182 Miscellanies. 



and under the same atmospheric influences, and he found that in one 

 hundred grains of the ashes of the cresses, watered by pure water, 

 there were twelve grains of sulphate of potash, and twenty grains of 

 carbonate of potash ; while that in one hundred grains of the ashes 

 of the cresses, watered by the water of sulphate of lime there were 

 eighteen grains of sulphate of potash, and thirty grains of carbonate 

 of lime. M. Peschier afterwards submitted the remainder of the 

 cresses, already watered by the water of sulphate of lime, to the con- 

 tinued action of an electric current during many days, after which he 

 found that the ashes of these cresses included twenty six per cent of 

 sulphate of potash. M. Peschier made similar experiments upon 

 lucerne or Spanish trefoil, and he observes " the sulphate of lime 

 ought to be made use of in a state of solution, and not in a solid 

 state;" he concludes from it that the sulphate of lime does not, in 

 times of drought, act by communicating to the plant its water of crys- 

 tallization ; water, which it will re-absorb in a time of moisture, but that 

 its principal action is considerably to augment the proportion of the 

 sulphate and of the carbonate of potash, in the organization of veg- 

 etables. But here a question arises. Some earths are found in veg- 

 etables, as is proved incontestably ; but do these earths make a part 

 of their proper nourishment. Physiologists appear not to agree upon 

 this subject. The experiments of Saussure tend to prove the con- 

 trary. 



This observer has analized the ashes of two trees of the pinus abies 

 (spruce) the one growing upon a granitic, the other upon a calcareous 

 soil. In one hundred parts of the first he found thirty parts of silex, 

 and fifteen of alumine, and forty eight of carbonate of lime. In one 

 hundred parts of the second he found thirty parts of alumine, and six- 

 ty three of carbonate of lime. 



It seems thence to result, that the silex was not necessary to 

 the development of ihese trees, and that in the first experiment its 

 presence was purely adventitious, and resulted from the qualities of 

 the soil in which the tree had grown. Experiments carefully made 

 will probably give a similar result for other trees, and we would so- 

 licit, for the sake of agriculturalists who need accurate information, 

 whether it be correct to say that unassimilated inorganic mineral sub- 

 stances can strictly be said to enter into the organization of a living 

 system like that of vegetables. It is obvious from the experiment of 

 M. Peschier, that he introduced, at will, into the cresses, by means 

 of water, containing sulphate of lime in solution, one third more of 



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