[3] The original Latin manuscript of De solidorum elementis was written circa 1630 by Descartes; reviewer Marjorie Senechal calls it "the first general treatment of polyhedra", Descartes' only work in this area, and unfinished, with its statements disordered and some incorrect.
[4] It turned up in Stockholm in Descartes' estate after his death in 1650, was soaked for three days in the Seine when the ship carrying it back to Paris was wrecked, and survived long enough for Gottfried Wilhelm Leibniz to copy it in 1676 before disappearing for good.
[2][5] In De solidorum elementis, Descartes states (without proof) Descartes' theorem on total angular defect, a discrete version of the Gauss–Bonnet theorem according to which the angular defects of the vertices of a convex polyhedron (the amount by which the angles at that vertex fall short of the
relating the numbers of vertices, edges, and faces of a convex polyhedron from Descartes' theorem,[2] and De solidorum elementis also includes a formula more closely resembling Euler's relating the number of vertices, faces, and plane angles of a polyhedron.
[2][7] Reviewer F. A. Sherk, after noting the obvious relevance of Descartes on Polyhedra to historians of mathematics, recommends it as well to geometers and to amateur mathematicians.
He writes that it provides a good introduction to some important topics in the mathematics of polyhedra, makes an interesting connection to number theory, and is easily readable without much background knowledge.