ACID IN THE ATMOSPHERE. 13 
the residue of lime water is poured out, and its 
reduced value is then ascertained, as it was be- 
fore, by means of some test acid of a known 
strength, thus data are gained for the calcula- 
- tion of the carbonic acid engaged to the lime. 
In my investigations of this subject I have 
adopted Mr. Dalton’s mode, and from December 
1828 to 1830 the experiments have been made 
in a glass bottle of a balloon shape, of the capa- 
city of 471 cubic inches, fitted with a brass cap 
and stop cock for the purpose. 
The experiments of the present year (1830) 
have been made in a larger bottle of the capaci- 
ty of 498 cubic inches. The method of filling 
the latter bottle with air was a little different 
from that of the former, for instead of filling 
the bottle with rain water, as was the case with 
the first bottle, to get the air in, the end of a 
bellows pipe was introduced into the latter and 
the air blown in. 
December 20th. 1828. 
XP RE Men NE 2, 
The balloon shaped bottle was filled with air 
from Cornbrook, and 20z. measures of lime wa- 
