66 CLIMAX OF JOULE : S RESEARCHES. 



that the chemical action in the cells of the battery, as 

 expressed by the product of the chemical affinity of the 

 elements multiplied by the quantity of equivalents electro- 

 lyzed, is equivalent not only to the electrical action but to 

 the heat developed in the entire circuit. Thence showing 

 by absolute measurement that the heat so produced 

 corresponds with the heat produced by the combustion of 

 the same elements, and further, that it corresponds with the 

 heat equivalent of the electric action used in the electrolytic 

 decomposition of the electrolyte formed by combustion 

 provided the elements are brought back to their initial 

 gaseous state. Then the determination of the electric 

 action necessary to convert liquid oxygen into gaseous 

 oxygen, and the determination of the equivalent heat. 



Finally proving, still by aid of the measure of electric 

 action, that the heat developed by "work" done on the 

 magneto-electro machine, and that the heat equivalent of 

 the electric action spent in doing work in the electro-mag- 

 netic engine, have a constant equivalent in the 'work' of about 

 838 lbs. raised 1 foot for each unit of heat which would 

 raise 1 lb. of water 1 degree Fahrenheit. 



Joule had thus, by means of the measure of electric 

 action, traced a definite quantity of physical effect through- 

 out the whole region of physics, recognising it in all the 

 transformations itwas capable of undergoing,and discovering 

 all its modes, flinching at no experimental difficulties 

 to keep it in view until he had brought it again into full 

 light as work or mechanical energy. 



Each one of these discoveries constitutes in itself a great 

 step in physical science, and would have established the 

 reputation of the discoverer ; but the flood of light thrown 

 by their accumulative effect over the whole region of physics 



