ing that of boiling water, it is essential that the temperature prescribed in the official process of manufacture be not exceeded. Evaporation of the infusion at a low temperature in a vacuum apparatus is always to be preferred, the average yield being about 60-65 per cent. of extract. Extract of malt is a brown-yellow thick liquid or semifluid mass, having a slight peculiar odor, a sweet taste, and an acid reaction toward litmus paper.

The diastasic value of extract of malt is determined by its power of converting starch into dextrose, and the following method may be employed for comparative testing of different malt extracts, that extract capable of converting the largest amount of starch within a given time, under like conditions, being considered the best: Dissolve 5 Gm. of extract of malt in sufficient distilled water to yield. 100 Cc. of solution; of this, add 5 Cc., representing 0.25 Gm. of the extract, to 250 Cc. of cold starch mucilage (prepared by dissolving 30 Gm. of Bermuda arrowroot in 1000 Cc. of boiling distilled water) and keep the mixture at a temperature of 55° to 60° C. (131°-140° F.) for 30 minutes; then stop the diastasic action by raising the temperature to 100° C. (212° F.) or by addition of 2 or 3 Cc. of a 10 per cent. sodium hydroxide solution, and dilute the mixture to a given volume by addition of water. Titrate an aliquot part of the liquid with Fehling's Solution (alkaline cupric tartrate volumetric solution, U. S. P.) and ascertain the amount of dextrose present, from which deduct the amount found in a corresponding amount of the extract of malt by previous titration with Fehling's Solution; the difference indicates the amount of sugar produced by the diastase present in the extract. Each Cc. of Fehling's Solution corresponds to 0.005 Gm. of anhydrous dextrose, or 0.0045 Gm. of starch converted thereinto.

Extractum Nucis Vomicæ; Extract of Nux Vomica.-The object of exhausting the drug with 10 per cent. acetic acid is to avoid extraction of the fixed oil present in the seed, the subsequent removal of which before the extract can be powdered, is a tedious operation. A coarse powder is preferable in order to avoid impaction of the mass, since under the influence of the watery menstruum the powder rapidly swells. Unfortunately the acetous menstruum also extracts considerable inert matter, which by increasing the yield of dry extract may render the standardization of the powder impossible, or at least difficult, because the larger the yield of extract, the smaller must be the percentage of alkaloids in the same. In the author's experience from 35 to 40 per cent. of dry extract has been obtained by exhausting nux vomica with the official menstruum; and assuming the average strychnine content of prime nux vomica to be 1.5 per cent., such an extract would contain from 3.75 to 4.22 per cent. of strychnine and allow no addition of diluent to preserve the pulverulent condition, being already below the prescribed standard. The Pharmacopoeia therefore very properly directs that the concentrated liquid shall be diluted with 3 times its volume of alcohol, whereby the inert matter extracted by the acid menstruum is pre

cipitated, the hydro-alcoholic liquid retaining the alkaloids present in solution as acetates. After washing the precipitate thoroughly with a mixture of alcohol and water, as prescribed, the solution is evaporated to dryness and a small quantity of the powdered extract is assayed; from the results obtained the quantity of sugar of milk is calculated necessary to add to the remainder of the powder, so that the finished product shall contain the prescribed amount of strychnine, namely 5 per cent.

Thus, if 2 Gm. of the powdered extract should be found to contain 0.130 Gm. of strychnine, or 6.5 per cent., then each Gm. of the remaining powder requires the addition of 0.300 Gm. of sugar of milk to reduce the strength to that of the official standard of 5 per cent., for 0.05: 0.065: 1: x (x=1.300), where x represents the weight of official extract corresponding to 1 Gm. of the extract assayed. Then 1.300-1=0.300 in grammes.

Powdered extract of nux vomica is very susceptible to moisture and heat, and readily cakes unless preserved in tightly stoppered bottles in a cool, dry place. The present extract is weaker than that formerly official, which latter contained 15 per cent. of total alkaloids and since the proportion of strychnine present in the total alkaloids varies from 45 to 55 per cent., this would correspond to from 6.75 to 8.25 per cent. of strychnine, as compared with the present official standard of 5 The British extract of nux cent. per vomica is of pilular consistence, but of the same strychnine content

as our own.

