66 
MR. J. J. WATERSTON ON THE PHYSICS OF MEDIA COMPOSED OF 
motion. We see further that 0 3 As expresses the constitution of one volume of this 
acid, and referring to As, No. 7, we find that its specific heat in the solid form is 
nearly 4 times greater than it ought to be in the vapour. 
The probable general inference is that such molecules consist of several parts, more 
or less free to move independently of each other, and that when they escape from the 
bonds of liquid cohesion and become free projectiles, these parts can no longer assume 
vis viva of their own, but are in subjection to the impressed condition of their common 
centre of gravity. 
The great question in this department is, Do such compound bodies which have so 
great a specific heat in the solid form have it all at once reduced in so vast a 
proportion when raised to vapour ? This interesting point, as remarked at length in 
Note B, has yet to be determined by an experiment made on the specific heat of 
sulphuric ether vapour, as being the most accessible, which, if these views are correct, 
ought to be only about -g-th of the specific heat of the liquid. 
Column No. 5 contains the quotient of the gaseous specific gravity by the specific 
gravity of the liquid or solid, and represents the relative size of the molecules. The 
subject of atomic volume has recently been the subject of interesting discussion by 
M. Kopp (‘Ann. de Chim.,’ vol. 75, 1840, p. 406), and, doubtless, will increase in 
importance as science advances. 
To these physical characteristics of gases it would be well if we could add the 
temperature of liquefaction, the latent heat of liquefaction, or the measure of the 
solid polar cohesion of molecules according to the vis viva theory, the differential of 
expansion through a range of temperature, and the latent heat of vapours or measure 
of liquid molecular cohesion. 
December 24, 1845. J. J. Waterston. 
This paper being the last in connection with the vis viva theory of gases that the 
writer is likely to have an opportunity of submitting to the Society, he begs, in 
taking leave of the subject, to express a hope that, although the nature of the 
fundamental hypothesis is likely to be repulsive to mathematicians, they will not 
reject it without a fair trial. The principle of the conservation of vis viva involves 
the indestructibility of force, and is a necessary consequence of the quality of perfect 
elasticity or reaction in the ultimate elements of matter : if this last is a universal 
property the first must also be of universal effect, and, as it does not admit of any 
diminution of force in nature, we may question whether, in such intense chemical 
action as the phenomena of combustion and explosion manifest, the sudden evolution 
of force is not merely an exhibition of its transference from one form of elastic matter 
to another. 
Are not the properties of aeriform fluids and of the medium of light glaring proofs 
of the widely spread existence of this quality of perfect elasticity, whatever may be 
