182 JMiscellanies. 
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 ina state of solution, and not ina 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 these 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 
