URINE. Microscopic examination of the urine is made for the purpose of determining disease or as rough spherical crystals. (c) Hippuric acid crystals are rather infrequently found in acid urine. (d) Phosphates, ammonium-mag nesium or 'triple phosphate' crystals occur in slightly acid and in alkaline urine. They are large and are usually described as 'coffin-lid' in shape. In alkaline urine the phosphates some times come down as fine feathery 'snow-flake' crystals. Calcium phosphate occurs as clear, slender, needle-shaped crystals. Large colorless plate-like crystals of basic magnesium phosphate and granular deposits of the basic phosphates of lime and magnesium may also be found in alka line urine. (e) Calcium oxalate crystals occur in acid urine. They are clear and diamond or 'envelope' shaped. Less common are crystals of a somewhat dumb-bell shape. (f) Calcium car
bonate is found in alkaline urine which is under going fermentation. It occurs as coarse granules which dissolve with gas formation on the addi tion of acetic acid. (g) Less common crystals found in urinary sediments are those of biliru bin, hcematoidia. lencin, tyrosin, and cyst in.
of the kidney, ureter, bladder, urethra, etc. For microscopic examination the specimen of urine should be allowed to stand for from eight to twelve hours and the part examined taken by MCA11S of a pipette from the bottom of the fluid, or the urinary solids may be thrown down by means of a centrifugal machine called the centri fuge. A small drop of the urine is placed upon a glass slide and covered by a thin piece of glass known as 11 cover glass. The specimen may then be examined.