Strangury. Constant micturition, only a few drops of urine passing at the time, occasioning burning and cutting pains around the parts. Strangury is generally due to some irritating cause, which should, if possible, be discovered and removed. Cantharides taken either internally, or applied externally, as in the form of a blister, will sometimes give rise to it. The patient should drink copiously of mucilaginous beverages, such as linseed tea, slippery elm bark, barley water, with gum Arabic dissolved in it. An injection consisting of thirty or forty drops of laudanum in a spoonful of gruel will be found to afford immediate relief. If the above means fail, a pill containing a grain of camphor in five grains of extract of henbane should be given, and a warm bath taken. See Gravel.

U′RINE. The density of the urine varies from 1·005 to 1·030;[247] the average, in health, being 1·020, when it contains about 380 gr. of solid matter in the pint. According to Berzelius, the proportion is about 63⁄4%, the rest being pure water. It exhibits a decidedly acid reaction, and is never alkaline, except during disease, or the use of large quantities of alkaline salts of the vegetable acids. The average quantity secreted during 24 hours may be taken at 2 pints to 3 pints; as might be supposed, a larger quantity is passed during the summer than in the winter months.

[247] From 1·015 to 1·025, Beale.

Miller gives the following as the composition of healthy urine:

—

Specific gravity 1·020 In 100
parts of
solid
matter.
Water956·80
Solid matters, 43·2.Organic matters, 29·79Urea14·2333·00
Uric acid0·370·86
Alcoholic extract12·5329·03
Watery extract2·505·80
Vesical mucus0·160·37
Fixed salts, 13·35Sodic chloride7·2216·73
Phosphoric anhydride2·124·91
Sulphuric anhydride1·703·94
Lime0·210·49
Magnesia0·210·28
Potash1·934·47
Soda0·090·12
Loss0·03
——————
1000·00100·00

The presence of bile in urine, or other like fluids, may be detected as follows:—Put a small quantity of the suspected liquid into a test-tube, and add to it, drop by drop, strong sulphuric acid, until it becomes warm, taking care not to raise the temperature above 122° Fahr.; then add from 2 to 5 drops of syrup (made with 5 parts of sugar to 4 of water), and shake the mixture. If the liquid contain bile, a violet coloration is observed. Acetic acid may be substituted for sugar.

Another test for bile consists in pouring a little of the suspected urine into a test tube, and adding to it a few drops of tincture of iodine, when if bile be present the fluid becomes distinctly green. Rosenbach says that urine containing bile, when passed through white filtering paper, imparts a yellow or brown colour to the paper. On allowing one drop of strong nitric acid to run down the side of the moist filter it leaves a yellow streak, soon changing to orange, with a violet border, on the outside of which blue and emerald-green zones may be observed. These colours remain visible for some time.

Dark-coloured urine, owing to substances other than bile, does not produce this play of colours.

The reagents most generally employed for detecting the presence of sugar in urine are Trommer’s (see Sugar) and Fehling’s solutions. For the effective application of Fehling’s test, Dr Roberts[248] advises the following method of procedure:—Pour some of the Fehling’s solution into a narrow test tube to the depth of 3⁄4 of an inch; heat until it begins to boil; then add 2 or 3 drops of the suspected urine. If the sugar be abundant, a thick yellow opacity or deposit of yellow suboxide are produced (and this changes to a brick-red at once if the blue colour of the test remains dominant). If no such reaction ensue, go on adding the urine until a bulk nearly equal to the test employed has been poured in; heat again to ebullition, and no change occurring, set aside without further boiling. If no milkiness is produced as the mixture cools, the urine may confidently be pronounced free from