532 ENERGY EXCHANGE AFTER FOOD 



depends and to what degree the work of digestion is to be 

 held for the related phenomena, possibly experiments with 

 parenterally introduced protein or "mock feeding" would 

 be suitable methods of definitely differentiating the points 

 in question; however, according to the judgment of as 

 experienced an expert in this subject as W. Caspari 36 this 

 does not seem to be the case. A number of authors are dis- 

 posed to the view that introduction of protein acts in a 

 sense as a direct stimulant which excites the cells of the body 

 to increased oxidatipn processes. Possibly the recent ob- 

 servations of E. Grafe, suggesting that over-nutrition in 

 animals and human beings induces a decided exaggeration 

 of the combustion processes, may be interpreted in this 

 sense ; a man, in whom in the course of six weeks an increase 

 of weight of fifty per cent, was attained by excessive hyper- 

 nutrition, manifested a very marked exaggeration of heat 

 production not only after introduction of food but also in 

 periods of fasting (in this last condition an increase of 

 eighty per cent. ) , 37 Zuntz and Hagemann have found that the 

 increased consumption of oxygen in the horse after feeding 

 maize amounts to about twenty-five per cent, more than when 

 the same amount of oats is fed, and they remark that it would 

 be quite a risk to assume in this connection any work-in- 

 crease on the part of the digestive tract capable of raising 

 the metabolic process by as much as one-fourth. They be- 

 lieve the most likely idea is that there is some unknown 

 chemical substance in the corn which stimulates the cells 

 of the animal body to exaggerated oxidations. Jaquet 38 

 comes to the conclusion from this that if such possibility be 



36 Literature in reference to the Specific-dynamic Effect of Protein : A. 

 Jaquet, Ergebn. d. Physiol., 2', 478-486, 1902 ; A. Lowy, Handb. d. Biochem., 4', 

 266-271, 277-284, 1908; R. Tigerstedt, Nagel's Handb. d. Physiol., 1, 351-375, 

 1901; Handb. d. Biochem., 4", 1-42, 1910; W. Caspari, ibid., 4', 775-778, 1911. 



81 E. Grafe and D. Graham (Med. Clinic, Heidelberg), Zeitschr. f. physiol. 

 Chem., 73, 1, 1911 j E. Grafe and R. Koch (Med. Clinic, Heidelberg), Deutsch. 

 Arch. f ; klin. Med., 106, 564, 1912. 



88 A. Jaquet, 1. c., p. 486. 



