5^ SUMMARY OF RESULTS. 



curious to ascertain whether the same amount of caloric 

 would be evolved by the mechanical condensation of eight 

 grains of oxygen gas." 



This is only a passing remark, but it is interesting as 

 showing that the significance of the discovery that part of the 

 electromotive force of his battery is occupied in performing 

 an operation which may be reversed by mechanical means, 

 has not escaped his notice, and has excited his curiosity. 

 This comes out again in the observations he makes at the end 

 of his paper. There are six of these observations. In the 

 4th he says : — 



" Faraday has shown that the quantity of current 

 electricity depends upon the number of chemical equiva- 

 lents which suffer electrolysis in each cell, and that the 

 intensity depends on the sum of the chemical affinities. Now 

 both the mechanical and heating powers of a current are, 

 per equivalent of electrolysis in any one of the battery-cells, 

 proportional to its intensity or electromotive force. There- 

 fore, the mechanical and heating powers of a current are 

 proportional to each other." 



In the 5th observation, he says : — 



" The magnetic electrical machine enables us to convert 

 mechanical power into heat by means of the electric currents 

 which are induced by it, and I have but little doubt that by 

 interposing an electro-magnetic engine in the circuit of a 

 battery a diminution of the heat evolved per equivalent of 

 chemical change would be the consequence, and this in 

 proportion to the mechanical power obtained." And in a 

 note (Feb. 18, 1843), "I am preparing experiments to test 

 the accuracy of this proposition." 



Had he stopped here, it would have been almost 

 impossible to avoid the conclusion that he had not only 



