death of Rudolf in 1612, Drebbel was released from prison and returned to London. Here, however, his situation was not as good as previously because Henry, his patron, had died in 1612. He kept his head above water as a lens grinder and instrument maker.

As a chemist Drebbel published his best-known written work Een kort Tractaet van de Natuere der Elemente (A short treatise of the nature of the elements) (Haarlem, 1621).


He was supposedly involved in the invention of the explosive mercury fulminate, Hg(CNO)2, but this is disputed. He also developed other explosive mixtures. He invented a chicken incubator with a mercury thermostat to keep it at a constant, stable temperature. This is one of the earliest feedback controlled devices ever created. He also developed and demonstrated a functioning air conditioning system.


Error-controlled regulator using negative feedback, depicting Cornelius Drebbel’s thermostat-controlled incubator of circa 1600. Source: Wikimedia Commons

He didn’t himself exploit one of his most successful discoveries, one that he made purely by accident. He dropped a flask of aqua regia (a mixture of nitric and hydrochloric acid, normally used to dissolve gold) onto a tin windowsill and discovered that stannous chloride (SnCl2) makes the colour of carmine (the red dye obtained from the cochineal insect) much brighter and more durable. Although Drebbel didn’t exploit this discovery his daughters Anna and Catherina and their husbands the brothers, Abraham and Johannes Sibertus Kuffler (a German inventor and chemist) did, setting up dye works originally in Leiden and then later in Bow in London. The colour was known as Colour Kuffler of Bow Dye and was very successful. Kuffler later continued his father-in-law’s development of self-regulating ovens that he demonstrated to the Royal Society.

In the early 1620s Constantijn Huygens, the father of Christiaan, came to London on a diplomatic mission. He made the acquaintance of Drebbel, who demonstrated his magic lantern and his camera obscura for the Dutch diplomat. Huygens was much impressed by his landsman and for a time became his pupil learning how to grind lenses, a skill that he might have passed onto his sons.


Constantijn Huygens (1596-1687), by Michiel Jansz van Mierevelt. Source: Wikimedia Commons

It is not known, who actually invented the microscope and it’s more than likely that the principle of the microscope was discovered by several people, all around the same time, who like Galileo looked through their Galilean or Dutch telescope the wrong way round. What, however, seems to be certain is that Drebbel is the first person known to have constructed a Keplerian telescope, that is with two convex lenses rather than a concave and a convex lens. As with all of his other optical instruments, Drebbel put on microscope demonstration introducing people to the microscopic world, as always the inventor as showman.

Drebbel’s most famous invention was without doubt his submarine. This is claimed to be the first-ever navigable submarine but has become the stuff of legends, how much of story is fact is difficult to assess. His submarine consisted of a wooden frame covered in leather, and one assumes waterproofed in someway; it was powered by oar.


Artistic representation of Drebbel’s submarine, artist unknown Source: Wikimedia Commons

It had bladders inside that were filled with water to enable the submarine to submerge; the bladders were emptied when the vessel was required to surface. In total between 1620 and 1624 Drebbel built three different vessels increasing in size. The final submarine had six oars and could carry up to sixteen passengers. Drebbel gave public demonstrations with this vessel on the river Thames. According to reports the vessel dived to a depth of four to five metres and remained submerged for three hours traveling from Westminster and Greenwich and back again. Assuming the reports to be true, there has been much speculation as to how fresh air was supplied inside the closed vessel. These speculations include a mechanical solution with some form of snorkel as well as chemical solutions with some sort of chemical apparatus to generate oxygen. It is also reported that Drebbel took King James on a dive under the Thames. Despite all of this Drebbel failed to find anybody, who would be prepared to finance a serious use of his submarine.

In the later 1620s Drebbel served the Duke of Buckingham as a military advisor but his various suggestions for weapons proved impractical and failed, the British blaming  the inventor and Drebbel blaming the English soldiers, finally ruining whatever reputation he still had. As already stated above towards the end of his life he was supposedly involved in a scheme to drain the Fens but the exact nature of his involvement remains obscure. Drebbel died in financial straights in 1633 in London, where he was scraping a living running a tavern on the banks of the Thames.

