Extractum Opii; Extract of Opium.-Opium is easily exhausted with cold water, but instead of triturating the mixture of opium and water occasionally during twelve hours, it is better to rub the opium into a smooth paste with water in a mortar, wash this carefully into a flask or bottle, add the remainder of the water, cork the flask or bottle, and shake vigorously every hour or two; agitation is more easily accomplished and is more beneficial to the extraction of the soluble principles. The magma on the filter should be slowly percolated with water until the liquid is nearly colorless and only faintly bitter. After concentration of the percolate to about twice the weight of opium used, the moisture and morphine present are determined, in order to ascertain the amount of sugar of milk which must be added to the syrupy extract, so that, upon complete drying, it shall yield a powder containing 20 per cent. of crystallized morphine.

Suppose the thick syrupy liquid is found to contain 72 per cent. of moisture and to yield 7 per cent. of crystallized morphine: then each Gm. of the liquid will require the addition of 0.07 Gm. sugar of milk, so that when evaporated to dryness and powdered the extract shall contain the prescribed quantity, 20 per cent., of morphine, as shown by the following calculation: As the syrupy liquid contains 72 per cent. of moisture, 100 Gm. will yield 100-72, or 28, Gm. of dry extract, and the original morphine content of 7 per cent. (or 7 Gm. in 100 Gm.) will be increased to 25 per cent. in

the dry extract, because no morphine is lost, and 7 Gm. is 25 per cent. of 28 Gm. Now, according to the rule for adjustment of percentages, given on page 73, multiply the given quantity by the given percentage and divide by the required percentage, or 28×25 = 700, and 70020-35: hence the 28 Gm. of dry extract, representing 100 Gm. of the syrupy liquid, will yield 35 Gm. of powdered extract of the official standard, yielding 20 per cent. of crystallized morphine. The difference, then, between 28 Gm. and 35 Gm. (or 7 Gm.) is the quantity of sugar of milk required for 100 Gm. of the syrupy liquid, or 0.07 Gm. for 1 Gm.

20

Proof: 1 Gm. of the syrupy liquid yielding 0.07 Gm. of crystallized morphine, when mixed with 0.7 Gm. of sugar of milk, upon evaporation to dryness will yield 0.35 Gm. of dry extract still containing the original quantity of morphine (0.07), and 0.07 Gm. is per cent., or, of 0.35 Gm., for 0.07 divided by 0.35=0.20. Extractum Physostigmatis; Extract of Physostigma, also known as Extract of Calabar Bean.-Like all seeds, physostigma contains considerable fat, which is extracted by the alcoholic menstruum, and hence it is not possible to produce a perfect pilular or powdered extract without the addition of some diluent. While sugar of milk, if added, produces a good pilular mass, as directed in the British Pharmacopoeia, powdered licorice root is a better absorbent and yields quite a fair powdered extract. The Pharmacopoeia requires that the finished extract shall contain 2 per cent. of ethersoluble alkaloids, and if the extract is found to contain a larger proportion of the alkaloids, sufficient finely powdered licorice root must be added to reduce the strength to the official standard. The necessary quantity of licorice root to be added to each Gm. of the dry extract may be found by the same method of calculation as given under Extract of Nux Vomica.

Extractum Quassiæ; Extract of Quassia.-Owing to the tendency of this extract, if in pilular condition, to become tough in the course of time, it seems preferable to have it in the powder form; and since the yield of extract obtained by exhausting quassia with cold water is small, rarely above 4 per cent., the Pharmacopoeia directs dilution with sufficient sugar of milk so that the finished product shall represent 10 times its weight of the crude drug. In this condition the extract is well adapted for all purposes, is perfectly soluble in water, and keeps well.

Extractum Rhamni Purshianæ; Extract of Cascara Sagrada. Although cold water is capable of extracting all the medicinal virtues of cascara sagrada bark, a weak alcoholic (about 12 per cent.) menstruum is preferred, so as to avoid fermentative changes during the prolonged maceration and percolation, especially in warm weather. The yield of dry extract varies from 20 to 22 per cent., and after admixture with sufficient powdered licorice root, so that the finished product shall represent 4 times its weight of the crude drug, the powdered extract keeps well.

Extractum Rhei; Extract of Rhubarb.-When the official fluidextract of rhubarb is evaporated to dryness it yields from 35 to 42 per cent. of residue, which can easily be reduced to powder, and keeps admirably if mixed with sufficient powdered licorice root to represent twice its weight of the crude drug. Such a powdered extract corresponds very nearly to the yield of pilular extract obtainable from the fluidextract directed by the Pharmacopoeia and is preferable to the latter for dispensing purposes, since the pilular extract is apt to become tough and dry with age unless some glycerin be incorporated with it.

