Dr. Austin s Experiments on 
the meafure : I have therefore generally been contented to ufe 
fractional numbers, and have been ftudious only to introduce 
fuch quantities of the airs as were convenient for the expe- 
riments. 
The inflammable air ufed in all thefe experiments was ob- 
tained from foliated tartar. I have alfo paflTed eledtric lparks 
through inflammable air from pit- coal, and found that it 
expanded in the fame manner. Dr. Biggin's * has (hewn, that 
5,5 of inflammable air from foliated tartar inflamed with 7,5 of 
dephlogifticated air, form 5 meafures of fixed air. Dr. Priest- 
ley -j- has deduced nearly the fame proportions of the dephlo- 
gifiicated and fixed airs, by combining the dephlogifticated and 
inflammable airs in a condenfed ftate. In the following com- 
buftions of thefe airs, after accounting for the phlogifticated air 
in the refidues, the quantity of fixed air produced feems to be 
equal in bulk to the inflammable air combined ; and the 
dephlogifticated air to be to the fixed air, or to the inflamma- 
ble, in the ratio of 7 to 5 ; or, in other words, when 5 
meafures of fixed air are formed, it appears, that very 
nearly 5 of inflammable air and 7 of dephlogifticated air have 
difappeared. But in burning different airs there will be con- 
ftant variations in the refults, arifing from the very different 
ftates of the heavy inflammable air ; and therefore, in thefe 
observations, I am obliged to follow the proportions which 
took place in my own experiments. 
Exp. 2. Three meafures and one-third of inflammable air were 
expanded to 5I : the difference is 2^. To this air were added 
3 1 meafures of dephlogifticated air, which increafed the column 
of air to 9 meafures. One eledlrical fipark reduced them to 4, 
# Higgins on Acetous Acid, p, 288, 289. 
f Priestley, Vol. VI. p. 27. 
2 
Lime 