Filed under History of Alchemy, History of Cartography, History of Chemistry, History of Optics, History of Technology, Renaissance Science

Revealing the secrets of the fire-using arts

During the Middle Ages it was common practice for those working in the crafts to keep the knowledge of their trades secret, masters passing on those secrets orally to new apprentices. This protection of trade secrets, perhaps, reached a peak during the Renaissance in the glassmaking centre of Venice, where anybody found guilty of revealing the secrets of the glassmaking was sentenced to death. Although there were in some crafts manuscripts, which made it into print, describing the work processes involved in the craft these were of very limited distribution. All of this began to change with the invention of moving type book printing. Over the sixteenth and seventeenth centuries printed books began to appear describing in detail the work processes of various crafts. I have already written a post about one such book, De re metallica by Georgius Agricola (1494–1555). However, Agricola’s book was not the first printed book on metallurgy that honour goes to the Pirotechnia of Vannoccio Biringuccio published posthumously in Italian in 1540. Agricola was well aware of Biringuccio’s book and even plagiarised sections of it in his own work.


Title page, De la pirotechnia, 1540, Source: Science History Museum via Wikipedia Commons

Whereas Agricola was himself not a miner or metal worker but rather a humanist physician, whose knowledge of the medieval metallurgical industry was based on observation and questioning of those involved, Biringuccio, as we will see, spent his whole life engaged in one way or another in that industry and his book was based on his own extensive experiences.

Born in Siena 20 October 1480 the son of Lucrezia and Paolo Biringuccio, an architect.


Siena 1568

As a young man Vannoccio travelled throughout Italy and Germany studying metallurgical operations. In Siena he was closely associated with the ruling Petrucci family and after having run an iron mine and forge for Pandolfo Petrucci, he was appointed to a public position at the arsenal and in 1513 director of the mint.


Petrucci coat of arms Source: Wikimedia Commons

He was exiled from Siena in 1516 after the Petruccis fell from power and undertook further travels throughout Italy and visited Sicily in 1517. In 1523 the Petruccis were reinstated and Vannoccio returned to Siena and to his position in the arsenal. In 1526 the Petruccis fell from power again and he was once again forced to leave his hometown. He worked in both the republics of Venice and Florence casting cannons and building fortifications. In 1531 in a period of political peace he returned once more to Sienna, where he was appointed a senator, and architect and director of building construction. Between 1531 and 1535 he cast cannons and constructed fortification in both Parma and Venice. In 1536 he was offered a job in Rome and after some hesitation accepted the post of head of the papal foundry and director of papal munitions. It is not known when or where he died but there is documentary evidence that he was already dead on 30 April 1539.

His Pirotechnia was first published posthumously in Venice in 1540, it was printed by Venturino Roffinello, published by Curtio Navo and dedicated to Bernardino di Moncelesi da Salo. Bernardino is mentioned both in the book’s preface as well as in the text. The Pirotechnia consists of ten books, each one dealing with a separate theme in the world of Renaissance metallurgy, transitioning from the wining of metal ores, over their smelting to the use of the thus produced materials in the manufacture of metal objects and dealing with a whole host of side topic on the way. Although by no means as lavishly illustrated as De re metallica, the book contains 84 line drawings** that are as important in imparting knowledge of the sixteenth century practices as the text.

Book I, is titled Every Kind of Mineral in General, after a general introduction on the location of ores it goes on the deal separately with the ores of gold, silver, copper, lead, tin and iron and closes with the practice of making steel and of making brass.



Book II continues the theme with what Biringuccio calls the semi-minerals an extensive conglomeration of all sorts of things that we wouldn’t necessarily call minerals. Starting with quicksilver he moves on to sulphur then antimony, marcasite (which includes all the sulphide minerals with a metallic luster), vitriol, rock alum, arsenic, orpiment and realgar.



This is followed by common salt obtained from mine or water and various other salts in general then calamine Zaffre and manganese. The book now takes a sharp turn as Biringuccio deals with the loadstone and its various effects and virtues. His knowledge in obviously not first hand as he repeats the standard myths about loadstones losing their power and virtue in the presence of diamonds, goat’s milk and garlic juice. He now move on to, ochre, bole, emery, borax, azure and green azure. Pointing out that many of the things he has dealt with are rocks rather than metals he now introduces rock crystal and all important gems in general before closing the book with glass.


Book III covers the assaying and smelting metal ores concentring on silver, gold and copper.





Book IV continues with a related theme, the various methods for separating gold from silver.



Having covered separation of gold and silver Book V covers the alloys of gold, silver, copper, lead and tin.

Following the extraction of metals, their assays, separation and alloys, Book VI turns to practical uses of metals: the art of casting in general and particular.







Book VII the various methods of melting metals.







Having dealt with the casting of bells and cannons in Book VII, Book VIII deals the small art of casting.


