Active Ingredients. - The active properties of colocynth depend upon the presence of the glucoside colocynthine, C56H64O23, discovered by Herberger, and further investigated by Walz and by Bastick.

Colocynthine is usually seen in amorphous yellow masses, but by very careful evaporation of the alcoholic solution it is possible to obtain small bundles of yellowish-white crystals. It has an excessively bitter taste, and is very soluble in cold and hot water, and in alcohol, but insoluble in ether. Its character is at once displayed if, besides applying the above tests, the solution is boiled: colocynthine is then immediately changed into sugar, and a resin (colocyntheine, C44H84O12), which is precipitated.

There is no reason to suppose that another substance, colocynthitine, a tasteless crystalline body, which Walz procured from colocynth by treatment with ether, has any share in the action of colocynth.

Physiological Action. - The experiments of Schroff show that colocynthine is a very active irritant: 5 to 7 grains killed rabbits in four hours with repeated purging, and the development of an extensive gastroenteritis.

Oolocyntheine, also (the resin which is artificially precipitated by boiling a solution of colocynthine), is stated by Solokowski to be capable of producing colic and diarrhoea, even when given in small doses.

Therapeutic Action. - It unfortunately happens, that, when speaking of the medicinal effects of colocynth, the action of the pure drug is never referred to, but that of colocynth mixed with one or several other agents. In modern practice it has been found that colocynth is too sharply irritant to be conveniently given, except with the addition of carminative and soothing agents, and often in combination with other aperients. It is never given alone; and neither colocynthine norcolocyn-theine have come into medical use. The ancient Greek physicians were accustomed to employ colocynth as a drastic purgative in dropsy, and in lethargic and maniacal cases. They were also well acquainted with its violent effects when injudiciously administered.

In Habitual Constipation, colocynth operates mildly, certainly, and effectively; but care must be taken that it be given at regular, and not too short, intervals.

In Alvine Obstruction, where the bowels have ceased to act for some days, but there is no reason to suspect the existence of any mechanical impediment, colocynth often proves invaluable, and may be conveniently given in enema, rubbed down with soap and water.

In Torpor of the Abdominal and Pelvic Nerves and Vessels generally, colocynth often acts as a most useful corrective stimulant. One of the best instances of this kind of action is its effect in certain cases of chlorotic amenorrhcea; its rousing influence upon the rectum seems to affect the uterus and ovaries by sympathy.

In Apoplexy, Cerebral Congestion (including Congestive Headache, in Cerebral Paralysis, and other Brain Diseases, colocynth sometimes appears to act favorably upon the principle of revulsion or counter-irritation.

In Dropsy, colocynth may prove useful as a hydragogue, though it is greatly inferior to elaterium, since the latter drug evacuates much more fluid in proportion to the degree of intestinal irritation which it causes.

As a Diuretic, colocynth only acts indirectly; but it sometimes exerts this action very beneficially, over and above its purgative effects, when employed for the treatment of dropsy. It is only after a certain persistence in its use that this effect is likely to be attained, a delay which seems to be due to the cumulative action of colocynthine upon the kidneys when it has circulated for some time in the blood. In its general character as a purgative, colocynth, probably, most nearly resembles aloes, and, after this, gamboge. But it appears to act more uniformly upon the whole intestinal tract than aloes; and over gamboge it has a very decided advantage - namely, that while the latter seems to act almost exclusively by its topical acrid influence, colocynth exerts a double power - that is to say, over both the vermicular action and the mucous secretion of the bowels; it is, therefore, at once a more manageable and a more effective remedy. From aloes, again, it differs in being apparently devoid of the tonic qualities which sometimes prove inconvenient in the use of that drug.

Preparations and Dose. - Extr. Colocynthidis, gr. ss. - ij. (.03 - .12); Extr. Colocynth. Co., gr. ij. - x. (.12 - .65); Pil. Cath. Co., No. 1 - 3. Colocynthine is one of the principal ingredients of Laville's gout remedy.