INGESTION OF CARBOHYDRATES. 201 



in effect, even though its intensity may not be so great as that noted in 

 some of our experiments, the use of the base-line for the longer period 

 would be more justifiable and more truly indicative of the actual con- 

 ditions than a base-line for a short period. Accordingly, while the 

 values given in table 123 for the greatest increment above the basal 

 metabolism may not be taken as indicating a prolonged effect at this 

 level of intensity and should only be interpreted as the possible maxi- 

 mum level to which the basal value may be raised, the percentage 

 values in table 124 must be interpreted by taking into consideration 

 simultaneously not only the total amount of increment measured but 

 the basal value and particularly the length of the experimental period. 

 As uniformity in results may not be expected with experiments of 

 different length, these percentage values can have but little relative 

 mathematical significance other than to explain the low values noted 

 by investigators during 24-hour periods when carbohydrates are given. 



Although the experiments with pure carbohydrates are better 

 adapted for comparison purposes than those with mixed carbohydrates, 

 the discussion of the total increments in the metabolism as a result 

 of the ingestion of the former will be deferred until the results of the 

 respiration experiments are considered, as by far the larger number 

 of experiments with the pure carbohydrates were made with the 

 respiration apparatus. Still it is of significance to note from table 124 

 that with sucrose the total increment above the basal value for the 

 entire period of measurement was 10 per cent in one case, and with 

 the maltose-dextrose mixture it was 14 per cent in two cases. 



The percentages for the total increment above the basal value as 

 computed for the mixed carbohydrates are likewise shown in table 124. 

 The starch as ingested in the experiments with mixed carbohydrates 

 was in three forms: first, in popcorn, which was dry and hence must 

 undergo the process of imbibition in the stomach; second, in rice, which 

 was cooked; and third, in the moist starch of bananas. The popcorn 

 experiments were primarily designed to throw some light upon the 

 ingestion of roughage in the diet and those with rice to give the effect 

 of cooked starch. The effect of uncooked starch was studied with 

 bananas, of which large amounts could be eaten with considerable 

 ease. As carried out, however, the experimental method was some- 

 what faulty in that the bananas were given, in all but three experi- 

 ments, with relatively large amounts of cane sugar; hence we have 

 unquestionably a double influence upon the metabolism. 



Total increments for bananas and sugar are frequently found of 

 17 to 24 per cent, showing very perceptibly the influence of the inges- 

 tion of this mixture of carbohydrates. No great stress should be laid 

 upon these computations, owing to the irregularities in the length of the 

 observations and the fact that frequently the metabolism returned to 

 the basal value before the experiment ended. Nevertheless, the gen- 