Book IX is a bit of a mixed bag titled, Concerning the Procedure of Various Operations of Fire. The book opens with a very short chapter on alchemy. Biringuccio has already dealt with alchemical transmutation fairy extensively in Book I when discussing the production of gold. He doesn’t believe in it: These men [alchemists] in order to arrive at such a port have equipped their vessels with sails and hard-working oarsmen and have sailed with guiding stars, trying every possible course, and, finally submerged in the impossible (according to my belief) not one of them to my knowledge has yet come to port. In Book XI he acknowledges that although transmutation doesn’t work, alchemists have developed many positive things: …it is surely a fine occupation, since in addition to being very useful to human need and convenience, it gives birth every day to new and splendid effects such as the extraction of medicinal substances, colours and perfumes, and an infinite number of compositions of things. It is known that many arts have issued solely from it; indeed, without it or its means it would have been impossible for them ever to have been discovered by man except through divine revelation.The next chapter deal briefly with sublimation and very extensively with distillation both of which he acknowledges are products of the alchemists.




He now takes a sharp turn left with a chapter on Discourse and Advice on How to Operate a Mint Honestly and with Profit. This is followed with chapters on goldsmith, coppersmith, ironsmith and pewterer work, leading on to chapters on wire drawing, preparing gold for spinning, removing gold from silver and other gilded objects, and the extraction of every particle of gold and silver from slags of ore.



The book closes with making mirrors from bell metal and three chapters on working with clay.


Book X closes out Biringuccio’s deliberations with essays on making saltpetre and gunpowder, then moving on to the uses of gunpowder in gunnery, military mining, and fireworks, the later in both military and civil circumstances.



Biringuccio’s efforts proved successful with Italian editions of the book appearing in 1540 (Sienna), 1550 (Venetia), 1558/9 (Venegia), 1559 (Venetia), 1678 (Bologna), and 1914 (Barese). French editions appeard in 1556 (Paris), 1572 (Paris), 1627 (Rouen), and 1856 (Paris). A German edition appeared in 1925 (Braunschweig). There were only partial translation into English in 1555 (London) and 1560 (London). The first full English translation was made by Martha Teach Gnudi & Cyril Stanley Smith with notes and an introduction in 1941 (New Haven), which was republished by Dover Books in New York in 1990. It is the Dover edition that forms the basis of this blog post.

Biringuccio’s Pirotechnia is an important publication in the histories of technology, metallurgy, inorganic chemistry and the crafts and trades in general and deserves to be much better known.

**I have only chosen a selection of the drawings. On some subjects such as the use of bellows Biringuccio brings wholes rows of illustrations to demonstrate the diverse methods used.








Filed under History of Chemistry, History of Technology, Renaissance Science

How Chemistry came to its first journal – and a small-town professor to lasting prominence

Being fundamentally a lazy sod I am always very pleased to welcome a guest blogger to the Renaissance Mathematicus, because it means I don’t have to write anything to entertain the mob. Another reason why I am pleased to welcome my guest bloggers is because they are all better educated, better read and much more knowledgeable than I, as well as writing much better than I ever could, meaning I get princely entertained and educated by them. Todays new guest blogger, Anna Gielas, maintains the high standards of the Renaissance Mathematicus guests. Anna, who’s a German studying in Scotland whereas I’m an English man living in Germany, helps me to put together Whewell’s Gazette the #histSTM weekly links list. I’ll let her tell you somewhat more about herself.

 I’m a doctoral candidate at the University of St Andrews (Dr Aileen Fyfe and Prof Frank James from the Royal Institution of Great Britain are my supervisors) and I study the editorship and the establishment of early scientific journals in Britain and the German lands. I focus on the decades between 1760 and 1840 because this was the time when commercial (as opposed to society-based) science periodicals took off and became a central means of scientific communication and knowledge production

 As you can see Anna is an expert for the history of scientific journals and her post honours the 200th anniversary of the death Lorenz Crell, 7 June 1816, who edited and published the world’s first commercial journal devoted exclusively to chemistry. Read and enjoy.




In early February 1777, the famous Swiss physiologist Albrecht von Haller received a letter from an obscure small-town professor named Lorenz Crell. Crell had studied medicine, travelled Europe and returned to his hometown, where he succeeded his former professor of medicine at the local university.

The young professor asked Haller for feedback on a few essays he had submitted anonymously. Haller’s favourable comments encouraged Crell not only to reveal his name but also his risky plan: “I have a chemical journal in the works”, Crell announced to Haller in February 1777.

