- [ 20S ] 



generally found it to be between £ and i. of the 

 whole. 



Air thus diminh'hed is not heavier, but rather 

 lighter than common air ; and though lime-water 

 does net become turbid when it is expofed to this 

 air, it is probably owing to the formation of a felenitic 

 fait, as was the cafe with the Ample burning of brim- 

 ft one abovementioned. That fomething proceeding 

 from the brimftone ftrongly affecls the water which 

 is confined in the fame place with this brimftone, is 

 manifeft from the very ftrong fmell that it has of the 

 volatile fpirit of vitriol. I conclude the diminution 

 of air by this procefs is of the fame kind with the 

 diminution of it in the other cafes, becaufe when this 

 mixture is put into air which has been previoufljf 

 diminh'hed* either by the burning of candles, by 

 iefpiration, or putrefaction, though it never fails to 

 diminish it fomething more, it is, however, no far- 

 ther than this procefs alone would have done it. 

 If a frefh mixture be introduced into a quantity of 

 air which had been reduced by a former mixture, 

 it has little or no farther effect. 



I obferved, that when a mixture of this kind was 

 taken out of a quantity of air in which a candle had 

 before burned out, and in which it had flood for fe- 

 veral days* it was quite cold and blacky as it always 

 becomes in a confined place ; but it prefently grew 

 very hot, fmoaked copioufly> and fmelled very of* 

 feniwely ; and when it was cold, it was brown, like 

 the ruft of iron. 



I once put a mixture of this kind to a quantity of 

 •inflammable air, made from iron, by which means 

 it was diminifhed ^ or r V in its bulk; but, as far as 



1 could 



