for a few
days either in an open or a closed bottle. Soon a white, flaky deposit
will be observed, which will become more and more dense, and finally
fine grains will be seen precipitated at the bottom of the bottle.
Similar grains, lodging in the folds of the bladder, gradually increase
in size, by the precipitation of more salts around them, and ultimately
become a source of much irritation. When of large size, they are termed
_calculi_ or stones. When these formations occur in the kidneys they are
termed _renal calculi_; when in the bladder, _vesical calculi_. There
are several varieties of gravel, each depending upon different
conditions of the system for its formation. The two prominent varieties
are the red, containing uric acid, and the white, or phosphatic, gravel.

SYMPTOMS. When the deposits are in the kidneys, there is pain in the
back and loins, occasionally cutting and severe; sometimes it darts down
the course of the ureter to the bladder, and extends even to the thighs.
When the deposits are in the bladder, there is a frequent desire to
urinate, with a bearing-down, straining pain; also a cutting or
scratching sensation in the urethra during micturition. In the male,
intense pain is often experienced at the end of the penis. When the
urine is voided in a vessel and allowed to settle, a gravelly deposit is
seen, generally of a red or a white color, and the particles varying in
size.

TREATMENT. These urinary deposits indicate a general derangement of the
system, as well as a local disease. Nutrition is imperfect and some of
the excretory organs are not properly performing their functions, or,
perhaps, some portion of the body is being too rapidly wasted. Very
frequently we find these gravelly formations as the result of a
rheumatic or a gouty diathesis. It is also a well-known fact that
torpidity of the liver throws an excessive amount of work on the
kidneys. These organs then, in part, perform the function of the liver,
and hence unnatural activity is required of them, and the secreting of
such substances as uric acid, which precipitates readily and gives rise
to severe irritation of the urinary canal.

In order to treat these cases rationally and successfully, it is first
necessary to ascertain by microscopical and perhaps chemical
examinations, the character of the deposit. By such an examination, the
exact condition of the system which gives rise to these abnormal
products may be definitely determin