246 Tr A XS ACTIONS OF THE AMERICAN INSTITUTE. 



tional poetry, "u-as in every case less when that recitation was oral ; 

 i. (?., had a muscular expression. These results are in accordance 

 with the well known fact that emotion often finds relief in physical 

 demonstrations ; thus diminishing the emotional energy by convert- 

 ing it into muscular, l^or do these facts rest upon physical evidence 

 alone. Chemistry teaches that thought force, like 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 disinte- 

 gration 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 conversion 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 ? f 



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 Rum- 

 ford than to any other one man. While superintending the boring 

 of cannon at the Munich arsenal toward the close of the last cen- 

 tury, he was struck by the large amount of heat developed, and 



* Wood, L. n., On the influence of Mental activity on the Excretion of Phosphoric acid by the 

 Kidneys. Proceedings Connecticut Medical Society for 1869, p. 197. 



+ On this question of vital force, see Liebig, Animal Chemistry. "The increase of mass in a 

 plant is determined by the occurrence of a decomposition which takes place in certain parts of the 

 plant under the influence of light and heat." 



" The modern science of physiology has left the track of Aristotle. To the eternal advantage of 

 science, and to the benefit of mankind it no longer invents a horror Tocui, a quinla essentia, in order 

 to furnish credulous hearers with solutions and explanations of phenomena, whose true connection 

 with others, whose ultimate cause is still unknown." 



" All the parts of the animal body are produced from a peculiar fluid circulating in its organisifc, by 

 virtue of an influence residing in every cell, in every organ or part of an organ." 



"Physiology has suflicicutly decisive grounds for the opinion that every motion, every manifestation 

 offeree, is the result of a transformation of the structure or of its substance; that every conception, 

 every mental afi'ection, is followed by changes in the chemical nature of the secreted fluids; that 

 every thought, every sensation is accompanied by a change in the composition of the substance of 

 .the brain." 



"All vital activity arises from the mutual action of the oxygen of the atmosphere and the elements 

 of the food." 



"As, in the closed galvanic circuit, in consequence of certain changes which an inorganic body, a 

 metal, undergoes when placed in contact with an acid, a certain something becomes cognizable by 

 our senses, which we call a current of electricity ; so in the animal body, in consequence of transfor- 

 mations and changes undergone by matter previously constituting a part of the organism, certain 

 phenomena of motion and activity are perceived, and these we call life, or vitality." 



" In the animal body we recognize as the ultimate cause of all force only one cause, the chemical 

 action which the elomonts of the food and the oxygen of the air mutually exercise on each other. The 

 only known ultimate cause of vital force, either in animals or in plants, is a chemical process." 



" If we consider the force which determines the vital phenomena as a property of certain substances, 

 thi§ view leads of itself to a new and more rigorous cousideralion of certain singular phenomena. 