Lorenz Crell Source: Wikimedia Commons

Lorenz Crell
Source: Wikimedia Commons

The thirty-three year old professor had hardly any experiences with publishing, let alone with editing a learned journal. Yet his periodical would go on to become the first scientific journal devoted solely to chemical research—and would influence the course of chemical research throughout the German speaking lands.

In February of 1777—roughly one year before the inaugural issue of his Chemisches Journal appeared—things looked rather dire for Crell. At this time, there were essentially two professional groups in the German speaking lands devoted to chemical endeavours: university professors and apothecaries. The core of professorial work—and the task they were paid for—was teaching. And chemistry was taught as part of the medical curriculum. Apothecaries, in turn, focused mainly on producing remedies. Neither profession was based on chemical research. Experimentation would remain secondary until the nineteenth century.

So whom did Crell expect to pick up his periodical? He hoped to garner the attention of the eminent Andreas Sigismund Marggraf and his peers. Marggraf was the first salaried chemist at the Royal Prussian Academy of Sciences in Berlin. Like most of the leading chemical researchers, Marggraf was an apprenticed apothecary. He had audited lectures and seminars at the University of Halle, an epicentre of the Enlightenment, but he never graduated. Before taking on his post at the Academy, Marggraf earned his living through the apothecary shop that he had inherited from his father, the “Apotheke zum Bären” (Bear’s Pharmacy) on Spandauer Straße in Berlin.

Hoping that renowned chemical experimenters like Marggraf would pick up Crell’s journal was one thing—catching their attention and actually persuading them to contribute to the periodical a very different one. But Crell, it appears, had a plan. Later in 1777 he contacted Friedrich Nicolai, a famous publisher and bookseller of the German Enlightenment, and asked for the honour of reviewing a few chemical books for Nicolai’s Allgemeine deutsche Bibliothek (ADB). Crell picked a good moment to do so: in 1777, the ADB experienced record sales. But the editor-to-be approached Nicolai without any letter of introduction, which according to the mores of his times, the Prussian Aufklärer could have easily interpreted as impudence. Nicolai apparently saw moxie where others might have seen brazenness: the publisher commissioned reviews from Crell within days of receiving his letter. Within roughly two months, from November 1777 until mid-January 1778, Crell submitted no less than eleven pieces for Nicolai’s famous periodical. “I still owe you five reviews which shall follow quickly”, he wrote to the Prussian publisher in January. Nicolai received them by February.

Title page from the Chemisches Journal for 1778 Source: Wikimedia Commons

Title page from the Chemisches Journal for 1778
Source: Wikimedia Commons

Crell was aware that Nicolai had close ties to leading chemical investigators. The publisher was about to become an extraordinary member of the Prussian Academy of Sciences and chemical researchers such as Johann Christian Wiegleb and Johann Friedrich Gmelin contributed to the ADB. Wiegleb was a pharmacist who expanded his laboratory in Langensalza to teach chemistry. Wiegleb’s students lived, learned, and—most importantly—researched at his Privat-Institut. Johann Friedrich Göttling was one of Wiegleb’s pupils—as was the English industrialist Matthew Boulton.

Crell tried to tap into this network when he first contacted Nicolai. Maybe he even hoped to recruit the renowned chemical researchers for the inaugural issue of his Chemisches Journal. But the editor had to pace himself: the first issue of his periodical was almost entirely authored by himself and Johann Christian Dehne, a close friend and physician from a neighbouring village.

Ultimately, Crell’s concerted efforts as a regular contributor to the ADB and the editor of the Chemisches Journal paid off: all three—Wiegleb, Gmelin and Göttling—submitted articles for the second issue of Crell’s novel journal. Throughout the years many other joined them, including the Irish chemist Richard Kirwan, the Scottish researcher Joseph Black and the German Martin Heinrich Klaproth, the first professor of chemistry at the University of Berlin. Andreas Sigismund Marggraf, however, never published in Crell’s journal, maybe due to health issues following a stroke.

Crell devoted decades of his life to his journals. Within nearly 27 years he published nine periodicals, the longest-running and most famous of which is the Chemische Annalen (1784-1804). It was here that the German chemists debated (and death-bedded) phlogiston. During a busier year, such as 1785, Crell published over 2,000 pages of chemical facts, findings and flapdoodle.

Today, some scientists and historians belittle his role in chemistry, arguing that Crell did not contribute anything crucial to science. To judge Crell by what he did not achieve in his laboratory is to present science as a solitary undertaking, tucked away in labs. But if we acknowledge that science is a joint endeavour, based on communication, on-going exchange and discussions, Crell’s contribution appears vital.

