E 16 J 
again fuppofe, that the nitrous air 
employed was fo weak, that, inftead 
of three meafures, fix were required. 
before the faturation was fully com- 
pleated, and that. thus the remain- 
ing column of air in. the great tube 
occupies 608, inftead of 308, fub- 
divifions ; we fhall find that, the re- 
fult will be juft the fame; that is 
to. ) fay, that, by. fubtracting the 608 
; ‘parts remaining from the 800. parts 
of both airs employed in the expe-. 
riment, there will be found ex= 
adtly 192 fub-divifions.deftroyed 3 
and that thus in: both cafes the ac- 
curate falubrity of the air is afcer- 
tained. If. fuch bad. nitrous, aif 
was only at. hand as was juit now 
fuppofed, it. follows, that-a longer 
tube ought to be employed. ee 
7 This obfervation, which I owe 
< ieee to Abbé, Fontana, is in my 
= 7 — 
sin 
