1 94 Analyfis of the Air . 
Houljhold, fome calculi humanly I made the 
following Experiments with them, which I 
fhall here infert, viz. 
I diftilled a calculus in the iron retort 
(Pig. 38.) it weighed 230 grains, it was 
fomething lefs in bulk than ^ of a cubick 
inch : There arofe from it very briskly, in 
diftillation, 5 1 6 cubick inches of elaftick air, 
that is, a bulk equal to 645 times the bulk 
of the Stone ; fo that above half the Stone 
was raifed by the a&ion of the fire into elaf- 
tick air ; which is a much greater propor- 
tion of air than I have ever obtained by 
fire from any other fubftances, whether a- 
nimal, vegetable or mineral. The remaining 
calx weighed 49 grains, that is, ~~ 9 part 
of the calculus 5 which is nearly the fame 
proportion of calx, that the worthy Dr. 
Slave found remaining, after the diftilling 
and calcining two ounces of calculus , “ one 
cc ounce and three drams of which (he 
fays) te evaporated in the open fire (a mate- 
cc rial circumftance, which the Chymifts 
“ rarely enquire after) of which we have no 
“ account. ” *Philof. TranfaEl. Lowthorp’s 
Abridgment, Vol. III. p. 179. The greateft 
part of which was, we fee by the prefent 
Experiment, raifed into permanently elaftick 
air. 4 
