DEATH AND RESURRECTION. 89 



no connection apparent to external ob- 

 servation. 



For a long time it was also believed 

 that no such relation existed. It was 

 only after 1840 that several scientists 

 made the startling discovery almost 

 simultaneously that physical forces may 

 be transformed one into another. It 

 proved possible to transform a certain 

 quantity of heat into an equal quantity 

 of mechanical energy, which again 

 might be turned into equivalent quan- 

 tities of electricity, light, chemical en- 

 ergy, etc. It was further found that 

 these processes might be undertaken in 

 the reverse order, so that the original 

 form of energy could be restored in un- 

 changed quantity and with unmodified 

 qualities. Nothing was lost and noth- 

 ing was added. 



Kecent science is founded entirely on 

 these facts, which later generations 

 probably will consider as the greatest 

 of all the discoveries of the last cen- 

 tury. 



This law of the permanence and the 



