438 ACTUAL WORKING IN ORIGINAL RESEARCH. 



releases the pent-up power in a match ; taps and cocks, 

 pendulums of clocks, also, are releasing conditions of 

 mechanical power ; a certain temperature is a releasing 

 condition of latent heat in the freezing of water, but the 

 lowering of temperature of the water, and the sudden 

 evolution of latent heat, are two essentially different 

 things ; similarly, raising the temperature of ' explosive 

 antimony' to its discharging point, and the sudden evolu- 

 tion of heat, are each distinct phenomena. Even at ordi- 

 nary temperatures some substances unite chemically, and 

 evolve heat when brought into mutual contact ; phos- 

 phorus and iodine, for example ; also arsenic and chlorine ; 

 and in each of these cases a certain range of temperature 

 acts as a releasing and exciting condition. Now it cannot 

 be that free heat is required in either case, because heat is 

 evolved by the action, and what the temperature does is 

 quite a different thing from supplying heat. The human 

 will is probably a realising condition. Whether a force 

 shall be liberated and become active or not, depends both 

 upon the presence of some releasing condition and upon 

 the absence of all those which are preventive. Some 

 releasing conditions are self-acting, such as ball-cocks, 

 overflow dams and syphons, and other contrivances. 



Transmuting conditions are highly important, espe- 

 cially those which cause one form of energy to be changed 

 into another. It would be a great advance made in science 

 to discover the geometric and mechanical conditions of the 

 molecules which determine the change of refrangibility 

 of light and of heat, of the change of heat into electricity, 

 of electricity into chemical power, &c. &c. In each of 

 such cases there must exist a condition (or conditions) 

 which determines the change, and that condition must be 

 of a fundamental character. In the absence of transmuting 

 conditions and of preventive ones, similar causes must 



