Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 126

4. As the first formula, with the addition of a strong decoction of saffron, q. s. It gives a beautiful colour to soups, &c.

_Obs._ The above formulae are those actually employed by the houses most celebrated for their 'soluble cayenne.' The products are of the very finest quality, and are perfectly wholesome. We speak from an extensive experience in the manufacture. The spirit distilled from the essence forms a most suitable menstruum for making fresh essence or tincture of cayenne.

=Pepper, Cu'beb.= See CUBEBS.

=Pepper, Jamai'ca.= See PIMENTO.

=Pepper, Kit'chen.= See SPICE.

=Pepper, Long.= _Syn._ PIPERIS LONGI FRUCTUS, PIPER LONGUM (Ph. L. & E.), L. "The immature fruit (dried female spikes) of _Piper longum_, Linn."

(Ph. L.), or long-pepper vine. The spikes are about 1-1/2 inch in length, with an indented surface, and are of a dark-grey colour. In its general properties it resembles black pepper, but it is less aromatic, though equally pungent. Elephant pepper is merely a larger variety of this species. (Gray.) The root and stems, sliced and dried, form the 'pippula moola' of the East Indies. (Roxburgh.)

=Pepper, Red.= See CAYENNE.

=Pepper, White.= _Syn._ PIPER ALb.u.m, L. This is made by either soaking ordinary black pepper in a solution of common salt, until the outside skins are soft, and then rubbing them off in the hands, or by merely rubbing off the skins of the over-ripe berries that fall from the vines.

An inferior quality is made by bleaching black pepper with chlorine.

_Obs._ The use of white pepper instead of black is an instance of the sacrifices made to please the eye. Pure white pepper has only about 1-4th of the strength of pure black pepper, whilst it is nearly dest.i.tute of the fine aroma of the latter. It also contains a mere trace of piperina or piperine, one of the most valuable const.i.tuents of black pepper.

=PEP'PER PODS.= Capsic.u.ms. See CAYENNE PEPPER.

=PEP'PERMINT.= _Syn._ MENTHA PIPERITA (Ph. L., E., & D.), L. "The recent and dried flowering herb of _Mentha piperita_" (Ph. L.), or garden peppermint. The flavour and odour of this herb are well known. It is the most pleasant and powerful of all the mints. Peppermint water and the essential oil have long been employed in nausea, griping, flatulent colic, hysteric, diarrha, &c.; but in regular practice chiefly to cover the taste of nauseous medicines, or as an adjunct or vehicle for more active remedies. See OILS (Volatile), WATERS, &c.

=PEP'SIN.= _Syn._ GASTERACE, CHYMOSIN. A peculiar principle found in the gastric juice, and which, in conjunction with hydrochloric acid, also present in the stomach, confers upon it the power of digesting certain portions of the food, and of dissolving, as Tuson has shown, calomel and other mineral substances.

_Prep._ 1. (Beale, 'Med. Times & Gaz.,' February 10th, 1872, p. 152.) "The mucous membrane of a perfectly fresh pig's stomach is carefully dissected from the muscular coat, and placed on a flat board. It is then lightly cleansed with a sponge and a little water, and much of the mucus, remains of food, &c. carefully removed. With the back of a knife, or with an ivory paper-knife, the surface is sc.r.a.ped very hard, in order that the glands may be squeezed and their contents pressed out. The viscid mucus thus obtained contains the pure gastric juice with much epithelium from the glands and surface of the mucous membrane. It is to be spread out upon a piece of gla.s.s, so as to form a very thin layer, which is to be dried at a temperature of 100 over hot water, or _in vacuo_ over sulphuric acid.

Care must be taken that the temperature does not rise much above 100 F., because the action of the solvent would be completely destroyed. When dry the mucus is sc.r.a.ped from the gla.s.s, powdered in a mortar, and transferred to a well-stoppered bottle. With this powder a good digestive fluid may be made as follows:

Of the powder 5 grains.

Strong hydrochloric acid 18 drops.

Water 6 ounces.

Macerate it at a temperature of 100 for an hour. The mixture may be filtered easily, and forms a perfectly clear solution very convenient for experiment.

