512 Proceedings of the Royal Society 
done on the gas, the elaborate researches of Joule and Thomson 
on the “ Thermal Effects of Fluids in Motion,” would lead us to 
believe that hydrogen of all gases would in this new condition retain 
the greatest amount of its original store of energy. But before 
a just comparison can be made with the results of Joule and 
Thomson, careful determinations must be made of the electro-motive 
force, latent heat, &c., of hydrogenium. Professor Tait has deter- 
mined by a new process the electro-motive force of platinum and 
palladium covered with oxygen and hydrogen, and the result will 
be communicated to the Society in a short time. 
2. Some Observations on Free, An-atomic, or Transmissible 
Power. By R. S. Wyld, Esq. 
This is an abstract of the first of two papers on the subject, pre- 
pared for the Society. 
Physical bodies may be held, in accordance with chemical science, 
to consist of aggregations, either of material atoms, or of atomic 
circles, or centres of force. 
There are certain exhibitions of physical power observed in con- 
nection with those atomic bodies, the laws and actions of which are 
in the highest degree worthy of study. Mr Wyld calls power exhi- 
bited in this way, free an-atomic or tranmissible power. 
Mr Wyld called attention to seven exhibitions of this free power, 
viz. — 
1st, The attraction of gravity ; 2d, cohesive power ; 3d, the power 
of chemical affinity; 4th, animal power; 5th, the momentum of 
moving bodies ; 6th, the electric force set free on the mechanical 
disintegration of quartz and many other crystals ; 7th, the force 
obtained alike through the decomposition, the dissolution, and the 
combustion of simple and compound bodies. 
The consideration of the nature and source of animal power 
Mr Wyld reserved to his second paper. 
In the present paper Mr Wyld directed attention to the momentum 
or force of moving bodies, and to the law of its transmission from 
one body to another, as illustrated in the case of one rolling ball 
hitting another and imparting its force to it — and in the case of 
