LIFE AND WORKS OF NICOLAUS STENO XXVII 



produced by the collapsing of deeper layers — e. g. through the in* 

 fluence of water and fire — beneath the upper layers, which then have 

 shared in the collapse; or by the raising of deeper layers — e. g. by 

 volcanic eruptions — which at the same time have raised the layers 

 above them. Thus he also accounts for the occurrence of layers cons 

 taining marine animals far above the present surface of the sea. — As 

 the basis of his theory Steno had only the observations, which he had had 

 the opportunity of making in Tuscany when travelling about the coun* 

 try in the company of the Grand*Duke, and although Tuscany is 

 especially favourable for observations of this sort, we can not but admire 

 him for having found the time to make such a number of excellent 

 observations as he did, but also more especially for the way in which, 

 from out of his knowledge of such a very small part of the entire surface 

 of the Earth, he was able to make generalizations applicable to the 

 whole of the globe. Steno's explanation of the formation and the oc* 

 currence of the fossils, as well as ot the nature and position of the va* 

 rious strata, is the one still in force in our own days ; for after having 

 fallen into oblivion for more than a century its position was established 

 in the beginning of the nineteenth century, especially through Elie de 

 Beaumont, who translated great parts of Steno's book, thus showing 

 how tar he had reached, even at such an early date. There are two 

 points, however, in the history of the formation of the Earth, in which 

 Steno's knowledge is decidedly behind that of our time. Firstly, with 

 regard to the changes which in the process of time have taken place 

 in the surface of the Earth, where — for external as well as for internal 

 reasons— he had to keep within that limited space of some few thousand 

 years, which according to the doctrine of the Church had elapsed 

 since the creation of the world, for which reason he had to prove, what 

 appears to have given him some trouble, that all the changes in the 

 surface of the Earth can have taken place during that short space of 

 time. Secondly, he had to let all changes be occasioned by violent re* 

 volutions in nature, partly to bring them within such a limited space 

 of time, partly because, with the knowledge of those days, he could 

 have no idea of the changes slowly and daily taking place in the sur* 

 face of the Earth, and of the immense effects of these changes through 

 exceedingly long periods. 



Steno's examination of bodies found in the earth was, as the very title 

 of his book suggests, not limited to the remains of animal and vegetable 

 life, that is fossils, but comprised all solid bodies, which in nature 

 occur inclosed within other solid bodies, and thus he was also led to 

 the study of crystals. Even scientists who had especially devoted their 

 time to the investigation of crystals and their occurrence, as for in* 

 stance Steno's friend Montanari, were of opinion that crystals still were 

 being formed in the cavities of rocks, having a vegetative growth, and 



