Quantity of Carbon in carbonic Acid. 283 
The precipitate in lime water from the gas produced in the 
combustion of diamond, appeared to us denser than that from 
the combustion of charcoal. 
In order to see how far the weight of the precipitate of car- 
bonate of lime would agreee with the results of the foregoing 
experiments, we drew off 20,5 cubic inches of the gas which 
had been thus altered by the combustion of diamond in the 
last experiment by the register H, and received it in bottles 
over mercury ; then admitting lime water, we obtained a co- 
pious precipitate of carbonate of lime, which being dried at the 
temperature of 212 0 Fahrenheit, weighed 12 grains. 
But as the 20,5 cubic inches require the same corrections to 
bring them to the mean temperature and pressure ; we say, 
as the actual volume of all the gas is to its correction, so is 
the quantity drawn oft' to that which it would have been at 
the mean : 
49,84 : 51,20 : : 20,50 : 21,06, the volume after the corrections 
were made. 
Then, to find how much carbonic acid was contained in these 
21,06 cubic inches, we state it thus : As the total quantity of 
gas after the experiment is to the total weight of carbonic acid 
gas found by calculation, so is the quantity of gas experimented 
upon to the weight of carbonic acid gas which it ought to have 
contained, 
51,20 : 13,91 : : 21,06 : 5,72 grains. 
Every 100 grains of precipitated carbonate of lime contain 
44 grains of carbonic acid ; 1 2 grains were procured in our 
experiment. 100 : 44 : : 12 : 5,28 
Therefore the carbonic acid contained in our precipitate of 12 
grains weighed 5,28; by calculation it should have weighed 
