become ammoniacal, but becoming concentrated by the absorption of water, remains acid, but forms deposits of various kinds. These cases have evidently no analogy with those of partial retention, and can therefore not tell against the views here adopted. Ammoniacal urine is always fetid, pale, and turbid, from the precipitation of triple phosphate and phosphate of lime. The smell, and the presence of the crystals of ammoniophosphate of magnesia, easily distinguish it from urine which is only turbid by alkalinity from fixed alkali, and contains a precipitate of phosphate of lime, or phosphate of lime and magnesia. Urine which is alkaline from the presence of bicarbonates (after Vichy water) is mostly clear, the earthy phosphates being soluble in the second equivalent of carbonic acid, which easily separates from the carbonate. We have thus advanced to the consideration of that group of alkaline urines which impart to red test-paper a permanent blue colour, showing that they are produced by fixed alkalies. When the alkali is present in quantity sufficient only to neutralize the free acid of the urine, then the latter exerts no influence upon any test-paper; it is neutral. But it must be borne in mind that the reaction of healthy urine being acid, neutrality of the fluid in itself denotes alkalinity. While, on the one hand, the presence of volatile alkalies in the urine is always pathological, the alkalinity from fixed alkalies on the other hand, though it may be, and in many cases is of a morbid nature, occurs more frequently within the range of perfect health. Certain descriptions of vegetable food, such as apples, lemon-juice, and a series of acid fruits, make the urine alkaline in a very short time. Dr. Bence Jones found that 120 grains of the dry tartrate of potash, dissolved in four ounces of water, made the urine alkaline after thirty-five minutes. The alkalinity had disappeared after two hours. A gentleman ate an apple for experiment, and found his urine alkaline in less than an hour. acetates, tartrates, citrates, and malates, in fact the salts of many of the organic acids, are, by the oxydizing influence of the chemistry of the body, converted into the carbonates of their respective bases, and being as such discharged with the urine, give it their characteristic reaction. It is for this reason, and some others, that the urine of herbivora is always alkaline. The In man this description of alkalinity, which may occur for hours or days, or at a certain time after meals, is of no practical importance. It becomes so, however, when it is the consequence of the use, as medicines, of the caustic alkalies, soda and potash,' and of the earths, magnesia and lime, or their carbonates. This artificial disease not unfrequently occurs when patients to whom alkaline remedies have been prescribed by their medical advisers, continue to take them on their own account for an unreasonable length of time. I have already stated that the neutral or alkaline condition is of frequent occurrence with the pale urine discharged in anæmic conditions. Of the reason of the alkaline reaction in these cases we can as yet give no satisfactory account. But it seems probable that the depression of the organism in these cases, accompanied as it is by faulty nutrition of the muscular and nervous systems, does not allow of the accomplishment of that chemical process, by the completion of which, in health, acid combinations are discharged from the tissues and blood. It is in this direction that we may have to search for the truth. Meantime, we may safely adopt the empirical, but highly practical doctrine of Rademacher, which Vogel' himself adopts, admitting its merit; namely, that a constantly alkaline (and let me add, constantly pale) urine requires the employment of tonics, particularly iron. 2 The continuance of the alkalinity of urine from any cause, but particularly from alkaline fermentation and the maladministration of fixed alkalies, for any length of time, is to be considered a serious matter. For the phosphates of magnesia and lime, being precipitated, and mixing with the increased amount of mucus, may at any time, and unawares, form a stone, with all its consequences; or the turbid and caustic condition of the urine may give rise to diseased states of the bladder, which it is afterwards frequently a matter of great difficulty to remove. Table showing the Substances which cause the Reaction of Urine expelled from the Bladder. A. ACID REACTION: imparting a permanently red colour to litmus paper. Common in health: due to a. Free acids. a. Oxalic B. Malic y. Tartaric acids, and their acid salts, when taken in large and repeated doscs. (Buchheim.) 8. Free acid (nature unknown). E. Phenylic acid . Taurylic acid n. Damaluric acid 9 Damolic acid } questionable. 1 See Fatty Tumours: action of Liquor Potassæ.' Letter from Dr. Thudichum, 'British Medical Journal,' Aug. 15, 1857, p. 702. 