734 DIABETES. [BOOK 11. 



several distinct varieties of diabetes may exist. In severe cases 

 of diabetes the aberrant nature of the metabolism which is going 

 on in some or other of the tissues of the body is shewn by the 

 appearance of abnormal substances in the urine. Thus acetone 

 is frequently present, and the fatal issue of certain cases has been 

 attributed to poisoning by that substance ; oxybutyric acid and 

 other various organic, chiefly volatile, acids are also sometimes 

 present. But in respect to these and other abnormal bodies we 

 are not at present clear whether they are like the sugar itself the 

 products of an abnormal metabolism which is the root of the 

 disease, or whether they are secondary products, that is to say, 

 products of the general disordered metabolism induced by the 

 constant presence in the blood of an excess of sugar. We have 

 already in discussing the formation of glycogen called attention to 

 the fact that in severe cases of diabetes the sugar must have a 

 non -amylaceous source ; and the fact that the urea is increased 

 (and that too in some cases in ratio with the sugar) in diabetes, 

 suggests that the sugar may arise from proteids which have been 

 split up into a nitrogenous (urea) and a non-nitrogenous moiety, 

 and so points out the way in which proteids may be a source of 

 glycogen. 



As a sort of converse to diabetes we may mention that the 

 administration of arsenic in sufficient doses or for an adequate time 

 prevents an accumulation of glycogen in the liver and apparently 

 in the body generally, whatever be the diet used. The presence 

 of the metal in the hepatic cell seems to prevent the cell-substance 

 from manufacturing glycogen either from carbohydrate material 

 brought to it, or out of its own substance. As another kind of 

 converse we may also state that the administration of glycerine, 

 especially through the alimentary canal, diminishes the effect of 

 the diabetic puncture, or of morphia or other poisoning, in hurry- 

 ing on the hepatic store of glycogen into sugar, and thus 

 diminishes the sugar in the urine ; the presence of the glycerine 

 in the hepatic cell appears to be in some way a hindrance to the 

 conversion of the glycogen into sugar. Now glycerine injected 

 into the alimentary canal of a normal animal leads to an increase 

 of glycogen in the liver; and the view very naturally suggests 

 itself that this increase arising from the glycerine is to be 

 explained by the glycerine inhibiting in some way a normal 

 conversion of the glycogen store into sugar which is continually 

 going on, and thus increasing for the time that store. 



