Mix them by agitation in a bottle, which should be well stoppered. This Liniment should be freshly prepared, when wanted.

Dissolve the Camphor in about 200 C.c. [old form 63 fl. oz.] of the Fluid Extract, and then add enough of the latter to make the product measure 1000 C.c. [old form 2 pints]. Mix thoroughly.

Introduce the Camphor and the Cotton Seed Oil into a suitable flask, and apply a gentle heat, by means of a water-bath, loosely stoppering the flask during the operation. Agitate from time to time, until the Camphor is dissolved.

Introduce the Camphor and the Alcohol into a suitable bottle, and shake until the Camphor is dissolved. Then add the Soap and Oil of

Rosemary, and shake the bottle well for a few minutes. Lastly, add enough Water to make 1000 C.c. [old form 2 pints], and again shake until the liquid becomes clear. Set it aside, in a cool place, for twentyfour hours, then filter.

LINIMENTUM SAPONIS MOLLIS. U. S. Liniment of Soft Soap. [TINCTURA SAPONIS VIRIDIS, PHARM. 1880.]

Mix the Oil of Lavender with the Alcohol, dissolve in this the Soft Soap by stirring or agitation, and set the solution aside for twenty-four hours. Then filter it through paper, and pass enough Water through the filter to make the product measure 1000 C.c. [old form 2 pints]. Mix thoroughly.

Dissolve the Camphor in 500 C.c. [old form 8 fl. oz.] of Alcohol, and add the Fluid Extract of Mezereum; then add the Oil of Mustard and the Castor Oil and, finally, enough Alcohol to make the product measure 1000 C.c. [old form 1 pint]. Mix thoroughly.

Melt the Resin Cerate in a capsule, on a water-bath, then add the Oil of Turpentine, and mix them thoroughly.

Oleata. Oleates.

The official oleates are liquid preparations made by dissolving metallic salts or alkaloids in oleic acid. The term oleate is also used commercially to designate solid preparations which are supposed to be chemical compounds of oleic acid with various bases. (See Part V.)

The official oleates are not assumed to be definite chemical compounds. The proportion of oleic acid is excessive, and they must be regarded as solutions of the medicating agent in oleic acid, the latter having special advantages as a basis for administering external remedies, being more readily absorbed than most of the fatty substances used in making ointments. Three oleates are official.

Introduce the Oleic Acid into a capacious mortar, and gradually add to it the Yellow Mercuric Oxide by sifting it upon the surface of the Acid, and incorporate it by continuous stirring. Then set the mixture aside in a warm place, at a temperature not exceeding 40° C. (104° F.), and stir frequently, until the Oxide is dissolved.

Rub the Veratrine with a small quantity of Oleic Acid, in a warm mortar, to a smooth paste. Then add the remainder of the Oleic Acid, previously warmed, and stir frequently, until the Veratrine is dissolved.

Introduce the Oleic Acid into a capacious capsule, and gradually add to it the Zinc Oxide by sifting it upon the surface of the Acid, and incorporate it by continuous stirring. Set the mixture aside for a few hours, and then heat it on a water-bath, frequently stirring, until the Oxide is dissolved.

QUESTIONS ON CHAPTERS XXIV. AND XXV.

ETHEREAL SOLUTIONS, OLEAGINOUS SOLUTIONS OR EXTERNAL APPLICATIONS.

What are collodions, and how are they used?
How many are official, and what are their names?
Give the formula and mode of making collodion.
What is the official name of cantharidal collodion?
Give its formula and mode of preparation.

What is flexible collodion?

Give its formula and mode of preparation.

What is styptic collodion?

Give its formula and mode of preparation.

What are liniments?

How many are official?

What substances are used as the bases for these liniments?

How is ammonia liniment made?

What is its popular name or synonyme?

Give the formula and mode of making belladonna liniment. Lime liniment. What is this sometimes called? Camphor liniment. Chloroform liniment. Soap liniment.

What kind of soap should be used?

What is the Latin name of liniment of soft soap?

What was its official name in the U. S. P. 1880?

How is it made?

Give the formula and mode of making compound liniment of mustard. Turpentine liniment.

What are official oleates?

How many are there, and what are their names?

What advantage are they supposed to possess over the fatty substances that are commonly used in ointments?

Give the formula and mode of making oleate of mercury. Oleate of veratrine. Oleate of zinc.

CHAPTER XXV I.

AQUEOUS LIQUIDS MADE BY PERCOLATION OR MACERATION.

Infusa. Infusions.

INFUSIONS are liquid preparations made by treating vegetable substances with either hot or cold water. The drug is not subjected to the boiling process, although it is common to pour boiling water over it; the whole is allowed to stand in a close vessel until cold. Whilst the use of hot water has the advantage of saving time in some cases, it is often objectionable because the inert principles in the drug are dissolved by the hot water, and as the infusion cools, they are precipitated out in such a very finely divided condition that they cannot be readily separated by colation or filtration. Cold water should be selected as the menstruum when the drug contains a valuable volatile principle, when the active agent is injured by heat, or when the desirable principles are readily soluble in water of ordinary temperature. The time required to make the infusion must be considered, for in warm weather it is quite possible for an infusion to ferment or decompose before it is finished.

Pure water should be used in making infusions, and large quantities should not be made at one time unless demanded for immediate use, as, without special precautions to preserve them, they soon become decomposed.

Of the inert principles found in plants, starch is extracted by hot water and albumen by cold water, whilst gum, sugar, and extractive are dissolved by both.

In making infusions the drug is usually coarsely comminuted, sliced, or bruised. Fine powders should be avoided whenever possible, because it is difficult to separate the fine particles from the infusion; and if percolation is resorted to, so much time is consumed in the operation, owing to the swelling of the powder, that decomposition may set in before the preparation is finished. The number of official infusions is four. Infusions are usually made in four ways: 1. By maceration. 2. By digestion. 3. By percolation. 4. By diluting fluid extracts.

1. By Maceration. This is the process which is most frequently used. The general formula of the U.S. Pharmacopoeia, which is here appended, furnishes a model.

GENERAL OFFICIAL FORMULA FOR INFUSIONS.

An ordinary Infusion, the strength of which is not directed by the physician, nor specified by the Pharmacopoeia, shall be prepared by the following formula: