BASAL METABOLISM. 51 



is increased for any reason, either by previous alcoholic excess 1 or by 

 preceding diet, 2 the increment in the heat production per unit of work is 

 not measurably altered. This is in full conformity with the contention 

 of Johansson and Koraen 3 to the effect that the thermal processes 

 accompanying food ingestion and those accompanying muscular work 

 are entirely distinct from each other. The only striking illustrations 

 in the literature of the opposite of this hypothesis are the observations 

 of Durig, 4 whose technique it is very difficult to criticize adversely; 

 his results should therefore be considered as absolutely established 

 facts. In Durig's Vienna experiments the basal metabolism was 

 approximately 1 calorie per minute, while in the Monte Rosa experi- 

 ments it was 1.26 calories per minute. The increment due to the 

 ingestion of sugar was 0.268 and 0.306 calorie per minute in Vienna; 

 on Monte Rosa with the same amount of sugar it was 0.206 and 0.115 

 calorie per minute. It would seem, therefore, as if with the higher base- 

 line the sugar had a less stimulating effect. 



For all practical purposes, however, we need not at present consider 

 these special conditions, but may assume that if the base-line is deter- 

 mined under conditions of complete muscular repose, the increment 

 measured will represent the true effect of the ingestion of food upon the 

 metabolism irrespective of whether the subject is asleep or awake. 

 The possible variations in the magnitude of this effect, due to the sub- 

 ject being either asleep or awake, call for experimental evidence, and 

 as yet we have none at hand. 



BASAL VALUES USED IN THIS RESEARCH. 



As the researches recorded in this publication have extended over a 

 considerable period of time, namely, from 1904 to 1915, and this period 

 has witnessed a rapid development of technique in all forms of metab- 

 olism measurements, it is not surprising that we find variations in the 

 interpretation of the significance and importance of the base-line and 

 in the method of studying the metabolism following food ingestion. 



The experiments reported in this publication may be divided into 

 three groups: First, those 24 hours in length; second, those approxi- 

 mately 8 hours in length; and third, those in which the individual 

 periods were of short duration. The variations in the length of the 

 period naturally resulted in a variation in the method of obtaining the 

 basal metabolism. In the 24-hour experiments the basal metabolism 

 was determined for each individual for one or more days and compared 

 with 24-hour values determined on other days for the metabolism after 

 food ingestion. In the earlier 8-hour experiments, the basal metab- 



*Benedict and Murschhauser, Carnegie Inst. Wash. Pub. No. 231, 1915, p. 78. 



2 /btd., pp. 80 and 93. 



'Johansson and Koraen, Skand. Arch. f. Physiol., 1902, 13, p. 251. 



*Durifi;, Denkschr. d. Wiener Akad. d. Wiss., 1909. 86, p. 116. 



