ing to the equation e, that the syrup is of proper strength (10 per cent.).

Exercise. Two grammes of a sample of Syrup of Ferrous Iodide were titrated. First, 12 Cc. of decinormal silver nitrate V. S. were added, and afterward 3 Cc. of decinormal potassium sulphocyanate V. S. were required, until the solution assumed a red-brown color, ferric ammonium sulphate T. S. being used as indicator. What was the strength of the syrup?

=

Since 1 Cc. of the sulphocyanate V. S. is equivalent to 1 Cc. of the silver V. S., hence 9 Cc. (12 Cc. 3 Cc. 9 Cc.) of the silver solution were consumed by the ferrous iodide. Now, since 1 Cc. of decinormal silver nitrate V. S. is equivalent to 0.0154 Gm. of ferrous iodide, hence 9 x 0.01544 0.1389 Gm.; consequently the 2 Gm. of the syrup contain 0.1389 Gm., or 6.94 per cent. of ferrous iodide.*

Exercise.-How much ferrous iodide can be obtained from 83 Gm. of iodine?

Since, according to equation a, 253.2 parts of iodine yield 308.9 parts of ferrous iodide, 83 Gm. of iodine will yield 101.2 + Gm. of ferrous iodide, for

Thus 83 Gm. of iodine will yield 101.2 + Gm. of ferrous iodide.

*In a reaction of this kind the theoretical yield is never obtained, for moisture and impurities in the iodine will lower the results.

TABLE OF U. S. P. SYRUPS CLASSIFIED ACCORDING TO MODE OF

MELLITA-(Honeys).

The official Honeys are a class of thick or semi-liquid, sweet, medicated preparations, differing from syrups in that honey is employed as the base instead of simple syrup.

This class of preparations was formerly quite popular, but their number has been gradually lessened by the various pharmacopoeias, until at present Mel Despumatum and Mel Rosa constitute the only ones remaining. These two are employed simply as bases, or vehicles, for the administration of other remedies.

Great caution should be observed in the selection of honey for pharmaceutical purposes; for, because of its peculiar viscidity, it is easily adulterated with glucose.

MEL DESPUMATUM. - The U. S. Pharmacopoeia directs the strained honey to be clarified by heating it on a water-bath with paper pulp, as long as any scum (consisting of wax and other lighter impurities) rises to the surface. This is removed by skimming. Then, after straining, 5 per cent. of glycerin is added for the purpose of protecting the honey from any change. A more brilliant preparation is obtained if it be filtered through paper* in a steam-jacketed funnel ("Hot Filtration," page 179). Various other clarifying agents are in use and have been suggested, among which are gelatin, white of egg, Irish moss, animal charcoal, aluminum hydroxide, etc.; but all these require that the honey be diluted with water, necessitating therefore subsequent evaporation, which results in impairing the aroma and often the color of the honey.

OXYMELLITA.

These consist of simple or medicated honey mixed with acetic acid.

Oxymel of the British Pharmacopoeia consists of a mixture of clarified honey (40 oz.), acetic acid, and water (each 5 fl. oz.). Other pharmacopoeias direct that the honey be mixed with dilute acetic acid and evaporated. The simplest process is that of the Ph. Ger. I, which consists in mixing 40 parts of clarified honey with 1 part of acetic acid (sp. gr. 1.040). The most popular preparation of this class is the Oxymel Scillæ, which is made by mixing Vinegar of Squill with clarified honey.

*For filtering syrups, honey, oils, etc., Schleicher & Schüll's filter paper, Nos. 586 and 584, are especially adapted.

ELIXIRIA-(Elixirs).

ELIXIRS are sweetened, aromatic, hydro-alcoholic, medicated preparations.

The word "elixir" is derived from the Arabic iksir (itself derived from the Greek), a name applied by alchemists to a wonderful powder capable of transforming base metals into gold and silver. This term was later applied to compound tinctures which were supposed to possess rare medicinal virtues. In modern times, this title was applied in European countries to concentrated alcoholic extracts of drugs usually of disagreeable taste. Later, in American pharmacy, it has been applied to an entirely different class of preparations, characterized by their pleasant aromatic taste and containing from 20 to 25 per cent. of alcohol.

The objection to these preparations is that, owing to the small percentage of medicinal agent present, the dose is necessarily large, the alcohol present often seriously interfering with the medicinal action of the drug.

The U. S. Pharmacopoeia recognizes Elixir Aromaticum, which is employed simply as an aromatic flavoring agent, and Elixir Phosphori, each cubic centimeter of which represents 0.00025 Gm. of phosphorus, corresponding to about of a grain in each teaspoonful.

GLYCERITA-(Glycerites).

GLYCERITES are solutions of medicinal agents in glycerin. Glycerin, because of its valuable solvent properties and freedom. from rancidity, forms an excellent vehicle for the external application of many organic and inorganic substances.

Glycerin not only effectually protects sensitive compounds from oxidation and change, but also affords permanent elegant solutions which form emollient and soothing applications. Such concentrated solutions as those of carbolic, tannic, and gallic acids, etc., are very convenient, because they readily yield clear solutions on dilution with water. recognizes 6 glycerites. The U. S. Pharmacopoeia