PRODUCTION OF HEAT IN MUSCLE. 



841 



Similar results have been obtained by Eubner l in limbs through which an 

 artificial circulation of blood was maintained. 



Although, as Hermann 2 has shown, some of the carbon dioxide may arise 

 from the action of bacteria, yet these experiments show that even excised 

 muscle is the seat of an energetic metabolism and of heat production. Tissot 3 has 

 proved that the absorption of oxygen and the discharge of carbon dioxide occur 

 in an excised muscle, even when every precaution is taken to maintain asepsis. 

 The results of Minot's 4 experiments upon the production of carbon dioxide in 

 resting and active muscle are opposed to those obtained by Paul Bert and 

 Regnard, but his method has been shown by Zuiitz 5 to be open to serious 

 objections. 



The subject of respiration in muscle will be discussed more fully in other 

 parts of this work, 6 here it is only necessary to point out that the respiratory 

 exchange of a muscle, even during apparent rest, is very marked, and becomes 

 enormously increased during activity. This is well shown by the experiments 

 of Sczelkow, 7 von Frey, 8 Chauveau and Kaufmann, 9 Hill and Nabarro. 10 



The muscles during apparent rest are in a state of tone, and are the seat of 

 an energetic combustion, and therefore of heat production. 



Further evidence of the important part played by the muscles in the 

 production of heat is found in the fact that any cause which suspends 

 the activity of the muscles, or more correctly the rieuro-muscular 

 system, lowers the temperature of the body. Curari causes muscular 

 paralysis and a fall in the temperature of the body ; 11 the respiratory 

 exchange is greatly diminished, even if the animal's temperature is 



1 Arch. f. Physiol., Leipzig, 1885, S. 38; this Text-book, article "Chemistry of 

 Respiration." 



2 " Untersuch. u. d. Stoffwechscl der Muskeln," Berlin, 1867, S. 37. 



3 Arch, de physiol. norm, et path., Paris, 1894, tome xxvi. p. 838 ; 1895, tome xxvii. 



4 " Die Bildung der CO., innerhalb des ruheuden und erregten Muskeln." 



5 Hermann's " Handbuch," Bd. iv. Tli. 2, S. 96. 



6 See articles on " Chemistry of Respiration" and on "Metabolism," this Text-book, 

 vol. i. 



7 Sitsungsb. d. k. ATcad. d. Wissensch., Wien, 1862, Bd. xlv. 



8 Arch.f. Physiol. , Leipzig, 1885, S. 533. 



9 Compt. rend. Acad. d. sc., Paris, 1886, tome ciii. pp. 974, 1057, 1153. 



10 Joum. Physiol., Cambridge and London, 1895, vol. xviii. p. 218. 



11 Tscheschichin, Arch. /. Anat. Physiol. u. wissensch. Med., 1866, S. 159. During 

 the convulsions which are at first caused by curari the temperature rises ; Bernard, 

 "Le9ons sur la chaleur animale," 1876, p. 157 ; Velten, Arch. f. d. yes. Physiol., Bonn, 

 1880, Bd. xxi. S. 361. 



