2 04 Anahjfis of the Air. 
So that the 8 5 cubick inches of air, Experi- 
ment 9(5, which I found upon meafuring was 
abforbed by the Walton mineral and com- 
pound Aqua-fortis^‘'^zs the excefs of what 
was abforbed by thofe fumes above what 
was generated by the fermenting mixture. 
And the reafon is the fame in filings of 
Iron and Spirit of Nitre, Experiment 94, 
which alfo abforbed more than they generat- 
ed, whether wither without water : The rea- 
fon of which will appear prefently. 
Hence alfo we fee the reafon why filings 
of Iron and compound Aqua fortis in the 
fame 94 Experiment abforbed air •, and why 
when mixed with an equal quantity of water 
it moftly abforbed, but did fometimes gene- 
rate, and then abforb again : And it was the 
fame with Oil of Vitriol, filings of Iron and 
Water, and New^caJlleQozl and compound 
Aquafortis and others : viz. At firft, when 
the ferment was brisk, the abforbing fumes 
rofe fafteft, whereby more air was abforbed 
than generated ; but as the ferment abated, to 
•fuch a degree as to be able ftill to generate 
elaftick air, but not to fend forth a propor- 
tionable quantity of fumes, in that cafe more 
air would be generated than abforbed. 
And 
