59^ Dr. Daubenyo/j a certain Kind of 



formerly examined the mucous matter deposited by the waters 

 of Valdieri in Piedmont, — a thermal spring containing sulphu- 

 retted hydrogen, — and that he fully satisfied himself, as to the 

 whole being derived from bodies that once possessed organiza- 

 tion, having traced the different stages of decomposition and 

 change exhibited by the several parts of the same deposit, from 

 a structure completely analogous to that of a Conferva^ to a 

 gelatinous mass in which no distinction of parts was visible. 



It has been remarked, indeed, by Anglada, Gimbernat, and 

 others who have noticed this phaenomenon, that a portion of the 

 substance in question is chemically dissolved in these waters ; 

 and although 1 cannot admit the proposition as a general truth, 

 yet I have myself found, that the thermal waters of Aix in Savoy, 

 and those of Chaudes-aigues in the department of Cantal in 

 France, even when carefully filtered and completely transpa- 

 rent, begin to exhibit traces of a substance of this kind as soon 

 as they are concentrated. 



But this only proves, that the mucous matter derived from 

 such sources is soluble in water*, and that the growth of these 

 bodies takes place, not only in the reservoirs which receive the 

 water after it has escaped from the earth, but also in the sub- 

 terranean canals through which it finds its way in reaching the 

 surface ; — a notion which will be admitted without difficulty, 

 when we reflect upon the luxuriant growth of many species 

 belonging to the lower tribes of animals and vegetables in spots 

 equally secluded from light and the external air. Neither, if 

 the substance called zoogene by Gimbernat agree in its charac- 

 ters with this product of the Pyrenean waters, (and I am in- 

 duced to suspect that it does, from his enumerating Aix in 

 Savoy as one of the spots in which he found it,) need we 



* During the process of evaporation it seems to undergo some chemical change ; 

 for it is no longer soluble in water, when once separated from it. 



be 



