2i8 NICOLAUS STENO 



The few points set forth above suffice for the solution of all 

 the doubtful issues in our inquiry, and I have desired to sum 

 them up now in the three following propositions : 



I 



If a solid body is enclosed on all sides by another solid body, 

 of the two bodies that one first became hard which, in the 

 mutual contact, expresses on its own surface the properties of 

 the other surface. Hence it follows : 



1. That in the case of those solids, whether of earth, or rock, 

 which enclose on all sides and contain crystals, selenites, mar- 

 casites,^ plants and their parts, bones and the shells of animals, 

 and other bodies of this kind which are possessed of a smooth 

 surface, these same bodies had already become hard at the time 

 when the matter of the earth and rock containing them was 

 still fluid. And not only did the earth and rock not produce 

 the bodies contained in them, but they did not even exist as 



P. 16. such when those bodies were produced in them. 



2. That if a crystal is enclosed in part by a crystal, a selenite 

 by a selenite, a marcasite by a marcasite, those contained 

 bodies had already become hard when a part of the containing 

 bodies was still fluid. 



3. That in the earth and rock in which crystalline and petri- 

 fied shells, veins of marble, of lapis lazuli, silver, mercury, anti- 

 mony, cinnabar, copper, and other minerals of this kind are 

 contained, the containing bodies had already become hard at 

 the time when the matter of the contained bodies was still 

 fluid ; and that, consequently, the marcasites were produced 

 first, then the stones in which the marcasites are enclosed, and, 

 finally, the veins of minerals which fill the fissures of the rock. 



II 



If a solid substance is in every way like another solid sub- 

 stance, not only as regards the conditions of surface, but also 

 as regards the inner arrangement of parts and particles, it will 

 also be like it as regards the manner and place of production, 

 if you except those conditions of place which are found time 



^ By the term " crystals," Steno means mineral quartz (cf. p. 237) ; selenUes refers to crys- 

 tals of gypsum, and marcasites to pyrites (cf. p. 225, n. i). 



