extracted from different Kinds of Waters. 439 
periments have {hewn me that water in general abforbs 
about twice as much of dephlogifticated as of common 
air; for which reafon, I think, that the refpirable air of 
Seine water is rather lefs than that of di failed water. 
Accordingly I have found, that Seine water, after it has 
been boiled for a long time, abforbs in forty days about 
one fourteenth of its own bulk of dephlogifticated air, 
when in the fame length of time it does not abforb more 
than one twenty-eighth of common air. This feems to 
be an experiment of very great confequence, and is much 
worth notice; efpecially as it difcovers a new charadteriftic 
by which dephlogifticated air may be diftinguilhed from 
common air; and {hews, that water abforbs a greater 
quantity of thofe kinds of air, which contain a lefs quan- 
tity of pblogifton. 
It mult however be obferved, that it is impoffible to 
determine exactly the quantity of air that is extracted 
from veflels filled with water, by means of fire; becaufe 
% 
a portion of the air is ablorbed by the water of the tub 
in the a£t of its coming forth. It will certainly be more 
exadt to receive the air in veflels immerfed in quickfil- 
ver; but then there are many other inconveniencies to 
encounter. 
It may be almoft fuperfluous to mention, that the 
above related experiments are very ufeful in explaining 
M m m 2 the 
