CHAP, iv.] METABOLIC PROCESSES OF THE BODY. 769 



and on the other hand that the changed blood interferes with the 

 processes by which the sugar, produced in a normal fashion, is got 

 rid of by the economy. Though the former view is perhaps- the 

 more probable one, neither can at present be said to be proved or 

 disproved, nor is there any evidence that either in this artificial or 

 in natural diabetes the sugar accumulating in the blood is of a 

 different nature from the dextrose normally produced by the liver. 



The diabetes thus set up by extirpation of the pancreas has 

 further the following resemblance to ordinary diabetes. In mild 

 forms of the natural disease, sugar only makes its appearance in 

 the urine when carbohydrate food is taken ; but in severer forms a 

 large quantity of sugar may be present in the urine even though 

 no carbohydrate food at all be taken. The sugar in such a case 

 probably comes, as we have already said, from the splitting up of 

 proteid matter, and this view is supported by the fact that a 

 certain relation may be observed between the sugar and the urea 

 secreted in the urine. So also after extirpation of the pancreas, 

 especially if some of the pancreas be left behind, a mild effect may 

 be produced, in which sugar appears in the urine only after carbo- 

 hydrate food. On the other hand severer forms are also met with 

 in which sugar passes away by the urine, though carbohydrates be 

 rigidly excluded from the food. 



In grave cases of natural diabetes, various abnormal substances 

 are produced or certain substances are produced in abnormal 

 quantity and make their appearance in the secretions. Thus 

 acetone is frequently present in the urine, and the fatal issue of 

 some cases has been attributed to poisoning by this substance; 

 oxybutyric acid and other organic chiefly volatile acids have also 

 been found. It is stated that these substances also make their 

 appearance in artificial pancreatic diabetes. Now when sugar is 

 injected in large quantities into the blood of an animal the ureters 

 of which have been tied to prevent the elimination of the sugar by the 

 urine, the disappearance of the sugar from the blood is accompanied 

 by the appearance of acetone in the blood, and of unusual quan- 

 tities of lactic acid in the blood and especially in the tissues. 

 This result points to the acetone and like bodies, found in diabetes, 

 being products of the decomposition of the sugar in excess, the 

 decomposition being carried out by some or other of the tissues ; 

 but further inquiries are needed in this matter. 



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 glycerin, 

 especially through the alimentary canal, diminishes the effect of 