According to the Berkeley-historian Karl Hufbauer, Crell’s Chemische Annalen was crucial in the formation of the German chemical community. Even more, Crell provided German and European researchers with an instrument for the production of chemical knowledge.

Today is the 200th anniversary of his death. Let’s use the date to commemorate all the editors throughout the centuries who spent countless hours at their desks—and contributed to the giant’s shoulders on which we stand today.




Filed under Early Scientific Publishing, History of Chemistry, History of science


DO IT! is the title of a book written by 1960s Yippie activist Jerry Rubin. In the 1970s when I worked in experimental theatre groups if somebody suggested doing something in a different way then the response was almost always, “Don’t talk about it, do it!” I get increasingly pissed off by people on Twitter or Facebook moaning and complaining about fairly trivial inaccuracies on Wikipedia. My inner response when I read such comments is, “Don’t talk about it, change it!” Recently Maria Popova of brainpickings posted the following on her tumblr, Explore:

The Wikipedia bio-panels for Marie Curie and Albert Einstein reveal the subtle ways in which our culture still perpetuates gender hierarchies in science. In addition to the considerably lengthier and more detailed panel for Einstein, note that Curie’s children are listed above her accolades, whereas the opposite order appears in the Einstein entry – all the more lamentable given that Curie is the recipient of two Nobel Prizes and Einstein of one.

How ironic given Einstein’s wonderful letter of assurance to a little girl who wanted to be a scientist but feared that her gender would hold her back. 

When I read this, announced in a tweet, my response was a slightly ruder version of “Don’t talk about it, change it!” Within minutes Kele Cable (@KeleCable) had, in response to my tweet, edited the Marie Curie bio-panel so that Curie’s children were now listed in the same place as Einstein’s. A couple of days I decided to take a closer look at the two bio-panels and assess Popova’s accusations.

Marie Curie c. 1920 Source Wikimedia Commons

Marie Curie c. 1920
Source Wikimedia Commons

The first difference that I discovered was that the title of Curie’s doctoral thesis was not listed as opposed to Einstein’s, which was. Five minutes on Google and two on Wikipedia and I had corrected this omission. Now I went into a detailed examination, as to why Einstein’s bio-panel was substantially longer than Curie’s. Was it implicit sexism as Popova was implying? The simple answer is no! Both bio-panels contain the same information but in various areas of their life that information was more extensive in Einstein’s life than in Curie’s. I will elucidate.

Albert Einstein during a lecture in Vienna in 1921 Source: Wikimedia Commons

Albert Einstein during a lecture in Vienna in 1921
Source: Wikimedia Commons

Under ‘Residences’ we have two for Curie and seven for Einstein. Albert moved around a bit more than Marie. Marie only had two ‘Citizenships’, Polish and French whereas Albert notched up six. Under ‘Fields’ both have two entries. Turning to ‘Institutions’ Marie managed five whereas Albert managed a grand total of twelve. Both had two alma maters. The doctoral details for both are equal although Marie has four doctoral students listed, whilst Albert has none. Under ‘Known’ for we again have a major difference, Marie is credited with radioactivity, Polonium and Radium, whereas the list for Albert has eleven different entries. Under ‘Influenced’ for Albert there are three names but none for Marie, which I feel is something that should be corrected by somebody who knows their way around nuclear chemistry, not my field. Both of them rack up seven entries under notable awards. Finally Marie had one spouse and two children, whereas Albert had two spouses and three children. In all of this I can’t for the life of me see any sexist bias.

Frankly I find Popova’s, all the more lamentable given that Curie is the recipient of two Nobel Prizes and Einstein of one, comment bizarre. Is the number of Nobel Prizes a scientist receives truly a measure of their significance? I personally think that Lise Meitner is at least as significant as Marie Curie, as a scientist, but, as is well known, she never won a Nobel Prize. Curie did indeed win two, one in physics and one in chemistry but they were both for two different aspects of the same research programme. Einstein only won one, for establishing one of the two great pillars of twentieth-century physics, the quantum theory. He also established the other great pillar, relativity theory, but famously didn’t win a Nobel for having done so. We really shouldn’t measure the significance of scientists’ roles in the evolution of their disciplines by the vagaries of the Nobel awards.



Filed under History of Chemistry, History of Physics, History of science, Ladies of Science

The Phlogiston Theory – Wonderfully wrong but fantastically fruitful

There is a type of supporter of gnu atheism and/or scientism who takes a very black and white attitude to the definition of science and also to the history of science. For these people, and there are surprisingly many of them, theories are either right, and thus scientific, and help the progress of science or wrong, and thus not scientific, and hinder that progress. Of course from the point of view of the historian this attitude or stand point is one than can only be regarded with incredulity, as our gnu atheist proponent of scientism dismisses geocentrism, the phlogiston theory and Lamarckism as false and thus to be dumped in the trash can of history whilst acclaiming Copernicus, Lavoisier and Darwin as gods of science who led as out the valley of ignorance into the sunshine of rational thought.

