FREE AND PERFECTLY ELASTIC MOLECULES IN A STATE OF MOTION. 67 
its essential mode of reaction; and do not they even demand of us a ready assent to 
its all-prevailing influence in the phenomena of Nature ? 
Although the utmost caution in adopting any hypothesis is the proper accompani¬ 
ment of a sober spirit of inquiry, it does not appear inconsistent with such a spirit to 
advocate the trial of these principles as a foundation for mathematical research in the 
several departments of molecular physics. 
It is the matured conviction of the writer that upon such foundation we shall have 
to build if we are destined ever to become acquainted with the secret mechanism of 
Nature. Would that his feeble voice could call attention to the subject, could direct 
upon it some portion of the vast mathematical talent that this country can now, more 
than at any former period, boast of. 
J. J. W. 
k 2 
