Arialyfts of the Atr. 17 9 
Tartar, made with nitre and tartar, and 
mixed with a double quantity of calx of 
bones, yielded in diftillation 112 cubicle 
inches of air; that is, 224 times its bulk of 
air, which 112 cubick inches weighing 32 
grains, is nearly j part of the weight of 
the SalTartar. There is a more intenfc de- 
gree of heat required to raife the air from 
Sal Tartar than from nitre. 
Hence we fee, that the proportion of 
air in equal bulks of SalTartar and nitre is 
as 224 to I 80. But weight for weight, nine 
contains a little more air in it, than this 
Sal Tartar made with nitre. But Sal Tartar 
made without nitr^", has probably a little more 
air in it than this had, becaufe it is found 
to make a greater explofion in the Tulvis 
FulminanSy than the nitrated Sal Tartar, Buc 
fuppofing, as is found by this Experiment, 
that Sal Tartar^ according to its fpccifick gra- 
vity, contains part more in it than nitre ; 
yet this excefs of air is not fufficient to 
account for the vaftly greater explofion of 
SalTartar than of nitre ; which feems prin- 
cipally, to arife from the more fixt nature 
of Sal Tartar ; which therefore requires a 
more intenfc degree of fire, to feparatethe 
N 2 air 
