228 NICOLAUS STENO 



a fluid fall to the bottom of their own weight, whether the said 

 contents have been carried thither from some other where, or 

 have been secreted gradually from the particles of the fluid, 

 that too, either in the upper surface, or equally from all the par- 

 ticles of the fluid. Although a close relationship exists be- 

 tween crusts and sediments, they can nevertheless be distin- 

 guished easily because the upper surface of crusts is parallel to 

 the lower surface, however rough ^ this may be from various 

 larger projections, while the upper surface of sediments is paral- 

 lel to the horizon, or deviates but slightly therefrom. So in 

 rivers, the mineral layers, now green, now yellow, now reddish, 

 do not remove the unevenness of a stony bottom, while a sedi- 

 ment of sand or clay makes all level ; and it is due to this fact 

 p. 28. that in the formation of the different composite strata of the 

 earth I have easily distinguished crusts from sediments. 



Concerning the matter of the strata the following can be 

 affirmed : 



1 . If all the particles in a stony stratum are seen to be of the 

 same character, and fine, it can in no wise be denied that this 

 stratum was produced at the time of the creation from a fluid 

 which at that time covered all things ; and Descartes ^ also 

 accounts for the origin of the earth's strata in this way. 



2. If in a certain stratum the fragments of another stratum, 

 or the parts of animals and plants are found, it is certain that 

 the said stratum must not be reckoned among the strata which 

 settled down from the first fluid at the time of the creation. 



3. If in a certain stratum we discover traces of salt of the 

 sea, the remains of marine animals, the timbers of ships, and a 

 substance similar to the bottom of the sea, it is certain that the 

 sea was at one time in that place, whatever be the way it came 

 there, whether by an overflow of its own or by the upheaval of 

 mountains. 



4. If in a certain stratum we find a great abundance of rush, 

 grass, pine cones, trunks and branches of trees, and similar ob- 



1 aspera, Florentine edition, is an error for asperae. 



^ The reference is to Descartes, Principia Philosophiae (first edition Amsterdam, 1644), 

 Pars Quarta, XXXII ff. See QLuvres de Descartes^ PublUes par Charles Adam et Paul 

 Tannery, Paris, Vol. VIII (1905), p. 220 ff. 



