BASAL METABOLISM. 



119 



apparatus in Stockholm and the Jaquet apparatus in Basel, and subse- 

 quently by means of another apparatus employing a spirometer, 

 Miiller valves, and mouthpiece, in the Poliklinik in Basel. Since the 

 data obtained with the Stockholm apparatus were exclusively confined 

 to carbon-dioxide production, they can not be taken as comparable 

 values for indicating constancy in the total heat production. Never- 

 theless it is important to note that, even on the basis of the figures 

 presented by Gigon, variations of nearly 10 per cent are found, which 

 far exceed in many instances the variations found in observations fol- 

 lowing the ingestion of the several foodstuffs. 



Accordingly, in the final selection of a determined basal value, it is 

 of fundamental importance that we should bear in mind the fact that 

 in averaging a large number of experiments the tendency is for all of the 

 irregularities to be eliminated. For a comparison with an average value 

 obtained from a large number of food experiments it may be justifiable 

 to use a basal value of this kind, but in a comparison with the results 

 of only one or two food experiments the variations in the single periods 

 must be taken into consideration. 



While in this research our experience in securing a general basal value 

 for use is by no means satisfactory, it has occasionally been necessary to 

 use an average base-line. Inasmuch as a large number of values were 

 secured, it is probable that any variations in the individual values will 

 be more or less eliminated in the grand average. Nevertheless it is 

 quite clear that a general base-line, even for a well-trained subject who 

 is experimented upon each day, can not properly be used for studying 

 the minor factors influencing basal metabolism, such as may be found 

 in connection with the ingestion of certain of the food materials studied. 



TABLE 48. Oxygen consumed at different times of day in respiration experiments; subject 



M. A. M., in post-absorptive condition and lying on couch. (Values per minute.) 



Average age, 29 years. Average body-weight (naked), 66.0 kilograms. Height, 177 cm. 



experimental periods were usually 15 minutes in length and there was but one period in 

 each half hour. 



