antimony and potassium tartrate and the active principles of 0.080 Gm. each of squill and senega.

23. Syrupus Senega. Syrup of senega is made by dissolving sugar in fluid extract of senega previously diluted with water. Senega is rich in pectin compounds, the separation of which, in liquid preparations of the drug, is avoided by the presence of alkalies. Fluid extract of senega contains 5 per cent. of ammonia water, and the Pharmacopoeia recommends a further addition of 21 per cent., before diluting the fluid extract with water. The mixture is filtered after standing three or four hours, and in the clear filtrate the sugar is dissolved without heat. Each Cc. of the syrup represents 0.200 Gm. of senega.

There appears to be no objection to preparing the syrup as wanted, by mixing one volume of fluid extract of senega with four volumes of simple syrup, this mixture keeping equally as well as the former more tedious preparation.

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24. Syrupus Senna. The official process for making syrup senna consists in preparing a strong infusion of the leaves, mixing this with alcohol and oil of coriander, removing the precipitate by filtration, and in the filtrate dissolving the sugar without heat; each Cc. represents the virtues of 0.250 Gm. of senna.

Long-continued digestion of senna leaves at 60° C. (140° F.), as directed in the Pharmacopoeia, is of no advantage, as the cathartic principles can be extracted in less time, and long maceration brings an undesirable amount of gum into solution; digestion for six or eight hours is no doubt sufficient when followed by expression and a further treatment of the dregs on the strainer by percolation with hot water. Solution of the sugar in the clear liquid is greatly facilitated by placing a well-corked bottle, containing both, in a modererately warm water-bath and agitating frequently. The gummy matter is precipitated upon the addition of alcohol, and some time must be allowed for complete separation of the precipitate, otherwise subsequent filtration of the liquid will be difficult; the clear liquid is decanted and the remainder filtered, the filter being washed with water.

CHAPTER XVII.

MUCILAGES, HONEYS, AND GLYCERITES.

Mucilages.

THE preparations recognized in the Pharmacopoeia under this name are viscid adhesive liquids formed by solution of mucilaginous principles in water; with one exception they are unstable and readily undergo putrefactive changes in warm weather, hence they should be freshly prepared when wanted. The four official mucilages are those of acacia, sassafras pith, tragacanth, and elm.

Mucilago Acacia. The Pharmacopoeia recommends that acacia be washed with cold water before it is brought into solution, for the purpose of removing foreign matter often adhering to the outer surface. The official formula will produce quite a viscid liquid containing 34 per cent. of acacia, each Cc. representing 0.378 Gm. Owing to the fact that the solution of acacia becomes denser as it progresses, stirring or agitation of the mixture will be found somewhat difficult toward the end of the process, and solution can be more readily effected by what is known as circulatory displacement (see page 114), that is, the suspension of the washed acacia in the water, in a bag of loosely textured cloth, to be occasionally moved about in the liquid so that fresh portions of the water may continually displace the solution formed, and thus complete solution be more rapidly effected. Pieces of clear, white acacia should be selected for the mucilage, which, when made, should be preserved in completely filled bottles, in a cool place.

Mucilago Sassafras Medulla. Mucilage of sassafras pith is made by macerating the pith in cold water for three hours and then straining; the mixture should be kept in a covered vessel and occasionally stirred with a glass rod. Each Cc. represents 0.02 Gm. of sassafras pith.

Mucilago Tragacantha. The official directions for preparing mucilage of tragacanth are, to add the tragacanth to a boiling mixture of glycerin and water and then macerate for twenty-four hours, with frequent stirring; after the addition of more water, the mass is beaten to a uniform consistence and then forcibly expressed through muslin. Mucilage of tragacanth forms a somewhat opaque semi-liquid jelly containing 6 per cent. of tragacanth; the presence of 18 per cent. of glycerin prevents decomposition. Tragacanth is only partially soluble in water, but absorbs the latter and swells to a gelatinoid mass.

Mucilago Ulmi. Mucilage of elm, although still recognized in

the Pharmacopoeia, is but very rarely prepared by pharmacists; the official directions are to add 6 Gm. of bruised elm to 100 Cc. of water and digest for one hour, in a covered vessel, on a water-bath. Mucilage of elm, like that of sassafras pith, spoils very readily, and should be freshly made when wanted.

Honeys.

Clarified honey, or Mel Despumatum of the Pharmacopoeia, is prepared by mixing honey with 2 per cent. of its weight of paper-pulp and heating the mixture on a water-bath as long as any scum rises to the surface; the scum is carefully removed with a skimmer and sufficient distilled water added to restore loss by evaporation, after which the mixture is strained and 5 per cent. of its weight of glycerin is added to the strained liquid, for the purpose of better preservation.

Medicated honeys are simply mixtures of clarified honey with certain medicinal agents, and are, as a rule, prepared extemporaneously. Only one medicated honey is recognized in the Pharmacopoeia, namely, Mel Rosa, or honey of rose, which is made by mixing fluid extract of rose with clarified honey, in such proportion that the finished product shall contain the astringent virtues of 12 Gm. of rose petals in every 100 Gm.; this is about equal to a mixture of 12 Cc. of fluid extract of rose with 64 Cc. of clarified honey.