I have addressed this situation before on more than one occasion but as a historian of science I think that it’s a lesson that needs to be repeated at regular intervals. Because it is the American Chemical Society’s “National Chemistry Week 2015” I shall be re-examining the Phlogiston Theory whose creator Georg Ernst Stahl was born on 22 October 1659 in Ansbach, which is in Middle Franconia just down the road from where I live.


Georg Ernst Stahl (1660–1734) Source: Wikimedia Commons

Stahl had a fairly conventional career, studying medicine at Jena University from 1679 to 1684. 1687 he became court physician to the Duke of Sachen-Weimar and in 1694 he was appointed professor of medicine at the newly founded University of Halle, where he remained until 1715 when he became personal physician to Friedrich Wilhelm I, King of Prussia. Stahl like most chemists in the Early Modern Period was a professional physician, chemistry only existing within the academic context as a sub-discipline of medicine.

To understand the phlogiston theory we need to go back and take a brief look at the development of the theory of matter since the ancient Greeks. Empedocles introduced the famous four-element theory, Earth, Water, Air and Fire, in the fifth century BCE and this remained the basic theory in Europe until the Early Modern Period. In the ninth century CE Abu Mūsā Jābir ibn Hayyān added Sulphur and Mercury to the four-elements as principles, rather than substances, to explain the characteristics of the seven metals. In the sixteenth century CE, Paracelsus took over al- Jābir’s Sulphur and Mercury adding Salt as his tria prima to explain the characteristics of all matter. In the seventeenth century, when Paracelsus’ influence was at its height, many alchemists/chemists adopted a five-element theory – Earth, Water, Sulphur, Mercury and Salt – dropping air and fire. Robert Boyle, in his The Sceptical Chymist (1661), threw out both the Greek four-element theory and Paracelsus’ tria prima, groping towards a more modern concept of element. We now arrive at the origins of the phlogiston theory.

The German Johann Joachim Becher (1635–1682), a physician and alchemist, was a big fan of Boyle and his theories and even travelled to London to learn at the feet of the master.


Johann Joachim Becher (1635-1682) Source: Wikimedia Commons

Like Boyle he rejected both the Greek four-element theory and Paracelsus’ tria prima, in his Physica Subterranea (1667) replacing them with a two-element theory Earth and Water with Air present just as a mixing agent for the two. However he basically reintroduced Paracelsus’ tria prima in the form of three different types of Earth.

  • terra fluida or mercurial Earth giving material the characteristics, fluidity, fineness, fugacity, metallic appearance
  • terra pinguis or fatty Earth giving material the characteristics oily, sulphurous and flammable
  • terra lapidea glassy Earth, giving material the characteristic fusibility

Stahl took up Becher’s scheme of elements concentrating on his terra pinguis, making it his central substance and renaming it phlogiston. In his theory all substances, which are flammable contain phlogiston, which is given up when they burn, the combustion ceasing when the phlogiston is exhausted. The classic demonstration of this was the combustion of mercury, which turns to ash, in Stahl’s terminology (mercuric oxide in ours). If this ash is reheated with charcoal the phlogiston is restored (according to Stahl) and with it the mercury. (In our view the charcoal removes the oxygen restoring the mercury). In a complex series of experiment Stahl turned sulphuric acid into sulphur and back again, explaining the changes once again through the removal and return of phlogiston. Through extension Stahl, an excellent experimental chemist, was able to explain, what we now know as the redox reactions and the acid-base reactions, with his phlogiston theory based on experiment and empirical observation. Stahl’s phlogiston theory was thus the first empirically based ‘scientific’ explanation of a large part of the foundations of chemistry. It is a classic example of what Thomas Kuhn called a paradigm and Imre Lakatos a scientific research programme.

Viewed with hindsight the phlogiston theory is gloriously, wonderfully and absolutely wrong in all of its aspects thus leading to the scorn with which it is viewed by our gnu atheist proponent of scientism, however they are wrong to do so. I prefer Lakatos’ scientific research programme to Kuhn’s paradigm exactly because it describes the success of the phlogiston theory much better. For Lakatos it’s irrelevant whether a theory is right or wrong, what matters are its heuristics. A scientific research programme that produces new facts and phenomena that fit within the descriptive scope of the programme has a positive heuristic. One that produces new facts and phenomena that don’t fit has a negative heuristic. Scientific research programmes have both positive and negative heuristics simultaneously throughout their existences, so long as the positive heuristic outweighs the negative one the programme continues to be accepted. This was exactly the case with the phlogiston theory.

