EXPERIMENTS OK BECQUEREL AND BRESCHET. 879 



also relates a case of tetanus, on the authority of 

 Dr. Prevost, in which the temperature of the 

 body rose 12-6 during the spasms. (Infl. of Phy- 

 sical Agents, p. 490.) 



We further learn from some experiments of 

 Becquerel and Breschet, that the temperature of 

 the biceps muscle of the arm was elevated from 

 1*80 to 2*60, by making it contract repeatedly 

 for five minutes. These results were obtained by 

 uniting two needles at their points, and thrusting 

 them into the muscle when extended, while the 

 other extremities of the needles were connected 

 with the wires of a thermo-multiplier ; when the 

 rise of temperature was measured by the deflec- 

 tion of its magnetic needle. (Cyclop, of Anat. 

 and Physiology, vol. ii.) 



Thus we perceive, that after caloric has per- 

 formed its vital office of causing a muscle to con- 

 tract, it is given out in a free state, when it de- 

 flects the magnetic needle.* 



I have also proved in the fourth Book and 

 fourth Chapter of this work, that so soon as the 

 caloric by which the particles of arterial blood 



* Dr. Edwards observes, that " the first source of the heat 

 evolved during exercise, lies in the voluntary muscles." (Cyclop, 

 of Anat. and Physiology, vol. ii. p. 615.) But we have seen that 

 the " first source" of animal heat is the lungs, where it is obtained 

 from the atmosphere, imparted to the blood, and then to the 

 different organs, where it is expended in maintaining their ac- 

 tivity. And it might as well be said that caloric is generated de 

 novo by hammering a metal, instead of being forced out from be- 



