Diabetes Mellitus. 457 



quantity of glycogen in the liver has something to do with the 

 glycosuria; the precise character of the nervous influence is, how- 

 ever, unknown. 



Where the excretion is a persistent and, too, a progressive 

 symptom, provided no unusual quantities of sugar are ingested 

 with the food, there may be said to exist a special disturbance of 

 metabolism, diabetes mellitus (mel, honey; SiajSalvw, , to pass 

 through). In this affection even the ingestion of starch causes 

 the appearance of grape sugar in the urine, so markedly, in fact. 

 that the greatest portion of the starch instead of being assim- 

 ilated passes ofif as sugar; and the urine only remains free from 

 sugar if carbohvdrates are entirely excluded from the food (Krehl 

 and others). While in the milder cases of this disease the amount 

 of proteid ingested has no influence upon the glycosuria, although 

 the sugar is formed normally from proteid also, and while in 

 these cases an increased supply of albuminous diet seems to be 

 quite advantageous to the nutrition of the body, there are cases 

 of a severe type in which even a strict meat diet and even absti- 

 nence from all food do not permit the urine to become free from 

 susrar. Of what nature the metabolic disturbances mav be which 

 ar^ responsible for the imjierfect manner in whicli the carbo- 

 hydrates and the glycogen formed from proteid are dealt with is 

 still rather obscure and confused fcf. Krehl). In a measure the 

 liver normally prevents the direct passage of carbohydrates into 

 the circulation and has the power of removing sugar from tlie 

 portal blood and of storing glycogen. Diseases of the liver affect- 

 ing this function permit a hyperglycremia to develop ; (according 

 to Bimes it ought to be possible to recognize the existence of 

 hepatic disease bv feeding molasses, as in case the liver Avere 

 normal the urine would remain free from sugar while otherwise 

 glucose would become demonstrable in it). Especial informa- 

 tion has been obtained from the excellent investigations of Mering 

 and Minkowski in relation to the pancreas, which have shown 

 that diabetes mellitus occurs when this gland is lost (extirpation 

 degeneration") and that either the pancreatic juice or the glandu- 

 lar parenchyma, the blood from which passes to the liver by the 

 portal vein, has in common with the liver a regulative influence 

 upon the amotmt of sugar in the blood or some power of fixation 

 of excesses of sugar (v. p. 448). [The generally favored view 

 at present among the profession would refer the pancreatic fault 

 to some disease of the islands of Langerhans .(Opie). It is be- 



