FATS, CARBOHYDRATES, AND ALBUMINS. 341 



If we apply these relations to the metabolism of a diabetic, we will 

 appreciate the great derangement of his energy economy. In the severe 

 form of this disease, the organism loses not only the greater part of the 

 energy of the carbohydrates, but also the energy required to transform 

 fat or protein into sugar; and as a part of the sugar so formed is eliminated 

 by the system, the loss becomes a double one. The fact that the diabetic, 

 whose blood and tissues are saturated with sugar, and who is already 

 greatly injured as regards the economy of energy by means of the loss he 

 suffers because of his inability to consume sugar, even prepares more 

 sugar from the other nutrients, only to eliminate it eventually as such, 

 shows us that the assumption that diabetes is only a simple derangement 

 of carbohydrate metabolism does not satisfactorily explain the disease. 

 Up to the present time the most prominent symptom, that of glucosuria, 

 has dominated the entire investigation of problems concerning diabetes, 

 and it is very probable that this is the reason why the disease, as a whole, 

 is so little understood. 



We have intentionally gone somewhat into detail concerning these 

 relations, because we are unable to follow any other function so exactly 

 as that of muscular work. All the other organs are only indirectly acces- 

 sible to our observation. We do not know whether they also are able to 

 utilize all three of these materials, fat, carbohydrate, and protein, in like 

 manner* as sources of energy. O. Cohnheim l has recently performed an 

 experiment in this direction. He tried to decide whether the digestive 

 glands obtained their energy requirements mainly or exclusively from pro- 

 tein. As we shall see later on, it is possible to stimulate the digestive 

 glands without introducing into the alimentary tract food which would 

 then participate in the metabolism. Cohnheim made an oesophageal 

 fistula in a dog according to the method of Pawlow, and after a period of 

 fasting fed the animal. The food eaten by the animal fell out through the 

 fistula tube at every swallow, so that no nourishment was actually received 

 by the dog. Not only are the salivary glands stimulated by this " fictitious 

 feeding," but the stomach also. On account of the acid gastric juice 

 passing from the stomach into the duodenum, the pancreatic gland also 

 begins to secrete its fluid. By estimating the amount of nitrogen present 

 in the urine on days of fasting and those on which the fictitious feeding 

 day took place, Cohnheim succeeded in showing that the activities of the 

 digestive organs were without influence upon the transformation of albu- 

 min. No increased elimination of nitrogen took place. This does not by 

 any means prove that the digestive glands do not work with albumin. 

 It is possible that, while the digestive glands are decomposing albumin, 

 an equivalent amount of albumin is being " spared " in some other part 

 of the body. Such an assumption becomes all the more plausible when 



1 O. Cohnheim: Z. physiol. Chem. 46, 9 (1905). 



