C 238 ] 
generally fouud it to he between ^ and *. of the 
whole. 
Air thus diminifhed is not heavier, but rather 
lighter than common air; and though lime-water 
does not become turbid when it is expofed to this 
air, it is probably owing to the formation of a lelenitic 
fait, as was the cafe with the fimple burning of brim- 
fione abo vernen tioned . That fomething proceeding 
from the brimflone ftrongly affefts the water which 
is confined in the fame place with this brimflone, is 
manifeft from the very flrong 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 k in the other cafes, becaufe when this 
mixture is put into air which has been previoufly 
diminifhed, either by the burning of candles, by 
refpiration, or putrefaftion, though it never fails to 
diminifh 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 effeft. 
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 black, as it always 
becomes in a confined place ; but it prefently grew 
very hot, fmoaked copioufly, and fmelled very of- 
fenfively ; and when it was cold, it was brown, like 
the ruflof 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 A in its bulk ; but, as fir as 
I could 
