640 SUPPLEMENTARY. 



demonstrated by the principle of the conservation of electricity, 

 is of such a nature as to oppose the production of the original 

 phenomenon. We thus rediscover, in a more general way, Lenz's 

 law (511) relative to the phenomena of induction. 



These few examples will be sufficient to show how the general 

 principles of the science enable us to connect the most varied 

 phenomena, and even to determine their numerical relations, 

 without its being necessary to know the intimate nature of the 

 forces which come into play. 



END OF VOL. 



