Black pepper consists of the dried unripe berries of Piper nigrum, a climbing plant, indigenous in the East Indies, where it is also largely cultivated, especially on the coast of Malabar, in the peninsula of Malacca, in Siam, and in the islands of Java and Sumatra.

White pepper is the ripe fruit, deprived of its outer coating by maceration in water. It is weaker than the black, and is little used in this country.

Sensible Properties. Black pepper is too well known to require description. Its odour and taste are familiar to every one.

Chief Constituents. These are volatile oil, a soft acrid resin, and a peculiar crystalline principle called piperin. The volatile oil may be separated by distillation with water. It is at first limpid and colourless, but becomes yellow by age. Its odour is strong, and resembles that of pepper; but the taste, though warm and pungent, is less acrid than that of the berries themselves. The acrimony resides chiefly in the soft resin, which is semi-fluid, of a deep-green or blackish colour, extremely acrid, insoluble in water and the volatile oils, but readily dissolved by alcohol and by ether. Piperin is a crystalline substance, white, inodorous, and tasteless when perfectly pure; but, as commonly obtained, yellow and acrid. At least this is the statement made by Pelletier; but Dr. Christison says that the whitest and purest crystals he had been able to procure were as acrid as the coloured, and emitted an intensely irritating vapour when thrown on a heated iron plate. It is insoluble in cold water, slightly soluble in hot water, and readily soluble in alcohol, ether, and acetic acid.

Medical Properties and Uses

Black pepper has been known as a medicine and condiment from the time of Hippocrates. It has the properties of the aromatics in general, but is much more stimulating than most of them, and acts with still greater proportionate energy on the stomach than on the general system. It is thought to have a specially excitant effect on the urino-genital apparatus, and probably stimulates the urinary passages through the direct contact of some one of its ingredients, altered or unaltered, with the mucous membrane of these passages, as it escapes with the urine. In contact with the skin, it is highly irritant, acting as a rubefacient, and sometimes, it is said, blistering. When taken too largely, it may produce serious irritation or inflammation of the stomach, with general febrile phenomena; and its long-continued use in excess endangers a loss of excitability in that organ, with or without chronic gastritis. It is much more employed as a condiment than as a medicine. In the former capacity, it not only serves to impart an agreeable flavour, but often facilitates the digestion of substances ordinarily of difficult solution in the stomach, especially fresh vegetables when boiled. Care should be taken, however, not to abuse it, for fear of the evil consequences just referred to. As a medicine, it is given occasionally in torpidity of the stomach and bowels, with flatulence, especially in old people, in whom these organs are apt to be inert It is thought to act directly upon the mucous coat of the rectum, and thus to prove useful in chronic ulcers of that part, in piles, and fistula in ano. From its influence upon the urinary and genital passages, it has been recommended in gonorrhoea, gleet, and leucorrhoea; but care should be taken not too much to excite these parts, when there is any tendency to acute inflammation.

Much attention has been directed to black pepper from its supposed possession of antiperiodic properties. It was recommended in paroxysmal fevers by Celsus and Dioscorides; but, though occasionally used in domestic practice in intermittents, it seems for along time to have been lost sight of by the profession. Louis Frank, in imitation of a practice which he had witnessed in the East, was induced to try it in this complaint, and found it successful in a hundred and seventy cases, which recovered as rapidly as under cinchona, and with less tendency to relapse. (Trousseau et Pidoux, Trait de Therap., etc., 4e ed., ii. 465 ) Many others followed the example of Frank, and the remedy came into great repute, which it has not yet entirely lost. There is no doubt that it will often cure intermittents; and, in cases of great torpidity of stomach, as in drunkards, it may with advantage be associated with sulphate of quinia, in order to arouse susceptibility to the action of the latter remedy. When used alone, it should be preceded by a thorough evacuation of the bowels; and it is recommended to administer it in the form of whole grains, as less liable than the powder to irritate or inflame the-stomach.

In reference to its local effects, black pepper is sometimes used as a direct application to the mouth or fauces, in paralysis of these parts, relaxed uvula, severe toothache, etc. Externally it may often be usefully employed as a rubefacient, for which purpose it may be made into a cataplasm, with or without other irritants.

It may be given whole, or in powder. The dose is from five to twenty grains. In intermittens it has been recommended preferably, as already stated, in the whole form; and eight or ten grains of it may be given three or four times a day.

There is an officinal Confection (Confectio Piperis, Br.), consisting of black pepper and caraway, incorporated with honey. It has been highly recommended in piles, in which it is employed as an officinal substitute for an empirical remedy, which acquired much credit, in the treatment of this affection, under the name of Ward's paste. Sir B. Brodie has found it successful in severe cases, and recommends that it should be continued for two, three, or four months. The dose is from one to three drachms, twice or three times a day. It should be accompanied with a laxative, in order to prevent inconvenient accumulation in the bowels; and should not be used when the parts are inflamed.

An Oleorexin (Oleoresina Piperis, U. S.; Extractum Piperis Flu-idum, U. S. 1850) is directed by the U. S. Pharmacopoeia, in which the virtues of the medicine are extracted by ether, and this fluid subsequently evaporated. It contains the volatile oil and acrid resin of the pepper; and, as the piperin is of doubtful efficacy, may be considered as representing the virtues of black pepper. It is a thick, opaque, greenish liquid, having the smell of pepper, and an acrid, burning taste. A residuary matter, left in the process of preparing piperin, has been kept in the shops, under the name of oil of pepper. It has a black colour, and is essentially of the same character as the fluid extract, though of less uniform strength, and therefore less to be relied on. The dose is one or two minims, which may be given in emulsion, or in connection with other medicines in the pilular form.

Piperin has had considerable reputation in the treatment of intermittent fever, having been supposed to be the active principle of black pepper. As found in the shops, it certainly has some effect, and has been used successfully in that complaint. Dr. Meli, an Italian physician, who was the first, I believe, to employ it, considered it superior to Peruvian bark. It has been much employed also in this country, particularly in connection with sulphate of quinia. As before stated, however, there is much reason to doubt its efficiency when pure. According to Pelletier, the acrid taste, and consequently the medicinal activity of the impure form in which it is commonly found, are owing to a portion of the acrid resin remaining mixed with it. The dose is stated at from one to ten grains. A drachm has been given in twenty-four hours without inconvenience. Meli considers that two or three scruples are sufficient to cure intermittents.

An ointment, made by rubbing one part of powdered pepper with three or four parts of lard, was formerly employed in scald-head, but is little used at present.