2 Rechtfertigung der verstandesrechten Erfahrungsheillehre,' 2d ed., vol. ii, p. 211, et seq. 3 Loc. cit., p. 177. c. Neutral salt with acid reaction. a. Chloride of ammonium (questionable). B. NEUTRAL or ALKALINE REACTION: Occurring in health occasionally, more frequently in disease: due to a. Fixed alkali, imparting a permanently blue colour to red litmus paper. B. Carbonates of the earths, lime and magnesia. y. Pus, blood, and serum. b. Volatile alkali-ammonia; carbonate of ammonia, from decomposition of urea, being a result of— a. Uræmia (questionable). B. Retention of urine, caused by weakness, or paralysis of bladder, or by obstruction to discharge of urine, as from enlarged prostate : the ferment being mucus, or a retained portion of the already fermented urine. y. Decomposition of urea, under the influence of a continued discharge of fixed alkalies by the urine. c. Deficiency of phosphoric and sulphuric acids, in alkalinity or neutrality of pale urine, occurring in anæmic conditions. CHANGES ON COOLING. In colour the urine becomes a trifle darker on cooling; its peculiar smell becomes very weak, partly because it does not evaporate any longer with the vapour of water, partly because there is less of it. The epithelia collect in masses and clouds towards the bottom of the vessel, leaving the supernatant fluid perfectly clear and transparent. If the urine have been concentrated and dark, it will frequently deposit a reddish crust against the walls of the vessel containing it. This crust, and the pulverulent deposits of urates, which are formed at different stages of the process of cooling, may occur in persons enjoying apparently perfect health. As a general rule, it may be said that the more coloured a deposit of urates is, the longer time has it required for its formation. A lady having lost her child, was obliged to retain the milk in her breasts. When the painful swelling of the bosom had ceased, she discharged urine, which, on touching the vessel in which it was received, became white like milk, and was brought to me as milk. When only a small quantity was passed, the milk-like condition was at once apparent; the vessel withdrawing a sufficient amount of warmth from the urine to precipitate the urate. But when a larger quantity was passed, the first portion made a precipitate, which was redissolved as the larger portion was added. Ten minutes, however, were sufficient to make the precipitate appear, which consisted of snowy-white urate of ammonia. Dark-coloured urines mostly throw down the urates after standing during some time. In a case of heartdisease with dropsy, the brownish-red urate only fell after twenty-four hours; in a case of colic, only after twelve hours. In these three cases the temperature could not have been the only influence exerted upon the urine, because in each case the urine must have been of the temperature of the air long before the deposit fell, and in the first case the deposit fell before the urine was of the temperature of the (warmed) room. In some few cases the urine may become alkaline during the process of cooling (vide p. 9). If sediments are discharged with or formed in the urine they subside towards the bottom of the vessel. Among the sediments, besides mucus, the urates, uric acid, and the oxalate of lime are most common. Most other deposits are due to the decomposition of urine, and of the urates in some cases. CHAPTER II. QUANTITY OF URINE AND INGREDIENTS. MODES OF COLLECTING THE URINE. To collect urine is not an easy task, and requires great attention. The requirements are to collect the whole of the urine without losing any portion, and to collect it in such a manner as to preserve its purity. It is essential to keep all vessels used for the purpose scrupulously clean, and to wash and scald them at least once a day. If practising among the poor, the physician will find it necessary to order that the chamber-vessel be kept covered when not used, in order to protect the urine from the admixture of dirt and rubbish falling from the patient's bed. In many diseases it is desirable to collect in separate vessels the several portions of urine passed at different times of the day and night. Several small pots will best suit this purpose. In hospitals and other public institutions a very convenient form of glass is in use. The glass consists of a flat body which easily lies on its bottom, a turned-up narrow neck, and a mouth fitted to the requirements of the sex. For men it is therefore funnel-shaped; for women the funnel is made ellipsoidal, so as to receive the vulva. If the urinals described were combined with a pan of a suitable construction, the urine might be collected in a most easy manner. The pan requires only to have such a gap in its front border and wall as will admit the neck of the urinal standing in front of it. In men, the penis will lie easily in the neck of the urinal; and if women take the trouble of sitting a little closely on the oval funnel of the urinal, not a drop of urine can possibly be lost. |