6 
ON CHEMISTRY. 
thus been acted upon by the same solvent, and for almost precisely 
the same time, but in different positions for determining results. 
The parcel in the basin or flask has lost as great a quantity of elastic 
fluid, as that in the phial, but neither the bulk nor the weight of that 
fluid (which is Carbonic acid) can be ascertained; whereas the 
parcel in the phial, provided the operator have been careful to main¬ 
tain the same position of both phials and their balancing weights, is 
placed in a situation wherein the loss will be readily discovered. The 
two phials being now weighed again, will be found to have lost 
weight, and, therefore, small weights must be added to the scale with 
the phials, till it slightly preponderate; and then by counting the 
number of grains so added, the operator will detect, precisely, the 
quantity of elastic acid which has passed off 
The reader, will, I think, be at no loss to pursue the directions 
thus detailed, without let or perplexity, and may then turn to the 
consideration of the results. 
Perhaps so little action has been induced in the basin , that it has 
scarcely been perceptible; and in the phial, there has been hardly 
any loss of weight. One parcel will have been a correcting check to 
the other, and so far the student have found a source of satisfaction, 
but another result, and one far more important, remains to be men¬ 
tioned. In passing, I remark that this inaction, and scarcely sen¬ 
sible loss of weight, combine to prove that little calcareous matter has 
been in the soil; that point is settled. But 1 will let it pass, for it 
best suits my purpose to presume that several grains of elastic fluid 
have escaped. 
Lime exists in soils in a state of Carbonate, that is, in union with 
carbonic acid ; but its affinity for that acid, is less than for muriatic 
acid. When, therefore, the latter is placed in contact with it, the 
former is abandoned, and escapes in the state of gas, leaving the lime 
united with the stronger acid, in the form of a liquid muriate of lime. 
In order to determine the quantity of carbonate of lime, the weight 
of the gas lost must be carefully examined : it is rather unfortunate 
that chemists differ in their calculations. Henry estimates the car¬ 
bonic acid in every hundred parts, to be about 35 parts, others state 
it at 39 ; Davy says, “ Carbonate of lime in all its states contains a 
determinate proportion of carbonic acid, i. e. nearly 43 per cent:—and 
for every 4i grains of elastic gas loss, he estimates the carbonate of 
lime to be 10 grains. We will in this case suppose that, the experi¬ 
ment with the two phials, has produced a diminution in weight, of 6 
grains; the quantity, therefore, of Carbonate of lime, in the 180 grains 
left after drying, &c. is about 15 grains. To correct this experiment 
