Miscellaneous. 



429 



whence they were deposited appears to have been in a very troubled 

 state, just as it is in the present day when in a hot vessel. Now, 

 when in this hot state it could not absorb or retain in solution car- 

 bonic acid from the air. Only in those spots where local causes 

 had reduced the heat, carbonic acid might be dissolved and car- 

 bonate of lime formed; or, if pre-existing, brought into solution, 

 and afterwards deposited. This heated state of the ocean might, in 

 some degree, account for its saline impregnation. There is no evi- 

 dence of land having existed during the primary period, and during 

 the ages which constituted it, this heated water acting upon the rocks 

 which formed the crust of the globe, would have a wonderful effect in 

 promoting chemical combinations, and dissolving the various soluble 

 materials contained in these rocks. In all strata of later origin than 

 the primary, we find rock salt. Salt springs arise from the coal sys- 

 tem : — Rock salt abounds in the new red sandstone. The Alpine 

 salt works are in the oolitic system ; those of Cardona in the green- 

 sand ; and of Wieliczka in the tertiary rocks. (Phillips.) But, as far 

 as I am aware, rock salt is absent from the primary strata. This 

 seems to indicate that the water had not obtained its full saline im- 

 pregnation when those strata were deposited. And indeed, it seems 

 not improbable, that during this era, the water obtained many of its 

 soluble salts from the disintegration of the primary rocks. 



But to return from our digression. The existence of the limestones 

 proves that even in the primary period, carbonic acid existed. The 

 peculiar smell which distinguishes hornblende, and various aluminous 

 minerals, when they are moistened, is due to minute traces of ammonia 

 contained in them. Now this smell is very perceptibly possessed by 

 the hornblende schists, and accompany gneiss; and hence we have a 

 right to conclude, that they absorbed this compound from the air, or 

 from the water, during their deposition. There are many facts to 

 prove that ammonia was formerly of inorganic origin. Not only is 

 it a constituent of all aluminous and ferruginous minerals, but it 

 exists in many natural products found in volcanic regions. Dr. 

 Daubeny has supposed that ail the carbonic acid and ammonia which 

 now exists, or has existed in the atmosphere, may have been derived 

 from the interior of the earth. He finds a difficulty in conceiving how 

 the hydrogen and nitrogen could have been made to unite on the sur- 

 face of the globe, and hence, draws them from its interior. But al- 

 though we do not agree as to the source from whence the food of 

 plants is derived, we both equally admit that the primary food was 

 of inorganic origin. 



