[Illustration]

Mix the liquids thoroughly, without shaking, by reversing the tube a
dozen times, close with a cork, and allow it to stand upright for
twenty-four hours. The height at which the coagulum then stands, read
off on the scale, will indicate the number of parts per thousand, or
grammes of albumen in one liter. This divided by ten gives the
percentage. Dr. Esbach's test solution is prepared by dissolving 10
grammes of picric acid and 20 grammes of citric acid in 900 c.c. of
boiling distilled water, and then adding, when cold, sufficient water
to yield 1 liter. The citric acid is only employed for the purpose of
maintaining the acidity of the liquid, and is really not essential.


URIC OR LITHIC ACID.

The determination of the proportion of uric acid in urine was formerly
rather neglected by physicians. There is now, however, a growing
tendency in a certain class of diseases to attach considerable
importance to its accurate estimation, and, as some little trouble is
involved, pharmacists should be prepared to undertake the work. A
rough way is to concentrate somewhat, acidulate with hydrochloric
acid, and collect and weigh the precipitate thrown down on standing.
There are several objections, however, to this method, and many
attempts have been made to elaborate a more reliable process. One of
the most recent, and which has been pronounced the most practical and
successful, has been devised by Professor Haycraft. Although
apparently rather detailed and elaborate, the determination is easy
and extremely simple.