DEPOSIT OF EARTHY PHOSPHATES The earthy phosphates, consisting of mag nesia in combination with ammonia and phos phoric acid, are seen as deposits in the urine in two forms, viz. as a monobasic and a bi basic salt. The monobasic phosphate, which is seen in neutral or only slightly alkaline urine, presents the microscopic appearances as under (fig. 793).
The bibasic salt, which is observed in highly ammoniacal urine, gives the following figures (fig. 79 9.
casionally has a light greenish hue. The de posit when allowed to collect in a glass vessel is rarely seen otherwise than as a floating cloud collecting at bottom, and closely re sembling the appearance which would be put on by the presence of an excess of the mucus of the bladder natural to the urine.
It has recently been stated, by Dr. Frick, of Baltimore, that the crystalline masses, in the form of dumb-bells, described by Dr. Bird as
consisting of oxalate of lime, are really com posed of lithic acid. It is true that lithic acid occasionally assumes a form more or less re sembling the dumb-bells figured by Dr. Bird, but scarcely so nearly as to be easily mis taken for them. Dr. Marris Wilson has also recently shown that lithic acid may be made to assume a form nearly approaching in character to the dumb-bells. I have ex amined, with Dr. Bird, some specimens of the dumb-bells, and am satisfied that those we operated upon were composed of lime in com bination with an organic acid. In a paper recently published by Dr. Bird in the Medical Gazette, some reasons are given by him for believing that acid to be the oxaluric, and not the oxalic, and there would appear good grounds for the adoption of that opinion.