32 
Proceedings of Boyal Soeiety of Edinhirgh. [sess. 
On the Foundations of the Kinetic Theory of Gases. 
V. By Professor Tait. 
{Ahstract.) 
(Read January 18 and February 15, 1892.) 
The first instalment of this part of my paper deals mainly with 
the theory of the behaviour of mixtures of CO^ and N, for which 
some remarkable experimental results were given by Andrews about 
1874. His full paper, so far as he had drawn it up for press, was 
published posthumously in the PMl. Trans, for 1886, and is re- 
printed in his Scientific Papers, Ho. L. One special reason for the 
introduction of this question at the present stage of my work was 
the desire to attempt a correction of Amagat’s numbers, for the 
(very small) admixture of air with his CO 2 . The virial equation 
for a mixture is formed on the same general principle as that I 
employed for a single gas. There are, of course, more undetermined 
constants : — and, unfortunately, the data for their determination are 
barely adequate. The general results, however, agree in character 
with those described by Andrews : — the particular phenomenon 
which is most closely studied being the increase of volume, at con- 
stant pressure, when the gases (originally separated by the liquefac- 
tion of one) were allowed to diffuse into one another. 
Since Part lY. of this paper was printed, M. Amagat has pub- 
lished ifdomptes Rendus, October 12, 1891) additional data of a 
most valuable character bearing on the isothermals of CO 2 : — 
especially the very important isothermal of 32° C. ; and he has 
given the pressure of the saturated vapour at 0°, 10°, 20°, and 
30° C. I have endeavoured to utilize these, as far as possible, not 
only for my present main object : — the examination of the relation 
between temperature and kinetic energy : — but also, incidentally, 
for the determination of the latent heat of the saturated vapour 
at various temperatures, and the relative densities of the liquid 
and vapour when in equilibrium. These data have also enabled 
me to obtain more exact approximations to the values of the 
