Diuretics are employed for the following purposes, namely, (1) to remove the excess of fluid in dropsies,—(2) to hasten the elimination of waste products and other poisonous substances from the blood,—(3) to dilute the urine. In

Cardiac Dropsy, or other dropsies due to venous congestion, the best diuretics are those which act on the general vascular system, as Digitalis, Squill, etc. efficient here.

Calomel is very

Dropsy from Renal Disease,—Broom, Nitrous Ether, Oil of Juniper, Digitalis and Squill are the most reliable diuretics in the order named.

Hepatic Dropsy,-Copaiba is considered especially suitable. In this and the previous form a little Pil. Hydrargyri occasionally often aids the diuretic action of other agents. To Eliminate Solids,-Potassium Nitrate and Bitartrate, Turpentine, Juniper, Caffeine, etc., are the most efficient. [Compare ANTILITHICS.]

To Dilute the Urine, -Water is the best diuretic, and the most efficient form is Distilled Water acidified with Carbonic Acid Gas.

Renal Depressants,-are such agents as directly diminish the activity of the renal cells, and lessen or suspend the secretion of urine. Morphine, Quinine and Ergot act in this way through the circulation, and Digitalis, instead of acting as a diuretic, may arrest the renal circulation by stimulating the vaso-motor centre and thus by contracting the vessels may stop the secretion altogether (Brunton). The same is true of Caffeine and Strychnine, hence it is well to combine these with other diuretics (Nitrous Ether, Alcohol), which dilate the renal arteries.

Alkalinizers of the Urine,-are agents which produce an alkaline reaction to the urine when taken internally. They include the alkalies, particularly Potassium and Lithium salts, but excepting Ammonia, which is broken up in the organism. Sodium salts, being partly excreted by the bile and the bronchial mucus, and partly locked up in the system as the neutral chloride, while the Urate of Sodium is insoluble, are not as efficient in this regard as are other alkalies. Fruits, milk and fish also act in the same manner by means of the salts which they convey into the economy.

AGENTS ACTING UPON EXCRETION.

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Acidifiers of the Urine,-are Benzoic and Salicylic Acids, and Vegetable Acids in excess, also excess of proteids, sugar and starch in the food, and certain wines and spirits. The Mineral Acids have little or no influence on the acidity of the Urine, being excreted as neutral sulphates, chlorides, phosphates, etc.

Vesical Sedatives,-are substances which lessen irritability of the bladder, relieving pain and decreasing the desire to micturate. Opium, Belladonna, Hyoscyamus, Stigmata Maidis, Cannabis, etc., lessen the irritability of the nerves, Carbonate of lime that due to the presence of calculi, and mucilaginous drinks, such as Barley-water or Linseed tea, also astringents like Buchu, Uva Ursi, Pareira, etc., diminish the irritation due to chronic cystitis, and antiseptics, as Copaiba, and Cubebs, also act in like manner.

Vesical Tonics,-increase the contractile power of the muscular fibres in the wall of the bladder. Cantharides, Potassium Bromide, Strychnine and Belladonna are the most prominent members of this class.

Urinary Sedatives and Astringents,-act sedatively upon the whole extent of the urinary tract through the medium of the urine charged with them when administered internally. Some of the members of this class may be administered locally, but only to the urethral and vesical mucous membranes, which are accessible to direct local medication.

Instances of the application of these agents are in the use of Potassium and Lithium Salts to diminish the acidity of the secretion,-Cubebs, Copaiba and Sandal-wood Oil as antiseptics and astringents,-and urethral injections of Alum, Acetates of Zinc and Lead, Boracic Acid, Chloral and Zinc Chlorides, etc., for a simple purpose. Copaiba is one of the most efficient agents for rendering the urine antiseptic, and should be more employed in cystitis and urethritis than it is. Oil of Eucalyptus is nearly as efficient, and Stigmata Maidis (Corn Silk), in tincture, is beginning to be well thought of for a general alterative influence on the urinary tract.

Antilithics or Lithontriptics (anti, against, leethos a stone, treebo, I wear down),—are agents supposed to prevent the formation of concretions in the excretory passages (antilithics) or to dissolve them when formed (lithontriptics.) The terms are generally restricted to remedies affecting the urinary calculi, but those directed against the biliary form are included in this arrangement for the sake of consistent classification. chief agents coming under this title are

Biliary Calculi.

Ether and Turpentine.

(Durande's Solvent.)

Sodium Bicarbonate.

Sodium Salicylate.

Sodium Phosphate.

Castile Soap.

Alkaline Waters, especially Vichy.

Uric Acid or Urates.

Distilled Water.

Alkalies, Potash or Lithia.

Potassium Salts.

Lithium Salts.

Potassium Tartraborate.

Magnesium Citroborate.

The

Oxalate of Calcium.

Dilute Nitro-Hydrochloric Acid.
Carbonated Water.

Lactic Acid (for digestion).

Phosphatic Calculi.
Ammonium Benzoate.

Benzoic Acid.
Dilute Nitric Acid.

