Definition.—The persistent presence in the urine of an excess of the phosphates.
Etiology.—"A considerable quantity of phosphoric acid is excreted from the blood through the kidneys in health, usually divided between four bases, soda, ammonia, lime, and magnesia, all of which are either soluble themselves, or rendered so by the presence of some acid, the presence of a very minute portion being sufficient for this purpose.
"It may also be deposited in a healthy condition of the system, as after eating, laborious exercise, and especially after severe mental labor; but the deposit continues for only a short time; where continuously deposited, it is always indicative of important functional, and sometimes organic, disease. Dr. Bird remarks that one general law appears to govern the pathological development of these deposits; viz., that they always exist simultaneously with a depressed state of nervous energy, often general, more rarely local in its seat. Of the former, the result of wear and tear of body and mind in old people; and of the latter, the effects of local injury to the spine, will serve as examples. Three forms of phosphatic deposit may be named:
the triple phosphate, phosphate of lime, or calcareous deposit, and the mixed deposit, a combination of the two preceding. The first is always associated with dyspepsia, the digestive functions being poorly performed, the patient irritable and restless. with loss of flesh and strength, so that he is fatigued by slight exertion. The urine is usually copious, of a light amber color; or in some cases it is dark, and of a high specific gravity, 1,025 or 1,030. The deposit of phosphate of lime occurs from urine secreted in large quantity, of low specific gravity, and readily decomposed by the atmosphere. The mixed deposit usually occurs combined with a large quantity of mucus, the urine being pale, fetid, and depositing a thick, mortar-like sediment on standing. It usually occurs in cases of injury or severe diseases of the spine, organic disease of the kidneys and bladder, in the severe forms of dyspepsia, and in persons who have been exhausted by severe mental labor, anxiety, night-watching, and during the progress of cachectic affection that debilitates the system. The symptoms are those of imperfect digestion, mal-assimilation and malnutrition, and disordered innervation.
"Deposits of the phosphates are always white, unless colored with blood, are insoluble in ammonia or liquor potassae, but soluble in dilute hydrochloric acid. In a majority of cases, urine depositing much of the phosphates is alkaline, though they are deposited when it gives an acid reaction with litmus paper; but in this case the acidity does not depend upon free acid, but upon neutral salts. These deposits often settle to the bottom, like a thick cloud of mucus, for which it is frequently mistaken; we may at once detect their true nature, however, by the addition of hydrochloric acid, which dissolves the phosphates, but does not affect the mucus. When examined by the microscope, the triple phosphates present beautiful crystals, of the form of triangular prisms, small stellate concretions, and penniform crystals. The phosphate of lime does not occur in crystals, but occasionally in irregular, crystallized masses. Calculi of phosphate of lime are not of frequent occurrence, but it sometimes forms alternate layers with other matter. When it occurs it is usually small, of a pale-brown color, of a loosely laminated structure, not fusible with the blowpipe, but readily soluble in hydrochloric acid without effervescence. The ammoniaco-magnesian calculus is of a white color and friable, looking a good deal like a mass of chalk; it exhales an ammoniacal odor before the blowpipe, is not affected by caustic potash, but is easily dissolved in dilute acids. Another form of phosphatic calculi has been denominated fusible; it is white, extremely brittle, easily separated into layers, and leaves a white dust on the fingers. It is not affected by caustic potash, is soluble in hydrochloric acid, and is melted into a transparent pearly glass under the blowpipe. Both of these last forms often attain an immense size, and frequently form incrustations on foreign bodies."
Treatment.—"The general treatment will be somewhat similar to the other forms. The bitter tonics and iron, to improve the digestion and the quality of the blood, should be steadily employed. In some cases there seems to be such a loss of tone on the part of the stomach that tonics have no effect: in such cases I direct an emetic two or three times a week, with the happiest results. As in the case of oxaluria I have obtained most excellent results from the use of nux vomica and strychnia, and the collinsonia and agrimonia, quinine, to the extent of from two to eight grains a day, is often of marked benefit.
"The urine should be kept acid to prevent a deposit, and for this purpose dilute nitric acid is most frequently used. The bowels should be kept in a soluble condition, as heretofore named, and strict attention given to the skin, and its secretions favored by the use of the bath, friction, and wearing flannel and warm clothing". The diet should be carefully selected, plain but generous, and, to the considerable extent, of animal food." (Scudder.)