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that it acquired a remarkably acid and aftringent 

 tafte from it. The fmell of water thus impreg- 

 nated is at firft peculiarly pungent. I did not 

 chufe to fwallow any of it, though, for any thing 

 that I know, it may be perfectly innocent, and 

 perhaps, in fome cafes, falutary. 



This kind of air is retained very obftinately by 

 water. In an exhaufted receiver a quantity of 

 water thus faturated emitted a whitifh fume, fuch 

 as fometimes ifiues from bubbles of this air when 

 it is firft generated, a\nd alfo fome air bubbles? 

 but though it was fuffered to ftand a long time 

 in this fituation, it ftill retained its peculiar tafte ; 

 but when it had flood all night pretty near the 

 fire, the water was become quite vapid, and had 

 depofited a filmy kind of matter, of which I had 

 often collected a confiderable quantity from the 

 trough in which jars containing this air had 

 flood. This I fuppofe to be a precipitate of the 

 metal by the folution of which the nitrous air was 

 generated. I have not given fo much attention to it 

 as to know, with certainty, in what circumftances 

 this depofit is made, any more than I do the mat* 

 ter depofited from inflammable air abovementioned ; 

 for I cannot get it, at leaft in any confiderable 

 quantity, when I pleafe ; whereas I have often 

 found abundance of it, when I did not expect it 

 at all. 



The nitrous air with which I made the firft im- 

 pregnation of water was extracted from copper ; but 

 when I made the impregnation with air from quick- 

 filver, the water had the very fame tafte, though 

 the matter depofited from it feemed to be of a dif- 



•F f i ferent 



