PREVIOUS INVESTIGATIONS. 35 



reduction, while Zuntz^ and Caspari^ both specifically state that owing 

 to the restlessness of the subject they are certain that the basal value 

 has not been found. It thus follows that if the basal value on this 

 man had been found, depressed metabolism would surely have been 

 indicated. 



If it were not for the specially clear evidence obtained from the recent 

 experiments of Loewy and Zuntz, little of positive assurance could be 

 derived from the literature. These experiments, taken in connection 

 with the evidence presented by many of the earlier workers, indicate 

 that with undernutrition there is a loss in weight and a tendency to a 

 reduced metabolism. With a loss in body-weight, one would expect to 

 find a lowering of the total metabolism, but with Loewy and Zuntz, 

 and, to a certain extent, with Jansen's subjects, the metabolism per 

 kilogram of body-weight was likewise distinctly lower during the 

 reduced diet, thus showing that the basal metabolism was specifically 

 lowered. This, they believe, was due to the loss of organic tissue. 

 We thus have here a clear indication of a lower plane of nutrition. 

 Such a change in nutritional level is also indicated by Rubner in 

 his statement in enunciating his law of surface area that animals 

 compared should be in the same state of nutrition. 



On the basis of this evidence, one would expect to find, when exam- 

 ining the basal metabolism of normal men and women, that individuals 

 of very low weight would have a low metabolism, both per kilogram of 

 body-weight and per square meter of body-surface. In fact, data 

 show clearly that thin people have a higher metabolism per kilogram 

 of body-weight and as high a metabolism per square meter of body- 

 surface as have fat people of the same age,^ for while Means^ con- 

 tends that the heat per square meter of body-surface is the same 

 with fat people as with the Du Bois normals, the obese usually give 

 very low values per kilogram of body-weight. Furthermore, athletes 

 (from whom presumably a large amount of body fat has been removed 

 by training) show a higher metabolism than normal, although this is 

 in large part due to the stimulus of cellular activity incidental to exces- 

 sive muscular exercise. Considering individuals in general, therefore, 

 the composition of the body appears to be of appreciable significance, 

 and one may not state that 1 kg. of fat has the same heat-producing 

 power as 1 kg. of active protoplasmic tissue. Consequently one would 

 reason that when fat is lost, there would be a specific increase in the 

 heat production per kilogram of body-weight. Quite the contrary 

 was observed by Loewy and Zuntz. 



On the other hand, aside from fat people, diabetics subsequent to the 

 fasting treatment, and a man fasting 31 days, we have found no class of 



1 Zuntz, Biochem. Zeitschr., 1913, 55, p. 342. 



2 Caspari, Arch. f. d. ges. Physiol., 1905, 109, p. 564. 

 'Benedict, Journ. Biol. Chem., 1915, 20, p. 282. 



* Means, Journ. Med. Research, 1915, 32, p. 121. 