Glycerites.

This valuable class of preparations consists of solutions of the medicinal agents in glycerin; they are permanent and are readily miscible with water or alcohol. Of the official glycerites, five are liquid and one solid.

Glyceritum Acidi Carbolici. This glycerite is conveniently prepared by placing crystallized carbolic acid and glycerin together in a porcelain dish and warming the mixture on a water-bath until perfect solution is effected; each Gm. of the finished glycerite represents 0.20 Gm. of carbolic acid, which is equal to about 110 grains in one fluidounce.

Glyceritum Acidi Tannici. Although tannin is perfectly soluble in cold glycerin, the solution of so large a proportion as directed in the official glycerite is best effected by the aid of heat; contact with metallic vessels must be carefully avoided, and the tannin and glycerin should be intimately mixed with a glass rod before heat is applied. When solution is completed, a deep green, transparent liquid results, which should be strained, while still warm, through flannel or a pledget of cotton. Glycerite of tannin contains 20 per cent. of tannin, or about 0.300 Gm. in each Cc., which is equal to about 120 grains in one fluidounce.

Glyceritum Amyli. The official directions for preparing glycerite of starch are to stir 10 parts of starch with 10 parts of water and

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80 parts of glycerin, to a homogeneous mixture, and then apply a gradually increased heat until a translucent jelly is formed. As starch usually occurs in lumps, it is necessary to first rub it, in a mortar, into a fine powder, which should be transferred to a porcelain capsule, and then mixed with the water and glycerin, so as to avoid loss, which is unavoidable if the mixture be made in the mortar; heat must be applied cautiously and the mixture constantly stirred with a thick glass rod or a wooden spatula, to avoid scorching and consequent discoloration. The liquid gradually thickens as the heat is increased, and the entire disappearance of white spots indicates perfect solution. The high heat indicated in the official formula is necessary to effect the rupture of the starch granules, without which solution of the starch cannot take place; to insure uniform heating, wire gauze should invariably be interposed between the capsule and the flame. Glycerite of starch is hygroscopic, therefore it must be preserved in tightly closed jars, so as to avoid contact

with air.

Glyceritum Boroglycerini. The preparation of this glycerite involves first the production of boroglycerin, known also as boroglyceride or glyceryl borate, and secondly, the solution of this compound in glycerin. When boric acid and glycerin are heated together to about 150° C. (302° F.), chemical action sets in, water being given off, while a new compound, glyceryl borate, is formed, which upon cooling is obtained as a transparent, almost colorless and very hygroscopic mass; the mixture must be frequently stirred to break up the constantly forming film, and care must be observed that the heat prescribed be neither exceeded nor continued longer than necessary, so as to avoid a yellowish or brownish coloration. Thirty-one parts of boric acid and 46 parts of glycerin will unite to form 50 parts of glyceryl borate; hence in the official process the reaction is known to be complete when the weight of the mixture has been reduced to 500 Gm.; then, while still hot, an equal weight of glycerin is added and thoroughly incorporated, thus making a 50 per cent. solution of boroglycerin. Each Cc. contains about 0.683 Gm. of boroglycerin, which is equal to about 312 grains in a fluidounce.

Glyceritum Hydrastis. In the official process for glycerite of hydrastis, the finely powdered root is exhausted with alcohol by percolation, the resulting tincture mixed with water and the alcohol removed by distillation, in order to precipitate the resinous matter; after dilution of the residue with more water, the mixture is set aside for twenty-four hours and then filtered, the filter being washed with water. To the filtrate, an equal volume of glycerin is added and the whole thoroughly mixed. Each Ce. of the finished glycerite represents 0.500 Gm. of hydrastis, or a fluidounce contains about 228 grains.

According to Prof. Lloyd, the best results will be obtained if the official directions be modified to the extent that the alcoholic tincture, without the addition of water, be concentrated to a syrupy consistence

by distillation or otherwise, and then poured into ice-cold water equal in quantity to one-half the weight of drug used; the soft, oily, resinous matter separates readily and can be removed by filtration after a few hours' rest. The filtrate must be brought to a volume of 500 Cc. for every 1000 Gm. of drug operated upon, by washing the filter with cold water, after which the glycerin is added and the mixture shaken thoroughly.

This glycerite is chiefly intended to furnish a fluid preparation of hydrastis which shall be miscible with water in all proportions without precipitation.

Glyceritum Vitelli. Glycerite of yelk of egg, or glyconin, is a mixture of 45 parts of yelk of egg and 55 parts of glycerin, of about the consistence of honey, which will keep for a long time if preserved in well-stoppered bottles, so as to prevent the absorption of moisture from the air. In order to obtain a satisfactory preparation, the yelk of egg should be carefully separated from the albumen, and the membrane enclosing the yelk then ruptured, so that only the pure yelk may be weighed; the glycerin should be added gradually, with constant trituration.