Page:Scientific Memoirs, Vol. 1 (1837).djvu/383

Rh From the experiments made by several philosophers we are enabled to calculate the values corresponding to the boiling point of $$k$$ and $$\frac$$, for different liquids; we can therefore deduce from them the corresponding values of $$\frac$$.

These results confirm, in a striking manner, the theory that we are explaining; they show that $$C$$ is slowly augmented with the temperature, as has been already stated: we have seen that for $$t = o$$, $$\frac = 1.41$$, whence $$C = 0.7092$$; this result is deduced from experiments upon the velocity of sound.

We here find, starting from experiments upon the vapour of water, for $$t = 100^\circ$$, $$ \frac = 1.115$$, whence $$C = 0.8969$$; $$C$$ is therefore increased from 0 at 100° to $$0.187$$, which gives as the mean of the differential coefficient between these two limits The mean of the two experiments performed by MM. De Laroche and Bérard gives us, between the limits $$22^\circ\centerdot83$$ and $$96 \centerdot 90$$, for the mean value of $$\frac$$ the quantity $$0.002565$$.

These two results differ little from each other, and their divergence will be sufficiently explained, by reflecting on the number and the variety of the experiments whence the data on which they are founded are derived.