DEX′TRO-RACE′MIC ACID. See Racemic acid.
DIABE′TES. See Urine.
Diabetes (Saccharine). The symptoms observed in this generally fatal ailment are the passing of an excessive quantity of pale, straw-coloured urine, of high specific gravity, containing more or less grape sugar; great thirst and hunger, obstinate dyspepsia, constipation, an unpleasant odour from the feet, or perspiration of the arm-pits, and bodily debility, and emaciation. All these symptoms vary in intensity according to the course and duration of the disease, which is frequently accompanied with hectic fever, cough, and sometimes carbuncles, and generally ends in consumption or some organic disease. The flow of urine sometimes reaches as much as eight gallons in 24 hours; the average quantity, however, is about two gallons. The specific gravity of the urine varies between 1030 and 1070. The quantity of sugar excreted in the twenty-four hours differs greatly, ranging from half a pound to three pounds.
In the treatment of diabetes, great attention should be paid to diet, which should consist principally of digestible, broiled, or roasted meat, gluten and bran bread (these latter being substituted for ordinary bread, which with sugar must be especially avoided), liquids in moderate quantity, of which the most preferable are weak beef tea or mutton broth. If the thirst is extreme, it is best assuaged by drinking water acidulated with phosphoric acid. Spirituous liquids as well as saline aperients should be eschewed. Claret is, however, a suitable beverage.
Small doses of laudanum, given three or four times a day, have been found of great service.
Dr Watson recommends also the administration of creosote. The bowels must be regulated by means of mild aperients. Warm baths are also of use, as they augment the secretion of the skin. The disease may be kept under by administering from twenty to forty minims of tincture of perchloride of iron, 3 times a day. The above treatment is inserted for the guidance only of emigrants and others unable to obtain professional aid; wherever this can be obtained, no time should be lost in seeking it. This is the more important, since the earlier the patient has recourse to the proper remedies, the greater are the chances of recovery.
Horses. The disease occurs, although rarely, in horses. It is not known either in cattle or dogs. The treatment consists in depriving the animal for some weeks of food containing starch, or other matters capable of forming sugar. He must be fed on meat soup and cooked animal diet, to which he quickly becomes reconciled. The strength must be kept up by means of tonic. To counteract the intense thirst, Mr Finlay Dun recommends the following to be given three times a day in water:—A drachm of iodide of potassium, a scruple of iodine, and four drachms of carbonate of soda.
DIACH′YLON. See Plasters.
DIALY′′SER. In practical chemistry, an instrument for separating ‘crystalloids’ from ‘colloids,’ introduced by the late Prof. Graham. In its most convenient form it consists of a hoop of gutta percha, over which a circular piece of parchment paper is stretched. The paper is applied to the hoop while wet, and is kept stretched by a second hoop, by an elastic band, or by a few turns of string. The instrument, when complete, resembles an ordinary tambourine. It is distinguished as the ‘HOOP DIALYSER,’ The fluid to be ‘dialysed’ is poured into the hoop upon the surface of the parchment paper, to a small depth only, such as half an inch, and the dialyser is then floated upon water in a large glass basin. Another form of dialyser, termed the ‘BULB DIALYSER,’ consists of a small glass bell-jar, the mouth of which is covered by a piece of parchment paper. This is suspended or otherwise supported in a large vessel of water in such a manner that the parchment paper septum just dips below the surface. See Dialysis (below), Parchment paper.
DIAL′YSIS. In practical chemistry, the method of separating substances by ‘diffusion’ through a septum of gelatinous matter. When a solution having a sp. gr. greater is introduced into a cylindrical glass vessel, and then water very cautiously poured upon it, in such a manner that the two layers of liquid remain unmoved, the substance dissolved in the lower liquid will gradually pass into the supernatant water, though the vessel may have been left undisturbed, and the temperature remain unchanged. The gradual passage of a dissolved substance from its original solution into pure