246 



FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



TABLE 183. Average respiratory quotients at intervals following the ingestion of 100 grams 



pure carbohydrate in respiration experiments. 



mum figure in the case of levulose appearing in 40 to 60 minutes, while 

 the dextrose quotients remain essentially at the same level from the 

 first to the fourth hour after the beginning of the experiment, with an 

 absolute maximum from 2 to 2| hours. With sucrose the maximum 

 effect appeared 20 to 40 minutes after the beginning of the experiment, 

 while with lactose the maximum was found in the same period as with 

 dextrose, i. e., in the 2 to 2| hour period. 



It should be remembered that occasionally the quotients given in this 

 table represent values for a single period. For instance, the quotient 

 0.87 for the sixth to seventh hours with dextrose was obtained in one 

 period (see table 179), while the figure 0.76 given for the fifth to the 

 sixth hours with sucrose is also an individual value. As a rule, however, 

 the quotients given in this table are the average of three or four values 

 and may be considered as reasonably representative of true averages. 



The highest absolute values were recorded in the levulose experi- 

 ments, although the sucrose maximum of 1.03 is but little less than the 

 levulose maximum. It should furthermore be noted that the values 

 for dextrose are lower throughout all of the periods; it is true that the 

 basal value was also lower, but if a correction of 5 points is made in the 

 maximum of 0.92, we should obtain a quotient of only 0.97, which 

 would be measurably lower than the maximum with either levulose 

 or sucrose. Similarly it is clear that the lactose values are measurably 

 lower than those for sucrose or levulose. The average maximum rise 

 with dextrose is 12 points, lactose 14 points, levulose 18 points, and 

 sucrose 21 points. Thus we see that not only do levulose and sucrose 

 exert an effect upon the metabolism which is shown in the quantita- 

 tive relations of the total measurable metabolic factors (see table 178), 

 but they likewise possess specific characteristics which affect the char- 



