STENO, NICOLAUS (1631-1686), Danish naturalist, was born at Copenhagen in 1631, and studied medicine and anatomy in that city and in Paris. After a period of travel he settled in Italy (1666) at first as professor of anatomy at Padua, and then in Florence as house-physician to the grand-duke Ferdinand II. of Tuscany. He returned to his native city in 1672 to become professor of anatomy, but, having become a Roman Catholic, he found it expedient to return to Florence, and was ultimately made apostolic vicar of Lower Saxony. He died at Schwerin in Mecklenburg, on the 25th of November 1686. His fame rests on De solido intra solidum natwaliter contento, published at Florence in 1669. In this notable work Steno described various gems, minerals and petrifactions (fossils) enclosed within solid rocks. He compared the fossil with the living organisms, and distinguished marine and fluviatile formations. He argued also in favour of the original horizontality of sedimentary deposits.
See Di Nicola Stenone e dei suoi sludii geologici in Italia, by G. Capellini (1870); K. A. von Zittel's History of Geology and Palaeontology (Eng. ed., 1901) ; and VV. J. Sollas, in Science Progress for Jan. 1898.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)