Most European eighteenth-century chemist accepted and worked within the framework of the phlogiston theory and produced a great deal of new important chemical knowledge. Most notable in this sense are the, mostly British, so-called pneumatic chemists. Working within the phlogiston theory Joseph Black (1728–1799), professor for medicine in Edinburgh, isolated and identified carbon dioxide whilst his doctoral student Daniel Rutherford (1749–1819) isolated and identified nitrogen. The Swede Carl Wilhelm Scheele (1742–1786) produced, identified and studied oxygen for which he doesn’t get the credit because although he was first, he delayed in publishing his results and was beaten to the punch by Joseph Priestley (1733–1804), who had independently also discovered oxygen labelling it erroneously dephlogisticated air. Priestley by far and away the greatest of the pneumatic chemists isolated and identified at least eight other gases as well as laying the foundations for the discovery of photosynthesis, perhaps his greatest achievement.

Henry Cavendish (1731–1810) isolated and identified hydrogen, which he thought for a time might actually be phlogiston, before going on to make the most important discovery within the framework of the phlogiston theory, the structure of water. By a series of careful experiments Cavendish was able to demonstrate that water was not an element but a compound consisting of two measures of phlogiston (hydrogen) with one of dephlogisticated air (oxygen). With the same level of precision he also demonstrated that normal air consists of four parts of nitrogen to one of oxygen or better said not quite. He constantly found something he couldn’t identify present in one one-hundredth and twentieth of the volume of nitrogen. In the nineteenth century this would finally be identified as the gas argon.

All of these discoveries are to be counted to the positive heuristic of the phlogiston theory. What weighed heavily on the negative side is the fact that as the accuracy of measurement increased in the eighteenth century it was discovered that the ashes, of mercury for example, left behind on burning were heavier than the original substance being burnt. This was troubling as combustion was supposed to be the release of phlogiston. Some supporters of the theory even suggested negative phlogiston to explain this anomaly. This suggestion, which never caught on, gets particularly mocked today, something I find somewhat strange in an age that has had to accept anti-matter and is now being asked to accept dark matter and dark energy to explain known anomalies in current theories.

Ironically it was the discoveries of oxygen and the composition of water that gave Lavoisier the necessary building blocks to dismantle the phlogiston theory and build his own competing theory, which would in the end prove successful and commit the phlogiston theory to the scrap heap of the history of chemistry. However one should never forget that it was exactly this theory that delivered him the tools he needed to do so. As I wrote in my sub-title even a theory that is wonderfully wrong can be fantastically fruitful and should be treated with respect when viewed with hindsight.



Filed under History of Chemistry, History of science, Myths of Science

A breath of fresh air

I’m supposed to be preparing a lecture on the eighteenth-century pneumatic chemists and I noticed this morning that today is the birthday of Stephen Hales who was responsible for a small invention that made pneumatic chemistry possible, so I decided to write a post about him.

Stephen Hales, aged 82, by J.McArdell after T. Hudson Source: Wikimedia Commons

Stephen Hales, aged 82, by J.McArdell after T. Hudson
Source: Wikimedia Commons

Hales, who is largely unknown today, except by experts, was regarded in the eighteenth century as one of the most important English natural historians with an international reputation amongst both natural historians and chemists. Born on the 17th September 1677 the tenth child and sixth son of Thomas Hales, heir to the Baronetcy of Beakesbourne and Brymore. As a younger son he was destined for the clergy and duly ordained in 1703 after graduating BA in 1700 at Corpus Christi College Cambridge. He obtained a fellowship in the same year and qualified MA in 1704. He remained in Cambridge until 1708 devoting his time to the study of the sciences mostly in tandem with William Stukeley, who would later become Newton’s physician. The two of them, being Cambridge men, studied Newton’s physics and astronomy as well as John Ray’s natural history.

Family connections found a curacy for Hales, which was the start of his long and successful church career, the high point of which was being appointed private chaplain to Princess Augusta, Dowager Princess of Wales and mother of George III in 1751. He was awarded a Doctor of Divinity by the University of Oxford in 1733 and is said to have turned down the offer of a canonry at Windsor from George II. Princess Augusta held him in such esteem that she had a monument erected to his memory in Westminster Abbey after his death in 1761, at the ripe old age of 83.

