Nicolaus Steno

Nicolaus Steno , Latinized form of Niels Stensen , 1638-86, Danish anatomist, geologist, and Roman Catholic prelate. He lived principally in Copenhagen, Paris, and Florence. He investigated the heart, brain, muscles, and glands and discovered (1661) the excretory duct (duct of Steno) of the parotid gland (one of the pairs of salivary glands). He pointed out the true origin of geological strata and of fossils and recorded his studies of crystallization. He was converted from Lutheranism to Roman Catholicism in 1667, became a priest in 1675, and vicar apostolic in N Europe in 1677. In his devotion to missionary work he virtually abandoned science. His Earliest Geological Treatise (1667) was translated and edited by Axel Garboe (1960).

Bibliography: See study by A. Cutler (2003).

Steno, Nicolaus (1638–86) A Dane of great intellect, Neils Stensen (1638–1686) had studied in Copenhagen and Leiden before entering the service of the Medici in Florence and had acquired a formidable reputation as an anatomist. In 1666 he was presented with the head of a giant shark for dissection and noted the similarity of the teeth to fossil sharks' teeth from rocks near by. From this Steno, as he was now known, hit upon the concept of fossils as preserved organic remains. He also began to travel about Tuscany looking at strata and collecting fossils. His commitment to geology overtook his many other interests and he produced a summary volume describing the origins of fossils, the implications of fossil marine shells in strata in the Tuscan hills, and a few other geological phenomena. This, his Prodromus (1669), was to herald a major work on geology, and it led Steno to sense the conflict between Genesis and his own careful observations. He was able to formulate what amounted to the law of stratal superposition. The formation of mineral deposits and metalliferous vein ores in recognizable crystalline forms took his attention and were carefully described in scientific fashion.

Nevertheless, he was converted to Catholicism, and incidentally calculated that Noah's flood took place about 4000 years ago. The Dissertation forecast in the Prodromus was never finished. Steno recognized that mountains may be formed by volcanic activity and by erosion, and that collapse into subterranean cavities may cause faulting. He clearly had some idea of the way in which geological processes gave rise to different landscapes.

Steno eventually took holy orders, was appointed a bishop, and spent the remainder of his life in peripatetic poverty.

D. L. Dineley