AND DIABETES 105 



substance. To give precision to the test it is usually 

 wise to catheterize both ureters, and to analyse the 

 urines separately. 



(d). Pancreatic diabetes. Removal of the pancreas 

 in dogs or other animals if complete induces fatal 

 diabetes exactly corresponding to severe cases of the 

 disease in man ; a sub-total removal induces a milder 

 type of the disease. The symptoms are improved by 

 pancreatic grafting. If less than four-fifths of the 

 pancreas is taken away, ro glycosuria follows. After 

 complete removal, but not after removal of four-fifths, 

 sugar will continue to appear in the urine even when 

 all carbohydrates aie excluded from the food, being 

 derived in this case from the breaking down of food 

 and body protein. 



In ordinary human diabetics, the pancreas is found 

 at autopsy to present some abnormality in such a 

 large proportion of cases that the smaller group in 

 which nothing is found amiss may safely be attributed 

 to functional deficiency apart from organic disease. 

 To quote an analogy, mental defect is so often 

 associated with gross changes in the brain that we 

 think we are justified in assuming that there must be 

 some functional derangement of that organ, even when 

 in cases of insanity it appears to be quite normal. 



In what way may destruction of the pancreas 

 conceivably produce diabetes ? 



The present-day teaching is that the pancreas 

 supplies to the blood some internal secretion, some 

 chemical substance, which is carried to the muscles 

 and other tissues to enable them to make use of the 

 sugar brought them by the blood. The tissues are 