"If the powder is to be taken as a medicine, from two to five grains may be given for a dose, a little diluted hydrochloric acid in water being taken at the same time. The pepsin powder may be mixed with the salt at a meal. It is devoid of smell, and has only a slightly salt taste. It undergoes no change if kept perfectly dry, and contains the active principle of the gastric juice almost unaltered.

"The method of preparing this pepsin was communicated to Mr Bullock, of the firm of Messrs Bullock and Company, 3, Hanover Street, Hanover Square, who at once adopted it for the preparation of medicinal pepsin, and soon improved upon it in some particulars. The dose is from 2 to 4 or 5 grains.--_Test._ 4/5ths of a grain of this pepsin, with 10 drops dilute hydrochloric acid and an ounce of distilled water, dissolve 100 grains of hard-boiled white of egg in from twelve to twenty-four hours. In the body probably twice this quant.i.ty of white of egg or even more would be dissolved in a comparatively short s.p.a.ce of time. The digestive powder prepared from the pig's stomach retains its activity for any length of time if kept dry. I had some which had been kept in a bottle for upwards of five years, and still retained its active power unimpaired. The solution made with this pepsin and hydrochloric acid was nearly tasteless and inodorous. One pig's stomach, which costs sixpence, will yield about 45 grains of the powder prepared as above described.

"Gradually the usefulness of this preparation of pepsin of the pig was found out, and it had to be prepared in increasing quant.i.ties. I should be afraid to say how many pigs' stomachs have been used of late years during the winter season.

"In 1857 Dr. Pavy carefully examined the pepsin prepared and sold by many different firms, and found that this dried mucus of the pig's stomach was the most active of them all ('Medical Times and Gazette,' 1857, vol. i, p.

336). In 1870 Professor Tuson inst.i.tuted a still more careful comparative examination, and with a similar result ('Lancet,' August 13th, 1870); for he found that this preparation was _twenty-five times stronger than some others that he obtained for examination_."

2. (Scheffer, 'Pharm. Journ.,' March 23rd, 1872, p. 761.) "Of the well-cleaned fresh hog stomach the mucous membrane is dissected off, chopped finely and macerated in water acidulated with muriatic acid for several days, during which time the ma.s.s is frequently well stirred. The resulting liquid, after being strained, is, if not clear, set aside for at least twenty-four hours in order to allow the mucus to settle. To the clarified liquid the same bulk of a saturated solution of sodium chloride is added, and the whole thoroughly mixed. After several hours the pepsin, which, by the addition of chloride of sodium, has separated from its solution, is found floating on the surface, from whence it is removed with a spoon and put upon cotton cloth to drain; finally it is submitted to strong pressure, to free it as much as possible from the salt solution.

"The pepsin, when taken from the press and allowed to become air-dry, is a very tough substance, and presents, according to thickness, a different appearance, resembling in thin sheets parchment paper, and in thick layers sole leather; its colour varies from a dim straw yellow to a brownish yellow. Besides a little mucus, it contains small quant.i.ties of phosphate of lime and chloride of sodium, which, however, do not interfere with its digestive properties, as they are found also in normal gastric juice.

"In order to get a purer article I redissolve the pepsin, as obtained after expression, in acidulated water, filter the solution through paper and precipitate again with a solution of sodium chloride; the precipitate, after draining and pressing, is now free of phosphate of lime and mucus, but still contains salt. In the freshly precipitated state the pepsin is very readily soluble in water, and cannot therefore be freed from adhering salt by was.h.i.+ng.

"By allowing the pressed sheet of pepsin to get perfectly air-dry--whereby it becomes coated with a white film and small crystals of chloride of sodium--and by immersing it then in pure water for a short time, the greater part of sodium chloride can be extracted, but it has to be done very rapidly, as the pepsin swells up considerably and loses its tenacity. By operating in this matter I have obtained a pepsin which dissolves in acidulated water to quite a clear colourless liquid, but as it still contains traces of salt, I prefer to call it purified pepsin."

