When and how geology became a science.

The next statement in this post could well loose me several of my British readers I’m not a big fan of The Infinite Monkey Cage, BBC Radio 4’s comedy science programme. I don’t particularly like the puerile schoolboy humour favoured by the hosts. I was not partial to it when I was a puerile schoolboy and have grown less fond of it over the years. However on Monday I had some time to kill before going out for the evening and didn’t feel like reading, so I thought I would listen to the latest episode, which promised, amongst other things, a discussion of when and how geology became a science.

After several minutes of banter geologist Hermione Cockburn was asked exactly that.  The first problem that occurred to me was that there was no discussion or explanation either of what science is or more importantly what it means for a discipline to become a science. Now I know that both of these questions are much too complex to be handled in a thirty minutes comedy programme, which of course raises the question of the legitimacy of trying to discuss geology becoming a science in the same context. This problematic did not seem to phase Ms Cockburn who blithely answered that the transition occurred through the work of James Hutton or, she went on, maybe through that of Charles Lyell. This prompted the question from the hosts, why it had taken so long after Newton and the emergence of modern science for this to occur. Now Newton died in 1727 and Hutton was born in 1726 so the separation in time wasn’t that great.

The answer provided to the supposed time gap was of course religious prejudice. After a surprisingly positive account of Ussher’s chronology the other expert guest in the programme, paleobiologist David Martill, went on to explain that although the Greeks had realised that fossils were the remains of animals this knowledge had got lost in the Dark Ages (he actually used this term!) and it wasn’t until the seventeen hundreds that anybody looked at fossils correctly. Now at this point I began to ask myself, not for the first time, if the BBC is going to discuss history of science, in this case history of geology, why don’t they get a historian of science, in this case historian of geology, who knows what they are talking about to do the job?

Now I’m neither a geologist nor a historian of geology but even I know that the answer provided here by the experts are, at very best, highly dubious and at the worst totally wrong. I did ask myself, if Ms Cockburn was indulging in a bit of local patriotism, as James Hutton was a graduate of Edinburg University, the institution where she is employed. Just staying in the eighteenth century, if Hutton is doing scientific geology then so were his biggest intellectual opponent the German geologist Abraham Gottlob Werner, who was his contemporary and the French polymath Georges-Louis Leclerc, Comte de Buffon who preceded them both. Less well known is the fact that Leibniz, who died in 1716, wrote and published definitely scientific papers on geology in his capacity as inspector of mines for his employer, the Elector of Hanover, George I of England.

Of course scientific geology didn’t begin in the eighteenth century. Assuming that scientific means theories based on empirical evidence then the sixteenth century German physician Georg Pawer (modern German spelling Bauer i.e. farmer), better known as Agricola, produced scientific geology in his books on mining. The most famous of which is his De re metallica, published posthumously in 1556.  Another sixteenth century polymath who produced scientific writings on geology based on excellent empirical observations was Leonardo da Vinci but who, as usual, did not publish his findings and so can’t really be counted amongst the scientific geologists.

However the person I most missed in this misconstrued mini-history of geology is one of my favourite seventeenth century polymaths Niels Stensen (1638–1686), better known by the short form of his Latinised nom de plume simply as Steno.

Born in Copenhagen of Lutheran Protestant parents, why this is relevant will become clear later, Steno entered the University of Copenhagen to study medicine at the age of nineteen. He studied under Thomas Bartholin, discoverer of the lymphatic system, whose younger brother Rasmus Bartholin first discovered double refraction the phenomenon that led Huygens to formulate his wave theory of light. Bartholin urged Steno, on completion of his medical degree, to travel to Amsterdam to study under Gerard Blasius, where after six months he moved on to Leiden to become part of one of the most extraordinary constellations of medical talent assembled in one place in the seventeenth century. Under the direction of the professors Franciscus Sylvius and Johannes van Horne Jan Swammerdam, Reinier de Graaf, Frederick Ruysch and Steno were busy revolutionising the study of human anatomy. All of them made major contributions and discoveries.

During this period the strangest story involving Steno concerned the discovery of the function of the ovaries. De Graaf claimed this discovery for himself but Swammerdam was convinced that the laurels should go to van Horne and himself. After the two, now ex-friends, had argued bitterly on who should be awarded the priority Swammerdam appealed to the Royal Society in London to arbitrate in the matter and pass judgement. After due consideration of the various claims the Royal Society announced Steno as the winner although he had never claimed the priority.

After further medical work in Paris Steno went to Northern Italy where he was first professor of anatomy in Pisa and then private physician to Ferdinando II de’Medici thus becoming de facto a member of, Ferdinand’s brother, Leopoldo de’Medici’s Accademia del Cimento.  During his time in Tuscany Steno turned to his second scientific career, geology.

Steno was given a shark’s head by Ferdinando, which being an anatomist he proceeded to dissect. He realised that the shark’s teeth resembled glossopetrae or “tongue stones” and hypothesised that these were in fact fossilised shark’s teeth. This led him to more general conclusions about the organic origins of fossils, which he published in his De solido intra solidum naturaliter contento dissertationis prodromus, or Preliminary discourse to a dissertation on a solid body naturally contained within a solid in 1669. This was not Steno only contribution to the history of geology. During his walks along the coast he observed the layers visible in the rock formations around him and developed the three fundamental laws of stratification – the law of superposition, the principle of original horizontality and the principle of lateral continuity – which he published in his Dissertationis prodromus of 1669.

Around this time Steno’s career took another major turn. In 1667 our Danish Lutheran converted to Catholicism. In 1675, having abandoned science completely, he was ordained a priest and in 1677 he was consecrated titular bishop of Titiopolis. Steno left Italy for Northern Germany where he worked as a missionary trying to convert the Lutherans back to Catholicism. He rejected all his worldly goods living as a pauper, a live style that led to his death in 1686. Steno was nominated for sainthood by his parishioners and although he was beatified he was never canonised.

To return to the history of geology Steno was not alone in the latter part of the seventeenth century in suggesting an organic theory of fossils with both Robert Hooke and John Ray propagating similar ideas.

If you want to know more about the history of geology then I can strongly recommend the blog of David Bressan at Scientific American and suggest you start with this post that explains more about the contributions of Agricola, Leonardo and Steno.