430 THE CANADIAN NATURALIST. [Dec. 



muscle-force, comes from the food ; and demonstrates that the 

 force evolved by the brain, like that produced by the muscle, 

 comes not from the disintegration of its own tissue, but is the 

 converted energy of burning carbon. ^^ Can we longer doubt, 

 then, that the brain, too, is a machine for the converssion of 

 energy ? Can we longer refuse to believe that even thought is, 

 in some mysterious way, correlated to the other natural forces ? 

 and this, even in face of the fact that it has never yet been 

 measured ?^® 



I cannot close without saying a word concerning the part which 

 our own country has had in the development of these great 

 truths. Beginning with heat, we find that the material theory 

 of caloric is indebted for its overthrow more to the distinguished 

 Count Eumford than to any other one man. While superintend- 

 ing the boring of cannon at the Munich Arsenal, towards the 

 3lose of the last century, he was struck by the large amount of 

 heat developed, and instituted a careful series of experiments to 

 ascertain its origin. These experiments led him to the conclusion 

 that " anything which any insulated body or system of bodies can 

 continue to furnish without limitation, cannot possibly be a 

 material substance." But this man, to whom must be ascribed 

 the discovery of the first great law of the correlation of energy, 

 was an American. Born in Woburn, Mass, in 1753, he, under 

 the name of Benjamin Thompson, taught school afterward at 

 Concord, N. H., then called Bumford. Uojustly suspected of 

 toryism during our Bevolutionary w^ar, he went abroad and 

 distinguished himself in the service of several of the governments 

 of Europe. He did not forget his native land, though she had 

 treated him so unfairly ; when the honor of nobility was 

 tendered him, he chose as his title the name of the Yankee village 

 where he had taught school, and was thenceforward known as 

 Count Rumford. And at his death, by founding a professorship 

 in Harvard College, and donating a prize-fund to the American 

 Academy of Arts and Sciences at Boston, he showed his interest 

 in her prosperity and advancement.''' Nor has the field of vital 

 forces been without earnest workers belonging to our own country. 

 Professors John W. Draper^^ and Joseph Henry^^ were among 

 its earliest explorers. And in 1851, Dr. J. H. Watters, now of 

 St. Louis, published a theory of the origin of vital force, almost 

 identical with that for which Dr. Carpenter, of London, has of 

 late received so much credit. Indeed, there is some reason to 



