OF ARTS AND SCIENCES. 



121 



Our results show that in regard to molecular heating, so to speak, by 

 magnetizing and demagnetizing, cobalt stands very close to iron, while 

 nickel is far removed from it. 



Eecapitulation. 



1. It appears from the preceding experiment that the rapid magneti- 

 zation and demagnetization of iron, steel, cobalt, nickel, is accom- 

 panied' by a marked rise in temperature. 



2. Under the same conditions, this rise in temperature is greatest for 

 iron and least for nickel. 



3. The rise in temperature of cobalt in some cases may be as much as 

 that of an equal volume of iron. 



4. The rise in temperature of the magnetic metals submitted to this 

 process is accompanied by a marked increase of work done by the 

 electrical circuit, which can be readily measured by an electrodyna- 

 mometer. 



5. The magnetic metals submitted to the above process severally 

 emit loud musical notes, which rank in the following order : iron, 

 cobalt, and nickel. 



