STENO

Steno Nicolaus. Born: Copenhagen, Denmark, 10 January 1631; Died: Schwerin, Mecklenburg, Germany, 25 November 1687.
Steno (or non–Latinized Stensen) attended the University of Copenhagen from 1656 to 1660. He then went on to Amsterdam, but received an M.D. in absentia from the University of Leiden in 1664. Steno became professor of anatomy at the University of Padua in Italy. He was also appointed house physician to Grand Duke Ferdinand II of Tuscany. During this decade, the greater part of Steno’s available time was taken up by his studies of human anatomy, geology and catholism. This is also the period when his greatest contributions to science were written. In 1672, he returned for a time to Denmark, but came back to Italy in 1674. Ordained a priest in the Roman Catholic Church in 1675, Steno devoted the remainder of his life to the church in a progression of appointments. Steno ended his life as a bishop in Numster, Germany.

His most important mineralogy book is ‘De Solido Intra Soldvm Natvraliter Contento, Dissertationis Prodromvs’ (The Prodromous To A Dissertation Concerning Solids Naturally Con–
tained within Solids. Laying a Foundation for the Ren dering a Rational Accompt both of
the Frame and the several Changes of the Masse of the Earth, as also of the various Productions
in the same)

This book is the most important contribution to mineralogy and geology made during the seventeenth century. Within this volume, intended as an introduction to a much larger never published work, Steno while studying quartz observes for the first time the fundamental crystallographic law of constancy of interfacial angles, which was confirmed and generalized over
a century later with the invention in 1783 of the contact goniometer by Arnould Carangeot Steno was also the first to recognize the principle of superposition that states sedimentary rocks were originally laid down horizontally, while non–horizontally results from strata being deformed by later forces. As an integral concept within this principle, the author realized that the oldest strata were the first to be formed and that overlying stratum must have been deposited at later times. If this were not enough “firsts” for one book, the Prodromus was also important in the history of paleontology, as it was among the earliest publications to attribute fossils to be the petrified remnants of animals and plants.
The plate were the observations on crystals are pictured, was originally created as a large double
plate, half engraved and half printed. However, due to its large size it is common to find it bound into the book as two plates.