Extractum Scopola; Extract of Scopola.-This extract, which is practically identical in composition and medicinal effects with an extract made from belladonna root, is officially recognized for the purpose of permitting its use in plasters. The yield of extract in pilular form is about 16 to 20 per cent. and the Pharmacopoeia requires that it shall contain 2 per cent. of mydriatic alkaloids, to be determined by titration with volumetric acid solution. If the extract be found to be above the prescribed strength, sufficient powdered sugar of milk must be added to reduce it to the official standard. The necessary quantity of sugar of milk can be found by calculation, as explained under Extract of Belladonna Leaves.

Extractum Stramonii; Extract of Stramonium.-Since the leaves are the only part of the stramonium plant officially recognized, the present extract is rich in green coloring-matter. It is prepared like extract of hyoscyamus, but is required to contain 1.0 per cent. of alkaloids, to be determined by titration with volumetric acid solution. If found to be above the prescribed strength, it must be mixed with sufficient powdered sugar of milk to reduce it to the official standard. The average yield of extract of stramonium leaves is about 20 per cent. On account of the large proportion of resinous matter in the leaves it is essential that the fluidextract be constantly stirred during evaporation, especially toward the end of the operation, otherwise a granular product may result from the separation of resin as the alcoholic strength of the liquid changes.

Extractum Sumbul; Extract of Sumbul.-It is impossible to obtain a perfect pilular extract, in the case of sumbul, on account of the peculiar nature of the resin and oil present in the root. yield of extract is about 15 per cent.

The

Extractum Taraxaci; Extract of Taraxacum, also known as Extract of Dandelion.-Although this extract was formerly directed to be prepared by expression and evaporation of the juice of the root freshly gathered, it is doubtful whether this plan was followed to any great extent, and, moreover, no provision was made for the removal of the starchy and albuminous constituents of the juice. The exhaustion of the ground taraxacum with a weak alcoholic (about 12 per cent.) menstruum insures a complete extraction of the medicinal virtues, without much inert matter, the resulting extract yielding a nearly clear solution with water. Absence of a bitter taste in the last portions of the percolate indicates complete exhaustion of the drug.

CHAPTER XXIV.

OLEORESINS AND RESINS.

OLEORESINS.

SOLUTIONS of this class represent the medicinal virtues of the drugs from which they are made, in a more concentrated form than is possible in any other. They possess the power of self-preservation, and in this respect are superior to fluidextracts. Oleoresins consist chiefly of fixed or volatile oils associated with resin and other constituents; those officially recognized, with one exception, are all prepared by the same process, which consists in slowly percolating the drug in fine powder, with acetone, to exhaustion, recovering the greater part of the acetone by distillation, and finally removing the remaining acetone by spontaneous evaporation. The percolation of drugs with acetone requires the use of special apparatus (see page 134) to prevent loss of the volatile solvent, and several attempts have been made to economize menstruum by repeatedly using the same liquid until the material is exhausted, the best device for this purpose being the ether extraction apparatus designed by Prof. Flückiger, illustrated in Fig. 215. The extractor A passes by means of the tube D through a cork into the receiving flask E; at C is a septum or disk, upon which the material to be extracted is packed, and which communicates by means of a small funnel-shaped tube with D. The lateral tube BF passes into the tube G, which is provided with a properly cut cork, K, so that the acetone vapor may pass from the receiving bottle to a spiral condenser, H, fitted by means of a cork to the top of the extractor; the acetone vapor can also be made to pass upward through the powder by pushing the cork deeper into the tube G, thus closing the orifice of the lateral tube BF. A loose pledget of cotton is placed in the funnel tube at C, or a piece of filter paper is placed over the small opening to prevent the material from passing down. The whole apparatus may be made of any convenient size, of glass or tinned copper, and when in use the receiving flask is placed in warm water, for the purpose of vaporizing the acetone, which is condensed above the extractor and drops back upon the powder, the process being continued until the material is exhausted. Another desirable feature of this apparatus is the recovery of the acetone from the mare when the extraction of the drug has been completed. The lateral communication between D and BF is closed by means of the cork, and, applying a cold