Stephen Hales monument Westminster Abbey Copyright: Westminster Abby

Stephen Hales monument Westminster Abbey
Copyright: Westminster Abby

However as stated above Hales was not only a successful pastor but also a very successful and important amateur natural historian making him an excellent example of the eighteenth- and nineteenth-century Anglican clergymen who devoted themselves to the study of the sciences making substantial advances to many fields. This historical phenomenon, of course, makes a mockery of the claims of the Gnu Atheists that religion and science are incompatible and that belief in God somehow hinders scientific thought.

Hales who became a member of the Royal Society in 1718 devoted his scientific studies to the circulatory systems of plants and animals. The results of his experimental studies on plants where published in his Vegetable Staticks. Hales determined the direction and force of sap flow in plants by inserting glass tubes into the stump of a vine with the branches cut off. He also inserted glass tubes containing water into the root systems of plants to determine the water absorption rate. Hales’ greatest achievement in his plant studies was to measure the transpiration rate. Through a series of complex and ingenious experiments he was able to determine how much water a plant perspired during its growing season and to demonstrate that this transpiration helped to draw water up through the roots.

Hales carries out similar experiments over many years on the circulatory systems of animals, which he published in his Haemastaticks in 1733. He later published both books together as his Statical Essays. Using the same method of inserting glass tubes into arteries and veins of various animals, Hales made the first ever blood pressure measurements. He then went on to measure cardiac output and compare pulse rates and blood pressure. These experiments were conducted on live animals without the benefits of sedation, which led his friend and neighbour, Alexander Pope, a dog lover, to condemn him for his cruelty to animals.

During his plant experiments Hales noted that air was expelled by his plants along with the water and he set out to devise methods to collect and measure the quantities of air thus produced. This is where Hales becomes interesting for the pneumatic chemists, who succeeded him in the eighteenth century and thus for my planned lecture. Hales devised a series of apparatuses to collect the air, which culminated in his invention of the pneumatic trough. A device that could be set to the general purpose of collecting gases separated from the generating apparatus.

Pneumatic Tr From Vegetable Staticks, opposite page 262 Source: Wikimedia Commons

Pneumatic Tr From Vegetable Staticks, opposite page 262
Source: Wikimedia Commons

The pneumatic trough would go on to be further developed by Henry Cavendish, William Brownrigg, Joseph Priestly and Antoine Lavoisier all of whom would use it in the discovery of various gasses, most notably hydrogen and oxygen; discoveries that would lead to the discovery of the composition of water and the beginnings of modern molecular chemistry. All of these researchers acknowledged their debt to Hales and his invention.

Throughout the late eighteenth century and the nineteenth century all of the great natural historians who laid the foundations of modern biology also acknowledge their debt to Hales for his pioneering work in both animal and plant physiology. It is only in the late nineteenth century that he began to be forgotten and to slide into obscurity; to become only the subject of study of specialist historians of science and no longer to be counted amongst the great natural historians.

As we have seen Hales was not just a brilliant theorist but also a very practical investigator designing and building complex experimental apparatus with which to conduct his researches. He applied this practical bent to the solution of an important social problem. His researches into air were a continuation of work begun in the seventeenth century by people such as Boyle and Hooke into air and its properties. One of the central concerns of these researches was the investigation of bad or foul airs, like those found in swamps, mines and enclosed spaces, such as prisons or ships. In fact Brownrigg’s development of Hales’ pneumatic trough was dedicated to this research. Hales was one of several researchers to invent a ventilator driven by bellows worked by hand and in larger versions by windmills to provide fresh air to enclosed spaces. Hales’ ventilators were a success and were widely employed in ships, prisons and mines.

Image of a Ventilation Bellows devised by Stephen Hales Source: Wellcome Library via Wikimedia Commons

Image of a Ventilation Bellows devised by Stephen Hales
Source: Wellcome Library via Wikimedia Commons

Addendum: 17 September 2020

Matthew Paskins on Facebook made the following important comment:

I think it’s an important part of Hales’ legacy that his celebrated ventilators were trialled by his contacts among slaveship owners, and that ventilation was advanced by supporters of slavery as a meliorist response to the conditions on board slaveships.

Hales is a classic example of those small scientific researchers, who upon investigation turn out not to be so small after all, who get lost and forgotten in our hagiographical presentation of the so-called giants of science. Next time you are at your doctors having your blood pressure checked spare a thought for the Reverend Stephen Hales the very first person to measure blood pressure.


Filed under History of Chemistry, History of medicine