*3 59 



through 20 degrees.34 In explanation of this production 

 of heat, the analogy of the muscle at once suggests 

 itself. No conversion of energy is complete ; and as 

 the heat of muscular action represents force which has 

 escaped conversion into motion, so the heat evolved 

 during the reception of an idea, is energy which has es- 

 caped conversion into thought, from precisely the same 

 cause. Moreover, these experiments have shown that 

 ideas which affect the emotions, produce most heat in 

 their reception " a few minutes' recitation to one's self 

 of emotional poetry, producing more effect than several 

 hours of deep thought." Hence it is evident that the 

 mechanism for the production of deep thought, accom- 

 plishes this conversion of energy far more perfectly 

 than that which produces simply emotion. But we may 

 take a step further in this same direction. A muscle, 

 precisely as the law of correlation requires, develops 

 less heat when doing work than when it contracts with- 

 out doing it. Suppose, now, that beside the simple re- 

 ception of an idea by the brain, the thought is expressed 

 outwardly by some muscular sign. The conversion now 

 takes two directions, and in addition to the production 

 of thought, a portion of the energy appears as nerve and 

 muscle-power ; less, therefore, should appear as heat, 

 according to our,law of correlation. Dr. Lombard's ex- 

 periments have shown that the amount of heat devel- 

 oped by the recitation to one's self of emotional poetry, 

 was in every case less when that recitation was oral ; 

 /. e., 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 converting it into muscular. 



