This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Pimento consists of the dried unripe berries of Myrlus Pimenla (Eugenia Pimento, De Cand.), a handsome tree, growing in the West Indies, Mexico, and South America, where it is indigenous, and cultivated in Jamaica, whence the fruit derives the name of Jamaica pepper.
Sensible Properties. The berries are similar to those of black pepper, but rather larger, and smoother. They are of a brown colour, a fragrant odour, and a warm, pungent, aromatic, slightly astringent taste. The odour has been thought to resemble that of a mixture of other spices; and hence the name of allspice,.by which the fruit is generally known.
According to the analysis of Bonastre, the active constituents are volatile oil, a green acrid fixed oil, and a little tannic acid. Berzelius, however, thought that the green acrid fixed oil of Bonastre was a mixture of volatile oil, resin, fixed oil, and perhaps a little chlorophyll. This is probably true; so that, as the tannic acid is of little or no account, the berries may be considered as owing their virtues exclusively to their volatile oil. This, when first obtained by distillation, is colourless; but it changes with time, and ultimately becomes reddish-brown. It has the flavour of the fruit.
Pimento became known as a spice very soon after the discovery of America. Its effects are those of the aroma-tics generally, without any special distinguishing property. It may, therefore, be used for the same purposes as other pure aromatics (see page 315), being preferably prescribed, when its odour and taste are peculiarly agreeable to the patient. It is much more used in cooking than as a medicine.
The dose of the powder is from ten to forty grains; that of the Volatile Oil (Oleum Pimentae, U. S.) from three to six drops. A Water of Pimento (Aqua Pimentae, Br.) is made either by distilling water from the bruised fruit, or by simply dissolving the oil in distilled water, and given in the dose of one or two fluidounces. A Spirit of Pimento, prepared by dissolving the oil in diluted alcohol, was formerly officinal; but it has been omitted in the late revision of our Pharmacopoeia. The dose was one or two fluidrachms, or more.