1 94 Analyfis of the Air. 



Houjhold, forne calculi humani, I made the 

 following Experiments with them, which I 

 fhall here infert, viz. 



I diftilled a calculus in the iron retort 

 (Fig. 38.) 5 it weighed 230 grains, it was 

 fomething lefs in bulk than | of a cubicle 

 inch : There arofe from it very briskly, in 

 diftillation, 5i6cub:ck inches of elaftick air, 

 that is, a bulk equal to 645 times the bulk 

 of the ftone ; fo that above half the ftone 

 was raifed by the action of the fire into ela- 

 ftick air y which is a much greater propor- 

 tion of air than I have ever obtained by 

 fire from any other fubftances, whether ani- 

 mal, vegetable or mineral. The remaining 

 calx weighed 49 grains, that is, ^rH part 

 of the calculus -, which is nearly the fame 

 proportion of calx, that the worthy Dr. Slan 

 found remaining, afcer the diftilling and cal- 

 cining two ounces of calculus', " one ouna 

 " and three drams of which (he fays) eva- 

 " porated in the open fire, (a material cir- 

 <c cumftance, which the chymifts rarely ih 

 u quire after) of which we have no account.' 

 Pbilof. Tranfatf. Lo^thorf s Abridgment, Vol 

 III. p. 179. The greateft part of which was 

 we fee by the prefent Experiment, railed int< 

 permanently elaftick air. 