There is probably little or no solvent value to the agents recommended for biliary calculi. In the case of Uric Acid the administration of Potash or Lithia is based on their combining with the acid forming the calculus, and forming Urate of Potassium or Lithium, which salts are more soluble than the Uric Acid itself.

Diluents (Diluo, I dilute),-are agents which, after their absorption dilute the excretory fluids and enable the latter to hold more solid material in suspension. Water is the one true diluent, whatever form it may be disguised in, as teas, weak fluid foods, acid drinks, etc.

Diaphoretics and Sudorifics (deeaphorheeo, I carry through; sudor, sweat, facio, I make),-are remedies which increase the action of the skin and promote the secretion of sweat. When they act energetically, so that the perspiration stands in beads upon the surface they are known as Sudorifics. They may be subdivided into the following groups, viz.— 1. Simple Diaphoretics, which enter the circulation and are eliminated by the sudoriferous glands, which they stimulate to increased action.

2. Nauseating Diaphoretics, which produce relaxation and the dilatation of the superficial capillaries.

3. Refrigerant Diaphoretics, which reduce the circulation, at the same time acting directly on the sweat centres in the spinal cord and medulla.

The principal diaphoretics are enumerated as follows, the figures referring to their respective supposed modes of action as indicated above, viz. :

Anhidrotics (an, without, heedroce, sweat),—are agents which check perspiration. They may act

1. By depressing the action of the sweat-glands.

2. By depressing the excitability of the sweat-centres.

3. By reducing the circulation in the skin.

The most important agents of this class are the following-named, the figures indicating their mode of action as above arranged, viz. :

AGENTS ACTING ON THE GENERATIVE APPARATUS.

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Strychnine, Atropine, Dover's Powder, Jaborandi, Picrotoxin and Zinc Salts are all respiratory stimulants, and very efficient against the sweating of phthisis, though most of them are classed as diaphoretics. This is explained on the theory of accumulation of Carbonic Acid in the blood by depressed respiration caused by severe coughing, this stimulating the sweat centres, and being opposed by agents which stimulate the respiratory

centre.

AGENTS ACTING ON THE GENERATIVE APPARATUS.

Aphrodisiacs (Aphrohdeetay, Venus),—are medicines which stimulate the sexual appetite and power. They act by reflex or central action upon either the cerebral or the spinal genital centre. Tonics are indirectly aphrodisiac, as are all measures which promote the general bodily nutrition. The chief agents used as direct aphrodisiacs may be enumerated as follows, viz. :

Strychnine acts by increasing general nutrition and exalting the reflex excitability of the genital centres. Hemp probably only causes a mild delirium which may or may not take a sexual direction. Cantharides acts by direct irritation of the mucous lining of the urethra, and is dangerous in aphrodisiac doses. Alcohol in small doses excites the genital centre in the brain; so, also Opium and Camphor, the latter being decidedly anaphrodisiac after a time. The power of Damiana is doubtful. Urtication and Flagellation of the nates produce priapism by irritation of the genital centre in the cord through the sensory nerves of the part. Ergot is considered useful by contracting the dorsal vein of the penis, preventing its emptying too rapidly.

Anaphrodisiacs (an, without, Aphrohdeetay, Venus),—are medicines and measures which lower the sexual function and diminish the sexual appetite. They act by lessening the excitability of the nerves of the genital organs, by depressing the genital centres in the brain and cord, or by decreasing the local circulation. The principal anaphrodisiacs are enumerated as follows, viz.:-—

Emmenagogues (emmayneeah, the menses, ago, I move),-are remedies which restore the menstrual function, either directly by stimulation of the uterine muscular fibre, or indirectly by improving the blood and toning up the nervous system. The direct emmenagogues are ecbolic in large doses. The principal members of this class are enumerated in the following list, viz. :

Oxytocics or Ecbolics (ockseus, quick, tokos, childbirth; ekbolay, abortion),—are agents which stimulate the muscular fibres of the gravid uterus to contraction, and may produce abortion. In small doses the same remedies are emmenagogue as a rule. Their mode of action has not been clearly made known, but it is generally believed to be due in some cases to direct stimulation of the uterine centre in the cord, in others to congestion of the uterus producing reflex stimulation. The principal oxytocics are those enumerated in the following list, viz. :

Ergot.
Ustilago.

Savine.

Quinine.
Borax.
Cotton-root Bark.

Oil of Rue.
Pilocarpine.
Viscum Flavescens.

Any drastic purgative, or gastro-intestinal irritant, may produce abortion by reflex action. The Volatile Oils act in this manner, also Colocynth and many other agents used by women to produce abortion, as Tansy, Pennyroyal, etc., all of which are dangerous to life in doses sufficient to excite the action of the gravid uterus.

Uterine Depressants lower the activity of the nervo-muscular apparatus which controls the uterine contractions.

The most important of

Uterine Tonics and Alteratives,—are medicines which are considered to have such specific influence over the uterus. Authorities differ very much regarding the value of these agents, but those enumerated in the following list are generally considered to have considerable value in uterine therapeutics, viz. :

Those in the first list, except Astringents, are used internally; those in the second column as topical applications to the uterine cavity or cervix.