The Seashell on the Mountaintop

I just finished reading The Seashell on the Mountaintop, the Swedish version. Picked it up as a cheap pocket book and I was pleasantly surprised. The book was a fascinating read and showed many of the troubles scientists faced during 17th century, both political and religious.

The story involves Nicholas Steno, born in Denmark as Niels Stensen and starts when he has just finished his anatomy studies. Being exceptionally skilled with the scalpel, Steno is the first to discover the saliva glands and the tear canal and his public dissections are quickly becoming famous events. He travels all over Europe, through Amsterdam, Paris, Florence and Hannover, spending most of his time working at the then famous Accademia del Cimento in Florence. The academy was funded by the brothers Ferdinando II and Leopoldo de Medici and was the first one focusing solely on "experimental philosophy".

After years of thinking about the problem of seashells being found inside rocks and mountains everywhere Steno figured out the final piece in the puzzle. By carefully studying layers of rocks in hills of Tuscany he realized that sediments in water were deposited at the bottom with the largest particles first and then smaller and smaller particles on top. Steno concluded that the layers and strata in the cliffs and mountains had been deposited in the same way with the newest layers in the direction of the smaller particles above the bigger ones. He also suggested that the seashells inside were real seashells from the sea, not growing inside the rock. He realized the significance of being able to tell the age of the layers of rock apart and opened the way to study the ancient history of Earth.

In 1669 he published his findings in a short booklet called De solido intra solidum naturaliter contento dissertationis prodromus, that translated means Preliminary discourse to a dissertation on a solid body naturally contained within a solid. This was the first published study of geology performed in a completely scientific way that included the previously ignored time dimension that's so clearly embedded in the rock layers.

The rest of the book describes how Steno continues his studies of sediments and mountains, but also his increasing devotion to Catholicism eventually earning him the title of bishop. The book is well written and I could not put it down until I finished reading the last page.

Something that surprises me with the book is the amount of famous scientists and philosophers that Steno meets. He becomes friends or colleagues with such celebrities as Baruch Spinoza, Giovanni Borelli, the contemporary members of The Royal Society of London, Gottfried Leibniz and many more. Opinions and observations concerning Stenos interests in anatomy and geology made by thinkers like Descartes, Da Vinci and even earlier Aristotle is also included in the book.

Even if the world feels a lot smaller now with easy communication and quick traveling across the globe, it's still inspiring to see how people have always liked to travel and exchange ideas. The Seashell on the Mountaintop made history feel more vibrant to me than it has in a long time.