262 NICOLAUS STENO 



being produced, whether this took place after the manner of 

 other plants, or in the fashion of the mercury tree, the substance 

 of the stone had not yet laid aside the character of a fluid ; this 

 fact, again, is further assured not only by the softer consistency 

 of the stone, but also by the angular bodies common in the den- 

 p. 67. drite of Elba, such as form only in a free fluid. But what need 

 is there of other proofs, when experience itself speaks ? I have 

 seen various moist places, not only those exposed to the sun, 

 but also underground, where, on account of water flowing by, a 

 rock growing to moss and other plants was being covered with 

 new moss of a different kind. 



Hitherto I have reviewed the principal bodies whose place 

 of finding has for many afforded no clue to the place of their 

 production ; and at the same time I have hinted how, from that 

 which is perceived, a definite conclusion is formed in regard to 

 that which cannot be perceived. 



THE DIFFERENT CHANGES WHICH HAVE TAKEN PLACE IN TUSCANY 



In what way the present condition of any thing discloses the 

 past condition of the same thing, is above all other places 

 clearly manifest in Tuscany ; inequalities of surface observed in 

 its appearance to-day contain within themselves plain tokens of 

 different changes, and these I shall review in inverse order, 

 proceeding from the last to the first. 



1. At one time the inclined plane A [PL XI, fig. 20] was 

 in the same plane with the higher, horizontal plane B, and the 

 end of the same plane A thus raised, as also the end of the 

 higher, horizontal plane C, were continuous, whether the lower, 

 horizontal plane D was in the same plane with the higher hori- 

 zontal planes B, C, or another solid body existed there, support- 

 ing the exposed sides of the higher planes. Or, what is the 

 same thing, in the place where to-day rivers, swamps, sunken 

 plains, steeps, and planes inclined between sand hills are seen, 



p. es. all was once level, and at that time all the waters, both of rains 

 and of springs, were flooding that plain, or had opened for 

 , themselves underground channels beneath it; at any rate, there 

 were cavities under the upper strata. 



2. At the time when the plane B, A, C [PI, XI, fig. 21] 



