C 484 3 
XXIX. On the existence of a limit to vaporization . By M. 
Faraday, F. R. S. Corresponding Member of the Royal 
Academy of Sciences at Paris , &c. &c. Communicated 
May 26, 182 6 . 
Read June 15, 1826. 
It is well known that within the limits recognised by expe- 
riment, the constitution of vapour* in contact with the body 
from which it rises, is such, that its tension increases with 
increased temperature, and diminishes with diminished tempe- 
rature ; and, though in the latter case we can, with many 
substances, so far attenuate the vapour as soon to make its 
presence inappreciable to our tests, yet an opinion is very 
prevalent, and I believe general, that still small portions are 
produced ; the tension being correspondent to the compara- 
tively low temperature of the substance. Upon this view, it 
has been supposed that every substance in vacuo or sur- 
rounded by vapour or gas, having no chemical action upon 
it, has an atmosphere of its own around it ; and that our 
atmosphere must contain, diffused through it, minute portions 
of the vapours of all those substances with which it is in 
contact, even down to the earths and metals. I believe that 
a theory of meteorites has been formed upon this opinion. 
Perhaps the point has never been distinctly considered ; 
* By the term vapour, I mean throughout this paper that state of a body in which 
it is permanently and indefinitely elastic. 
f See Sir H. Davy’s paper on Electrical Phenomena exhibited in Vacuo. Phil. 
Trans, mdcccxxii. p. 70. 
