All emetic substances, with nauseating properties, may be employed as expectorants. I shall content myself with considering specially ipecacuanha and tartar emetic. Lobelia and sanguinaria are used for the same purposes by some American practitioners; but all that is necessary has been already said of them in the class of emetics. Squill and seneka might, by their nauseating properties, when given in large doses, be ranked in the same category; but their locally stimulant properties are so considerable as to more than counterbalance the nauseating, as they are ordinarily administered; and they will be best considered in the stimulant division.

I. Ipecacuanha. U. S., Br

Ipecacuanha has already been treated of among the emetics and diaphoretics (II. 465 and G58). in nauseating doses, it acts, like other nauseants, in promoting expectoration in an excited state of the pulmonary circulation. Even in quantities insufficient to produce the sensation of nausea, it probably exerts a less degree of the same relaxing influence through the nervous centres. But there is reason to think that, through the absorption of its active principle, it operates also directly on the secretory function. By this double influence, it is one of the most certain and energetic expectorants, adapted to the early stage of inflammatory diseases of the air-passages and pulmonary air-cells. it is peculiarly suitable for children, from the comparative mildness of its irritant effect on the alimentary canal; being, on this account, often preferred to the antimonials, where these might otherwise be deemed more appropriate. in croup after an emetic, catarrh, measles, and the early stage of hooping-cough occurring in young children, it is much and beneficially used. After expectoration has become fully established, and the activity of the inflammation is passed, the medicine may often be usefully associated with small doses of one of the salts of morphia, or other preparation of opium, to allay cough; and, at an earlier period, the same end may be aimed at by the use of hyoscyamus, conium, or lactucarium, which do not, like opium, restrain the bronchial secretion.

The dose of it for an adult is from half a grain to two grains, repeated every two, three, or four hours, or less frequently, according to the severity of the case, and the degree of its nauseating effect. it should, as a general rule, be kept within the point of decided nausea. But the liquid preparations are much more used as expectorants than the root in powder.

Wine of ipecacuanha (Vinum ipecacuanhas, U.S., Br.) is made in the proportion of a troyounce of the root to a pint of wine; so that, if the root is exhausted, one fluidounce must contain the strength of thirty grains. From ten to thirty minims may be given as an expectorant to an adult. The British wine is about one-third weaker than that of the U.S. Pharmacopoeia, containing only about twenty grains to the fluidounce.

Fluid Extract of ipecacuanha (Extractum ipecacuanha Fluidum, U. S.) is prepared by exhausting the root with alcohol, concentrating the tincture to the consistence of syrup, then adding water to precipitate the resin, and acetic acid to give stability to the alkaloid, again concentrating, at a boiling temperature, filtering, and finally adding a certain measure of water and of alcohol, to give it a proper bulk and preserve it. A fluidounce represents an ounce of the root. The emetic dose is, therefore, from fifteen to thirty minims; the dose as an expectorant, one or two minims.

Syrup of ipecacuanha (Syrupus ipecacuanha, U. S), according to the U. S. process, is now made by simply mixing two fluidounces of the fluid extract with thirty of syrup. From two to ten minims may be given as an expectorant to children from one to four years old, from thirty minims to a fluidrachm to an adult.

Troches or Lozenges of ipecacuanha (Trochisci ipecacuanha, U. S.) are made by incorporating the powder with sugar and arrow-root by means of mucilage of tragacanth. The preparation is demulcent and expectorant, and is intended to be held in the mouth, and swallowed as it slowly dissolves. Bach lozenge contains about one-quarter of a grain of ipecacuanha. A little of one of the salts of morphia may sometimes be usefully combined with the other ingredients; and the British Pharmacopoeia directs a preparation of this kind (Trochisci Morphia et ipecacuanha, Br.), of which each lozenge contains about one thirty-sixth of a grain of muriate of morphia, and about one-twelfth of a grain of ipecacuanha.