708 Col. roy’s Experiments for 
comprehended between freezing and boiling, or 0.7 8 6 1 3 
for each degree. The maximum ftill correfponds to the 
fpace between 52 0 and 72 0 ; and the minimum is con- 
ftantly at the boiling point. 
From thefe three laft experiments it would feem, that 
the particles of air may be fo far removed from each 
other, by the diminution of preflure, as to lofe a very 
great part of their elaftic force ; fince, in the ninth ex- 
periment, the heat of boiling water applied for an hour 
together, could only make it occupy a fpace which, com- 
pared with what it filled at freezing, bears the propor- 
tion of 1 141.5 to 1000. 
From the third clafs of experiments it appears, that 
common air, prefled with a Angle atmofphere, whether 
taken into the manometer in its natural ftate, or heated 
red-hot therein, has the fame expanfion with air of only 
five-fixths of that denfity: for 1000 equal parts of this 
air expanded 484.21 from 212 0 of heat, whereof the 
mean rate is 2.28401 for each degree. By comparing 
this refult with that of the firft clafs, and again with that 
deduced from the fecond fet of the fecond clafs, it would 
feem, that the elaftic force of common air is greater than 
when its denfity is confiderably augmented or dimi- 
niftxed by an addition to, or fubtraftion from, the weight 
6 with 
