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.
Cloves are the dried unexpanded flower-buds of Caryophyllus aromaticu8, a small and beautiful tree, inhabiting the Molucca Islands, in the East Indies, whence it has been successfully transplanted to various parts of the world, as the Isle of France, Singapore, Sumatra, and Cayenne in South America, in which places it is now cultivated to a considerable extent Sensible Properties. Cloves have the form of a small nail, being on the average somewhat more than half an inch long, with a round head, having four spreading points beneath it. When pressed with the fingernail, if of good quality, they exude oil. Their colour is dark-brown, their odour strong and fragrant, and their taste hot, pungent, aromatic, and lasting. The powder is dark and oily.
Chief Constituents. The active principle of cloves is a volatile oil, which may be separated by distillation. When first procured, it is colourless, but gradually becomes yellowish by time, and ultimately reddish-brown. It has the odour and taste of the cloves; but is relatively less pungent. It is heavier than water. Besides the oil, there are two crystalline principles, called respectively caryophyllin and eu-genin, and a little tannic acid; but the first two are insipid, and the last is of no practical importance. Cloves yield their active matter only in small proportion to water, but freely and entirely to alcohol. The alcoholic extract is excessively fiery, but becomes insipid when distilled, while the oil which comes over is relatively mild. Distillation would appear, then, to have produced some change in the oil, which renders it less active.
Cloves were made known to Europe by the Arabians, but were not largely used until after the discovery of the passage to India by the Cape of Good Hope. They possess, in a high degree, the characteristic properties of the aromatics, and may be used for all the purposes mentioned in the general observations on this subdivision of the tonics. They are, however, much more employed as a condiment in cookery, than as a medicine. Occasionally they are given to correct nausea, relieve flatulent pains, and stimulate the languid digestion; but their chief medicinal employment is as an adjuvant to other medicines, and they form a subordinate ingredient in several officinal preparations.
The dose of the powder is from five to twenty grains. The officinal Infusion (Infusum Caryophylli, U. S.) is made with two drachms of the cloves to a pint of boiling water, and given in the dose of two fluid-ounces. The French Codex directs a tincture, of which the dose is a fluidrachm. The Oil of Cloves (Oleum Caryophylli, U. S.), prepared by distillation from cloves, is occasionally employed either alone, in the dose of from two to six drops, properly diluted, or as an ingredient in purgative pills, to prevent nausea or griping. It is also used to relieve toothache, by being introduced, upon cotton, into the carious hollow. It relieves the pain by blunting the sensibility of the part through excessive irritation.