L-tor | 
little practice foon be convinced, 
that by this method the degree of 
falabrity of any air may be afcer- 
tained with as much exactnefs as 
the degree of heat and cold by the 
thermometer of Reaumur; for the 
es Sarg of the refult will fearce _ 
exceed —t. of the two airs employed, 
and it would be difficult to ade 
upon the thermometer of Reaumur 
of -of a degree of his fcale, 
~ “Though [have for the mott part 
made all my experiments accor ing 
to the prefent method of Mr. Fon- 
ay, as I was not in poffeffion of a 
ube long cnough to put the various 
airs to the teft, according to the ori- 
inal method of the Rev. Dr. Prieit- 
Jey, with as much accuracy aS I» 
could have | withed, yet Te made Ze 
great many trials in a Way not effen- 
ually different from his, by letting Z = z 
NZ oe 
