i8o Mr. Cavf-Kdish*s E^iperiments oh Air. 



It may be worth remarking, that whereas hi the detonation 

 of nitre with inflammable fubrtances, the acid unites to plUo- 

 gidon, and forms phlogifticated air, in thefe experiments the 

 reverfe of this procefs was carried on ; namely, the phlogiftl- 

 cated air united to the dephlogiilicatt- d air, wliich is equivalent 

 to being deprived of its phlogiflon, and was reduced to nitrous 



acid. 



In the above-mentioned Paper I alfo gave my reafons for 

 thinking, that the fmall quantity of nitrous acid, produced bjr 

 the explofion of dephlogifticated and inflammable air, pro- 

 ceedcd from a portion of phlogifticated air mixed with the de- 

 phlogifticated, which I fuppofed was deprived of its phlogifton, 

 and turned into nitrous acid, by the adlion of the dtplilogifti- 

 cated air on it, airilled by the heat of the explofion. Thii 

 opinion, as mufl: appear to every one, is confirmed in a re- 

 markable, manner by the foregoing experiments ; as from thera 

 it is evident, that dephlogifticated air is able to deprive phlo- 

 gifticated air of its phlogiflon, and reduce it into acid, when 

 affirted by the electric fpark ; and therefore it is not extraordi- 

 nary that it fhould do fo, when aflifted by the heat of the 

 explofion. 



The foap-lees ufed in the foregoing experiments were made 

 from lalt of tartar, prepared without nitre ; and were of fuch 

 a firength as to yield one-tenth of their weight of nitre when 

 faturated with nitrous acid. The dephloglfticated air alfo was 

 prepared without nitre, that ufed in t'le firfl experiment with 

 the foap-lees being procured from the black powder formed by 

 the agitstion-:of-quickfilver mixed with Iead% and that ufed 



^* This aif vvjtsf as pure as any that can be procured by moil proceiTes. 1 pro* 

 pofe giving an accouctt of the experiment, in which it was prepared, in a future 

 Paiper^ij-;:.^-- , . 



it) 



