extracted front different Kinds of Waters. 43 5 
obtained fome air which feemed not fenfibly diminifhed 
when fhaken in water. Having introduced one meafure 
and 37 parts of this air into the tube ufed to try the di- 
minutions, it gave with the nitrons air I-*- 19, I + 48', 
when the fame quantity of nitrous and atmofpheric air 
gave II+26, 11 + 6: it is- therefore certain, that the air 
extracted from Seine water is purer than common air. 
Another time I extracted, in the fame manner, and 
from the fame water, the air; one meafure and 24 parts 
of which being introduced into the tube-, &c. and fhaken > 
was reduced to one meafure —31 parts, that is, one fifth 
of it was abforbed. Treated with the nitrous air it gave 
I— 4, when equal meafures of common and nitrous- air 
gave I±o : it was therefore better than common air. 
A third time I extracted the air, in the manner above 
mentioned, from the water of the river Seine, contained 
in three mattrafies ; this air was about one twenty-eighth 
of the bulk of the water,, and it gave with the teft of ni- 
trous air II— 14, II— 9, III— 9 ; when the common air 
mixed with nitrous air, as ufual, gave II— 14, II +8; 
III + 8. It is therefore clear, that the air extracted -from 
the Seine water, by the adtion of fire in glafs veffelsj is. 
much better than common air, or than the air which is- 
extracted from the fame water when boiled in tin veflels 4 
Another. 
