0-8 Mr. Cavkndi^h''s Experiments on Air. 



pifticated ; and therefore I tried whether nitre, much phlogiflr- 

 cated, would precipitate lilver from its folution. For this pur- 

 pofe I expofed feme nitre to the fire, in an earthen retort, till it 

 had yielded a gocd deal of dephlogiilicated air; and then,hav- 

 ins: diflblved it in water, and added to it fome well purified 

 fpirit of nitre till it was fenfibly acid, in order to be certain 



4. " 



that the alkali did not predominate, I dropped into it fom© 

 folution of filver, which immediately made a very copious pre- 

 cinitate. This folution, however, being deprived of fome of 

 its phlogifl:on by evaporation to drynefs, and expofure for a feW 

 weeks to the air, lofl: the property of precipitating lilver from 

 its folution ; a proof that this property depeiided only on its- 

 phlogiftication, and not on its having abforbed fea-falt from 

 the retort, or by any other means. 



Hence it is certain, that nitre, when m-uch phlogiflicated, is-: 

 capable of making a precipitate with a folution of filver; and 

 therefore there is no reafon to think, that the precipitate^ 

 which our fait occafioned with a folution of filver, proceeded 

 from any other caufe than that of its being phlogifticated j. 

 efpecially as it appeared by the fmell, both on firil: taking it 

 out of the tube, and on the addition of the fpirit of nirre,' 

 previous to dropping in the folution of filver, that the acid in 

 it was much phlogifticated. This property of phlogiflicated 

 nitre is w^orth the attention of chemifts ; as otherwife they may 

 fometimes be led into^ miffakes, in iuvefligating the prefence of 

 marine acid by a folution of filver. 



In the above-mentioned Paper I faid, that when nitre is deto- 

 nated with charcoal, the acid is converted into phlogifticated 

 air ; that is, into a fubffan<:e which^ as far as I could perceive^ - 

 pofTefTes all the properties of the phlogiffcicated air of our at- 

 mofphere ; from which I concluded; that phlogifficated air i& 

 5 , jiothing. 



