This is a disease in which the patient makes an enormous quantity of urine, and in which the urine contains usually an enormous quantity of sugar.

This disease was first described in 1684 by Br. Willis.

Diabetic urine is commonly ligh-coloured and transparent, of a pale straw or greenish tint. Its odour is peculiar. According to Dr. Prout the scent somewhat resembles that of sweet hay, or that of milk; while Dr. Watson compares it to the smell of an apple-chamber. Its taste is, more or less, decidedly sweet, and it is remarkably heavy.

"The quantity of urine secreted and voided, says Dr. Watson, is sometimes enormous; far more than could be supplied by the quantity of fluid taken as drink, although that is excessive too. A healthy person passes from one to three or four pints of urine in the twenty-four hours.. The quantity is liable to considerable variation: perhaps the average may be safely laid at fifty ounces. But patients with Diabetes will void 50 pints in the same time. I have myself known 26; 13 and 14 are not uncommon; and cases are recorded by writers of credit and veracity, in which 70 pints were passed daily. Nay, one Italian author declares that 200 pints have been discharged in that time.

"The saccharine matter thus held in solution may be obtained in a solid form by evaporating the urine. I have seen large flat cakes of beautifully crystallized diabetic sugar. It differs somewhat from common sugar, the produce of the sugar cane; and approaches more nearly to the sugar of grapes. This kind of sugar, which may also be produced artificially from starch, chemists have named glucose. By rapid evaporation of the water, a thick syrup is procured, resembling treacle; but Dr. Maclntyre, who has presented to our hospital museum. some very perfect specimens of this sugar, prepared by Mr. Blandford, informs me that to get it well crystallized, the evaporation in a steam bath should be stopped while the urine is still of thin consistence. It may quickly be reduced to one-half, perhaps, of its original quantity. Then it should be set aside, in shallow plates; and in the course of ten days or a fortnight the sugar will be deposited in an irregularly crystallized mass.

"The sugar is sometimes so abundant, that it undergoes a rude crystallization as the urine dries, wherever it happens to fall. A girl who was in St. Bartholomew's Hospital while I was a student there, observed that if her water were accidentally sprinkled upon her black stuff shoes, every drop left a white powdery spot behind it. So also an aged patient under Dr. Maclntyre's care expressed to him her alarm at finding that her black worsted stockings were sticky and covered with a white dust, from the same cause. A man recently under my charge in the hospital, complained that two pairs of his black trousers had been spoiled in a similar manner. I remember hearing from a diabetic patient in the Edinburgh Infirmary, that his attention was first drawn to his urine by the number of flies and wasps which its sweetness attracted to the chamber-pot. In India the red ants have been observed to swarm in a similar way about a vessel containing diabetic urine.

"So much fluid being evacuated from the body through this channel, it might be expected that the other channels for the excretion of liquid matters would be comparatively dry, and so they are. The skin is dry, harsh, and unperspirable. The patients tell you that they never sweat; that they cannot get into a perspiration. This is a very general symptom: yet in some few patients, especially as the disease draws to a fatal termination, the surface readily becomes humid. And a friend and patient of mine, whose urine was very copious, and contained a notable amount of sugar for several years together, without any perceptible abatement, however, of his general good health, perspired profusely every night. Again, the bowels are mostly costive, an 1 the faeces remarkably solid and free from moisture. The tongue is dry, parched and sticky; sometimes unnaturally red and clean: and the waste of watery particles from the system seems to be felt and expressed by the inordinate thirst which the patients suffer. I remember one girl's telling me that when she was debarred from an excess of water to drink, she would get up if she heard it raining in the night, and catch some of the descending drops to satisfy the tormenting sensation of thirst. And another patient, a very sensible fellow, informed me, that believing it could not be good for him to drink so much, and feeling no confidence in his own resolution to refrain, he was in the habit of betaking himself in the summer time to the fields and dry pastures, where no water was at hand to quench his strong desire for it. The appetite for food is often, but not always, equally keen: and the patients, and especially those in the lower ranks of society, are apt to think, while wondering at their loss of strength, that there cannot be much the matter with them, since they continue to eat and drink so famously.

"Dr. Garrod, after analyzing the urine in several cases of Diabetes, found the daily quantity of sugar excreted to vary from half a pound to.a pound and three quarters. It is most abundant three or four hours after a full meal.

"We need not be surprised then, at the hunger, the wasting, the hectic fever, the feeling of emptiness and sinking at the stomach, the debility, the chilly state of the body and especially of the extremities, the aching and sense of weariness in the loins, and legs, the aversion to exercise, the loss of virility; all of which symptoms are generally present. I may add, to complete the picture, some others, enumerated by Dr. Watt, and confirmed by Dr. Prout, and consistent with my own experience of the disease. They are uneasiness in the stomach after meals, flatulence and acid eructations, dimness of vision, redness of the whole interior of the mouth, sponginess of the gums, looseness of the teeth, and some degree of irritation and inflammatory redness about the external orifice of the urethra; these last are symptoms noticed in persons dying of inanition. Again, listlessness and depression of spirits, weakness and peevishness of temper: the once vigorous mind becomes feeble, oblivious and vacillating: the once amiable temper, fretful, suspicious, and intolerant.