PILLS are the most generally convenient and popular of all forms of medicine. are formed from masses of a consistence sufficient to preserve the globular shape, and yet not so hard as to be of too difficult solution in the stomach and intestines. This form is especially suitable for (1) all remedies which operate in small doses, as metallic salts: (2) those which are designed to act slowly and gradually, as certain alteratives; (3) those which are too readily soluble when exhibited in other forms; (4) substances whose ope• ration it is desirable to retard untii they have reaeLed the lower intestines, as in certain pills for habitual costiveness; (5) bodies whose specific gravities are too ineonsideralIe to allow their suspension in aqueous vehicles; and (6) fetid substances: it is unsuitable for (1) medicines which require to be given in large doses; (2) deliquescent salts; (3) fluid or semi Iluid substances, such as oils, balsams, etc., which require a very large proportion of some dry powder to render them sufficiently tenacious to form into a mass; (4) substances so insoluble, that when exhibited in solid form they pass through the intestinal canal unaltered, as extract of, loomed (Paris's Pharmacologia, 9th ed. p. 550). Many substances, such as vegetable extracts, may be at once tanned into pills any addition; but most substances require the additiou of a material termed an excipient, for converting it into a pill-mass. The excipients in most common use are
bread-crumbs,' hard soap, extract of liquorice, mucilage, syrup, treacle, honey, castor oil. and conserve of roses. From the property of preserving pills for a long time in a properly soft state, the most valuable excipient is the conserve of red roses; and, per Imps, next to it treacle is the most valuable excipient, as it does not undergo any change by time, but maintains a proper consistence, and preserves the properties of vegetable powders unimpaired for years. It is common to place pills in some fine powder, to pre vent them from adhering to each other, and to conceal their taste. For this purpose, liquorice powder, wheat flour, starch, and magnesia are generally used in this country, and lyeopodium on the continent. Pills retain their moisture and activity far longer in small bottles than in the ordinary pasteboard boxes. The ordinary weight of a pill is 5 grains; if it much exceeds that weight, it is too bulky to swallow conveniently if it consist of vegetable matter. It is very common to meet with patients who express their inability to take this form of medicine. If, however, they practice with a small globular mass, toward which they feel no repugnance, as a pellet of bread or a currant; placing it on the back of the tougue, and gulping it down with water, they will soon get over the difficulty.