Now it is obvious that, if by some morbid change in the liver cells they have lost the power of arresting the sugar and converting it into glycogen, the sugar will pass into the general circulation, and that it will appear in the urine. This is what takes place in diabetes. The indication is therefore to check the ingestion of starch and sugar. There is also another dietetic indication given by understanding the normal physiological process. If, as is believed, fat is manufactured from glycogen, the emaciation and weakness so characteristic of diabetes are due to the want of fat in the tissues, which fat is not only deposited in a smaller degree than usual, but is consumed in the production of force. It is therefore obviously necessary that as we deprive the diabetic of the carbo-hydrates of starch and sugar in his food, we should supply their place with the hydro-carbon of fat.

Diabetes may be divided into (1) glycosuric dyspepsia, (2) diabetes minor, (3) diabetes major.

1. In simple cases of glycosuric dyspepsia the disorder seems to be functional. It generally rapidly yields to dietetic treatment, and the sugar which may be present in the urine in the first instance in considerable quantities disappears almost completely, if not entirely, by the rigid exclusion of starch and sugar from the diet. In these cases it seems as if the liver had lost its power of converting sugar into glycogen, and that therefore the sugar ingested with the food, escapes unchanged into the blood. The excessive thirst, the malaise, and the dyspepsia characteristic of the malady disappear on the enforcement of a rigid diet, but they make their appearance again on any relaxation of the regimen.

2. In diabetes minor there is probably some permanent impairment of the powers of the liver; and though by the maintenance of a diet devoid of starch and sugar the amount of sugar in the urine may be considerably reduced, it is scarcely ever banished altogether. It is these cases which derive so much benefit from the treatment by alkaline waters, carried out at Carlsbad and Vichy. This form of diabetes is frequently associated with gout, or what is called the uric acid diathesis. The continual maintenance of an exclusive diet has a quite remarkable influence in cases of diabetes minor; and whereas patients heretofore, before the cause and nature of diabetes were discovered, would drag out a miserable existence, tormented with thirst, growing weaker from increased muscular feebleness and doomed to an early death, they can now be kept in fairly good health by a rational dietary, which it is neither painful nor disagreeable to maintain.

3. Diabetes major generally occurs in young and thin persons, and is a very grave malady. It is little influenced by diet; for though starch and sugar may be excluded, and the patient may be kept exclusively on flesh diet, the liver in this case exercises its power to break up the nitrogenous elements and to extract glycogen from albuminous foods, and even from the tissues of the patient himself; so that he is, as it were, devoured by the abnormal activity of his own liver.