INTRODUCTION. 5 



nevertheless they remain as possible and plausible criticisms of the conclusion 

 drawn from our earlier work. The later experiments were therefore planned 

 further to clarify the situation and to remove cause for criticism. 



It also became necessary to secure additional data with regard to nor- 

 mal individuals. During the progress of this investigation a large number of 

 normal subjects have been studied in connection with the respiration researches 

 in this laboratory, and hence the data are continually increasing. They will 

 here be presented in abstract to show normal metabolism under conditions of 

 experimentation similar to those used with the diabetics studied. 



Furthermore, a study of the influence of the ingestion of carbohydrates 

 upon the metabolism of diabetics was deemed of great importance. The 

 early investigations of Nehring and Schmoll, 1 Magnus-Levy, 2 and Leo 3 indi- 

 cated that with the ingestion of carbohydrates there was frequently no increase 

 in the respiratory quotient. Similarly there was apparently no great increase 

 in the sugar excreted in the urine; at least the increase was not sufficient to off- 

 set the excess carbohydrate ingested; and while there may have been a posi- 

 tive carbohydrate balance on that particular day, the respiratory exchange did 

 not indicate a combustion of carbohydrates, since it was not materially higher 

 than during fasting. This presented an anomalous situation in that while 

 carbohydrate was ingested in large amounts, it apparently was neither burned 

 nor excreted, and the question therefore immediately arose as to where this 

 carbohydrate had disappeared. For the purpose of throwing light upon the 

 problem a number of experiments were made in this laboratory in which vari- 

 ous carbohydrates were ingested, chiefly levulose and oatmeal, the latter being 

 used particularly on account of the great interest in the so-called "oatmeal 

 cure" for diabetes. Under these conditions the metabolism was studied very 

 exactly in short periods following the ingestion of various amounts of carbo- 

 hydrates in order to determine whether there was an increase in the metabolism 

 or a variation in the respiratory quotient which would indicate a difference in 

 the character of the metabolism as the time progressed. In this way it was 

 hoped that some light would be thrown upon the character of the metabolism 

 and the apparent storage of carbohydrate. 



In at least one or two of the earlier experiments we found an apparently 

 abnormal reaction to the ingestion of protein. With normal individuals the 

 ingestion of protein, particularly in the form of beefsteak, shortly produces a 

 rise in metabolism, i. c, the "specific dynamic action" of the protein. With 

 one of the cases previously reported (Case A) this rise in metabolism did not 

 appear; it was therefore suggested that possibly when the body was extremely 

 glycogen-poor the non-nitrogenous portion of the protein molecule split off 

 when the steak was ingested and was deposited as glycogen instead of being 

 burned, and that the specific dynamic action of the protein might be due to 

 the rapid combustion of the non-nitrogenous parts of the protein molecule. It 



Nehring and Schmoll, Zeitschr. f. klin. Med., 1897, 31, p. 59. 

 2 Magnus-Levy, Zeitschr. f. klin. Med., 1905, 56, p. 86. 

 "Leo, Zeitschr. f. klin. Med., 1891, p. 101. 



