CONCLUSIONS NOT ALTOGETHER JUSTIFIED. 69 



There is, too, another questionable statement in Joule's 

 paper of July, 1843, which shows that he was somewhat 

 dazzled and confused in the general view he took of the 

 results he had obtained — a confusion directly connected 

 with the practical conclusions which he draws. This is in 

 the general statement of the results already quoted. He 

 therein says : " The quantity of heat capable of raising the 

 temperature of a pound of water one degree Fahrenheit's 

 scale is equal to and may be converted into a mechanical 

 force, capable of raising 838 lbs. to a perpendicular 

 height of one foot." It is as to the expression may be 

 converted into, that the important question arises — is this 

 established by his research? Has he, as yet, shown that 

 heat may be converted into power ? He has unquestionably 

 shown that power may be converted into heat, and that 

 electrical action and chemical action, by means of electrical 

 action, can be converted into their equivalents of either power 

 or heat, but in the detail of his papers he has hitherto been 

 careful to speak of the production of power by electrical 

 action, " as attended by a diminution of the free heat that 

 would otherwise have appeared in the circuit " — not in any 

 case implying that he has converted free heat into mechanical 

 power any more than into chemical action, necessary to 

 effect electrolytic separation in the decomposing cell. Thus, 

 if the term heat in his general statement is understood to 

 mean free heat, this statement as to the conversion of 

 heat into work was at the time unproved. That Joule 

 considered the statement true in this sense is shown by the 

 practical conclusions already discussed, but in making the 

 statement he no doubt referred to the latent-Jieat residing 

 in the battery or the uncombined elements, which he had 

 discussed in a previous paper, and in this sense the state- 



