This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
Fig. 324 and 325. A deposit resembling brick dust in color, or a fine, reddish sand, consists of uric acid. The test for uric acid is the following. Place a few crystals on a white plate; add a drop of strong nitric acid; heat over a lamp or candle until the fluid is all evaporated; then add a few drops of hartshorn or aqua ammonia. A bright violet color appearing after the addition of ammonia indicates uric acid.
Fig. 324. Crystals of Uric Acid.
Fig. 325. Crystals of Uric Acid.
If the sediment is formed before the urine is passed, as is indicated by the presence of a deposit in the vessel immediately after the passage of the urine, the presence of gravel or stone in the bladder may be strongly suspected. A brick-dust deposit in the urine is probably chiefly due to inactivity of the liver, as it is the proper duty of this or gan to convert uric acid into urea, a form in which it is soluble and never appears as a deposit.
A patient who has a brick-dust deposit in his urine should abstain from the use of a flesh diet, eating chiefly fruits and grains. Milk may be used in moderate quantities, and eggs and fish may be allowed occasionally; but the less the quantity of meat eaten, the better.