Urates

Urates is the salts of uric acid. There are average urates, easily soluble in water, and acid urates, or biurate that do not dissolve in water. When cooling concentrated urine in the vessel walls falls brick-red precipitate Muratov K, Na, CA, Mg, easily soluble adding alkalis. Uric acid ammonium (biuret ammonium) can fall in alkaline urine as brownish balls covered with needles. When added to the urine acetic acid or hydrochloric acid urates go into uric acid (see) and form a rhombic crystals Golden-yellow color.
Sour urates in the form of crystals are deposited in the joints, causing arthritis, bursitis, and in the form of sand and stones in the bladder and kidneys.
The excretion of uric acid and its salts increases in some diseases associated with the decay of tissue (leukemia that resolve pneumonia and other), as well as severe renal failure.
Cm. also Urine (research), Uraturia.