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the particles of a fait, may augment its bulk, with- 
out fenfiblv increafing its weight. Yet the two 
following experiments rather tend to diminish the 
probability of this opinion. 
Experiment V. 
I took water which had been well purged from its 
air by long boiling, and which had been corked up 
whilft it was warm ; when it had acquired a proper 
temperature, 1 filled a matrafs with it, as before, 
and putting into it fal gemmae, &c. I obferved that the 
elevation before folution was the fame as when com- 
mon water was ufed, and that it funk equally in the 
neck during the folution ; but then the reparation of 
air feemed greatly lefs in all the trials I made. This 
pbaenomenon is ealily explained : common water is 
always faturated with air ; upon the addition of any 
fair, the particles of water begin to attrad: and 
diffolve the fait, and let go the air with which they 
are united; this air, added to the air contained in the 
fait, renders the whole much more vifiblein common 
than in boiled water. Mufichenbrook and others 
are of opinion, that air only fills the interfaces of 
water, without augmenting its bulk; they ground 
their opinion upon obferving that the fpecific gravi- 
ties of common water and of water purged from its 
air are equal ; the fad, taking it for granted, will 
fcarcely authorize the conclufion : for, fuppofing that 
a cubic inch of common water contains even a cubic 
inch of air, the difference of the weight of the water 
when faturated with air, and when freed as much as 
pofilble from it (though probably it can never be 
wholly 
