808 PHYSIOLOGY 



of the pancreas be removed, the remaining part may gradually become 

 inadequate to prevent diabetes, and Homans has shown that when under 

 these circumstances diabetes supervenes, the granules disappear from the 

 B cells. Changes have also been found in the islets of Langerhans in fatal 

 cases of diabetes in man. It seems therefore probable that what we may 

 term, for lack of a better word, the antidiabetic functions of the pancreas, 

 are associated with and dependent on the integrity of the islets of Langerhans. 

 (5) DIABETES IN MAN. In its severer forms the diabetes of man 

 resembles very closely that produced in the dog by total extirpation of 

 the pancreas. The output of urine is largely increased and the frequency 

 of micturition is often the first symptom noticed. On examination the 

 urine, though light in colour, is of a high specific gravity, 1030 to 1035, 

 and may contain from 5 to 10 per cent, of sugar. The appetite is largely 

 increased, but in spite of the large amount of food taken the body wastes. 

 The excessive quantity of fluid lost by the body gives rise to a constant 

 thirst. The patient may die after some months or years in a condition 

 of diabetic coma. Warning of the onset of this condition is given by the 

 rise of ammonia in the urine and by the appearance of oxybutyric and 

 diacetic acids. The breath may smell of acetone, and this substance may 

 also be present in the urine. On the other hand, the diabetic state is 

 attended by diminished resistance of the tissues to infection. A pimple 

 may become a carbuncle ; a slight sore on the foot may give rise to a 

 rapidly spreading gangrene of the lower extremity ; tubercular infection 

 of the lungs spreads rapidly to the whole organ so as to stimulate pneu- 

 monia. The patient may thus die of some such intercurrent infection 

 before the onset of coma. In a few cases the pancreas is found to be 

 atrophied or diseased, but in the large majority no marked pathological 

 change is to be observed in this organ. Yet the condition is essentially 

 similar to that which occurs in pancreatic diabetes. The radical defect 

 is the inability, relative or complete, of the organism to assimilate carbo- 

 hydrate. We may find all grades between such cases and those in which 

 there is still a considerable power of assimilation. In order to determine 

 the grade of the disorder it is usual to give a test diet with a certain pro- 

 portion of carbohydrate, e.g. 100 grm. of bread with meat, bacon, eggs, 

 butter, green vegetables, cheese, lettuce, coffee and wine. If the urine 

 remains free from sugar on this diet, the diabetes is mild in character. 

 More bread may then be added to the diet from time to time until sugar 

 appears in the urine and the limit of tolerance for carbohydrate has been 

 reached. In many cases the sugar will disappear from the urine on the 

 administration of a diet consisting entirely of proteins and fats. When 

 this has been effected carbohydrates may be added in small proportions 

 to the diet until the limit is found at which the assimilatory powers of the 

 patient are reached. It seems that administration of any carbohydrate 

 in excess of this limit is of disadvantage to the patient and hastens the 

 progress of his disorder. When the power of assimilating carbohydrates 

 is entirely abolished the prognosis is almost absolutely fatal. This point 



