DIABETES MELLITUS. 835 



three to one. During childhood and old age it is rarer than dining 

 the prime of life, the period of greatest frequence being between the 

 ages of thirty and forty in males, and in females between ten and 

 thirty. The disease sometimes appears to depend upon hereditary 

 predisposition. The most commonly recognized exciting causes are : 

 exposure to cold and wet, external violence, concussions of the whole 

 body being a more fertile source of the disease than injuries to the 

 brain and spinal marrow ; also immoderate eating of sugar, new wine, 

 and " fruit-must," unfermented juice of fruit, indulgence in immoderate 

 mental exertion, mental depression, intoxication, etc. 



ANATOMICAL APPEARANCES. No constant lesion is found post- 

 mortem in the bodies of those who have died of diabetes mellitus. 

 The most common appearances are the following: extreme emacia- 

 tion, the integument often presenting remains of bed-sores, boils, car- 

 buncles, and sloughs. There is no remarkable lesion in the brain ; in 

 the lungs there are almost always tuberculous, or caseous deposits, of 

 variable age, and not unfrequently pneumonia, or gangrene. The heart 

 is flabby and atrophied ; the liver usually normal, though sometimes 

 hyperaemic. Hypertrophy of the pancreas occurs with remarkable fre- 

 quence, considering how seldom this organ is the seat of disease. The 

 walls of the stomach are moderately thickened, through muscular hy- 

 pertrophy, probably the result of distention. The kidneys are en- 

 larged by hyperaemia, and sometimes are in a state of chronic paren- 

 chymatous inflammation (Brightfs disease). 



SYMPTOMS AND COURSE. The most conspicuous and remarkable 

 symptom of diabetes mellitus consists in the evacuation of enormous 

 quantities of pale urine, whose high specific gravity, contrasted with 

 its limpid aspect and sweetish taste, often alone suffices to place the 

 diagnosis beyond a doubt. It is by no means rare for a diabetic pa- 

 tient, in the course of twenty-four hours, to pass from five to ten thou- 

 sand cubic centimetres of urine (from five to ten quarts), and, in some 

 instances, the daily discharge has been much larger. No credence 

 should be given to the stories of diabetic patients passing six or eight 

 times this amount, or even more. It is maintained by some that the 

 quantity of urine discharged exceeds the amount of liquid which has 

 been drunk during the meals. If this were true, and unless there were 

 a corresponding waste of the body, we should be compelled to assume 

 that, instead of exhaling liquid through the skin and lungs, the patient 

 actually imbibed moisture in this way from the surrounding atmos- 

 phere. Since, as long as the temperature of the body remains higher 

 than that of the air about it, such an occurrence would be incompatible 

 with physical laws, I think it most likely that the observations have 

 been erroneous in the instances where individuals have been reported, 



