on the Absorption of Air by Water. 171 



of the retort became hot, and no doubt gave out a little air ; 

 but not much ; because as soon as the water in the retort 

 began to boil briskly, the water in the throat and beak was 

 driven out by the steam, and never boiled at all. Thus, 

 it appears that 100 cubic inches of Clyde water contain 

 3*113 cubic inches of air. 



The experiment being repeated in precisely the same 

 way, the product of air was so nearly the same that it 

 seems unnecessary to state the particulars minutely. 



II. — Composition of the Air thus extracted. 



I let up 100 volumes of this air into a small jar, filled 

 with water and standing over the water-trough, and put 

 into it a stick of phosphorus of such a length that it reached 

 from the bottom to the top of the jar, and traversed all the 

 air. In 24 hours the bulk of this air was reduced to 71*48 

 volumes of azotic gas. Hence, the air extricated from the 

 water was composed of 



71*48 volumes of azotic, and 

 28*52 volumes of oxygen gas. 

 The air extricated during the second experiment, analyzed 

 in the same way, was composed of 



70*32 volumes of azotic, and 

 29*68 volumes of oxygen gas. 



If we take the mean of these two analyses, we get the 

 constituents of the air extracted from Clyde water by 

 boiling as follows : 



Volumes of azotic gas . . . 70*9 

 Volumes of oxygen gas . . . 29* 1 



100*0 



III. — Alteration produced on this Air when left standing on 

 the water-trough. 



1. The 5*26 cubic inches of air extracted by boiling water 

 from the Clyde, were put into a small cylindrical glass 

 capable of holding 1 1 cubic inches, and left inverted over 

 the water trough. Every 24 hours 1 cubic inch (or 100 

 volumes) of this air was taken out, and left till next day 

 witli a stick of phosphorus passing through it. The 



