APPENDIX. 319 
greatly increafe the efFervefcenc Vibrations of 
the Particles, while others as much retard 
them : But as we cannot pry into the various 
Pofition of thefe Particles, in their feveral 
Combinations, on which their different Ef. 
feds depend, fo it will be difficult to account 
I from any Principle, even though a trrue one, 
from the very different EfFedls of effervefcent 
Mixtures. 
S>i- He further obferves, that Bodies are 
“ fometimes diflblved more by effervefcent 
Menffruums in vacuo than in the Air : As 
Lead is when thus mixed with Spirit of 
“ Salt. And Filings of Iron mixed in the 
fame in Number 15. As alfo Tutti with 
Spirit of Nitre Number ^5. 
‘‘ 5^2. Yet Bodies are often more diflblved 
by a Menftruum in the open Air, than in 
“ vacuo., as Braff in Aquafortis. 
5)5. He obferves alfo, that there are fre- 
quently generated in Effervefcences, either in 
the Air or in vacuo elaftic Vapours, which 
arc like Air ; and are doubtlels true perma- 
nent Air, for I have kept fome of ihefe thus 
generated Airs by me for fix Years 5 after 
which, on comprefling them in a condenf- 
ing Engine, in the fame manner as is menti- 
oned 
