CARBOHYDRATES. 93 



contains glycogen, and sometimes it does not contain a trace of this poly- 

 saccharide. This is not astonishing when we remember that the name 

 diabetes includes quite a number of different diseases, all of which show 

 the common symptom of glucohemia. 



We will now attempt to answer the question as to whether diabetes can 

 be explained entirely on the assumption that it is due to a diseased pancreas. 

 It is certainly interesting to compare diabetes with the glucosuria pro- 

 duced by extirpation of the pancreas. It has been shown in many cases 

 that the pancreas of diabetics was diseased, and there is absolutely no 

 doubt but that there are forms of diabetes which originate in a disturbance 

 of the functions of the pancreatic gland. Recently changes have been 

 noticed, particularly at the islands of Langerhans, and also many degen- 

 erations have been observed, e.g., hyaline degeneration. At the present 

 time it is impossible to decide whether the conclusion may be drawn that 

 there is positively a connection between the cells of the Langerhans group 

 and the metabolism of carbohydrates. At all events, the fact that in many 

 cases of diabetes the post-mortem examination shows these cells to be 

 absolutely normal, does not necessarily show that any such assumption is 

 false, for it is not possible to trace all forms of diabetes back to a common 

 cause; and furthermore, the fact that there is no noticeable histological sign 

 of a change having taken place in the tissues, does not prove that the cells 

 have suffered nothing as regards their functional activity. Perhaps the 

 researches of Diamare and Kuliabko * will eventually settle this question. 



Let us return to the question as to the sugar formed not being consumed. 

 It is possible that diabetics in general have a limited capacity for oxida- 

 tion. On the other hand, the fact that the other forms of nourishment are 

 taken care of normally speaks a priori against any such assumption. The 

 following experiments are a direct proof that the organism of diabetics 

 possesses its full oxidation capacity. O. Schultzen 2 found that diabetics 

 readily consume the alkali salts of lactic and the vegetable acids, also 

 inosit and mannitol. M. Nencki and N. Sieber 3 observed that patients 

 suffering from severe diabetes could take care of the difficult ly-oxidiz able 

 benzene just as well as the healthy organism could. Direct respiration 

 experiments likewise showed that the respiratory exchange in such cases 

 severe cases of diabetes did not vary from the proper physiological 

 relations. It is true that von Pettenkofer and C. Voit 4 found that there 

 was a considerable diminution in the inspired oxygen and expired carbon 

 dioxide, and drew the conclusion that this was due to a decreased capacity 

 for oxidation; but this conclusion was later abandoned by Voit 5 himself, 



1 Loc. dt. 2 Ber klin Wochschr. No. 35 (1875). 



3 J. pr. Chem. N. F. 26, 35 (1882). 4 Z. Biol. 3, 380 (1867). 



5 Physiol. allg. Stoffwechsels und der Ernahrung (1881), p. 227, et seq. 