3. (B. Ph.) A preparation of the mucous lining of a fresh and healthy stomach of the pig, sheep, or calf. The stomach of one of these animals, recently killed, having been cut open and laid on a board with the inner surface upwards, any adhering portions of food, dirt, and other impurity, are to be removed and the exposed surface slightly washed with cold water; the cleansed mucous membrane is then to be sc.r.a.ped with a blunt knife or other suitable instrument, and the viscid parts thus obtained is to be immediately spread over the surface of gla.s.s or glazed earthenware, and quickly dried at a temperature not exceeding 100 F. the dried residue is to be reduced to powder, and preserved in a stoppered bottle.--_Dose_, 2 to 5 grains.

=Pepsin, Saccharated.= To work it into saccharated pepsin ('American Journal of Pharmacy,' January, 1871) the damp pepsin, as it is taken from the press, is triturated with a weighed quant.i.ty of sugar of milk to a fine powder, which, when it has become air-dry, is weighed again, the quant.i.ty of milk sugar subtracted, and so the amount of pepsin found. The strength of this dry pepsin is now ascertained by finding how much coagulated alb.u.men it will dissolve at a temperature of 100 F. in five or six hours, and after this sufficient milk sugar is added to result in a preparation of which ten grains will dissolve one hundred and twenty grains of coagulated alb.u.men, and this preparation I have called saccharated pepsin.

=Pepsin with Starch.= Pepsin mixed with starch is the _medicinal Pepsine_ of M. Boudault; the _Poudre nutrimentive_ of M. Corvisart.

=PERCENTAGE.= Literally, "by the hundred." In commerce the term is applied to an allowance duty or commission on a hundred. (WEBSTER.)

=PERCHLO"RATE=, _Syn._ PERCHLORAS, L. A salt of perchloric acid.

The perchlorates are distinguished from the chlorates by their great stability, and by not turning yellow when treated with hydrochloric acid.

Like the chlorates, they give off oxygen when heated to redness. They may be prepared by directly neutralising a solution of the acid with a solution of the base. See POTa.s.sIUM (Perchlorate of), and CHLORINE.

=PERCHLO"RIC ACID.= See CHLORINE.

=PERCOLA'TION= _Syn._ METHOD OF DISPLACEMENT. A method of extracting the soluble portion of any substance in a divided state, by causing the menstruum to filter or strain through it. The 'sparging' of the Scotch brewers is an example of the application of this principle on the large scale. In _pharmacy_, the 'method of displacement' is frequently adopted for the preparation of tinctures, infusions, &c., and is, in some respects, superior to digestion or maceration. "The solid materials, usually in coa.r.s.e or moderately fine powder, are moistened with a sufficiency of the solvent to form a thick pulp. In twelve hours, or frequently without delay, the ma.s.s is put into a cylinder of gla.s.s, porcelain, or tinned iron, open at both ends, but obstructed at the lower end by a piece of calico or linen, tied lightly over it as a filter; and the pulp being backed by pressure, ranging as to degree with different articles, the remainder of the solvent is poured into the upper portion of the cylinder, and allowed gradually to percolate. In order to obtain the portion of the fluid which is absorbed by the residuum, an additional quant.i.ty of the solvent is poured into the cylinder, until the tincture which has pa.s.sed through equals in amount the spirit originally prescribed. The spirit employed for this purpose is then recovered, for the most part, by pouring over the residuum as much water as there is spirit retained in it, which may be easily known by an obvious calculation in each case. The method of percolation is now preferred by all who have made sufficient trial of it to apply it correctly." (Ph. E.)

The first portion of liquid obtained by the method of displacement is always in a state of high concentration. In general it is a simple solution of the soluble ingredients of the crude drug in the fluid employed. But sometimes the solvent, if compound, is resolved into its component parts, and the fluid which pa.s.ses through at any given time is only one of these, holding the soluble parts of the drug in solution. Thus if diluted alcohol be poured over powder of myrrh, in the cylinder of the percolator, the fluid which first drops into the receiver is a solution of an oily consistence, chiefly composed of resin and volatile oil, dissolved in alcohol. In like manner, when the powder of gall-nuts is treated in the same way by hydrated sulphuric ether, two layers of fluid are obtained, one of which is a highly concentrated solution of tannin in the water of the ether, and the other a weak solution of the same principle in pure ether. In all cases, therefore, in which it is not otherwise directed it is absolutely necessary to agitate the several portions of the liquid obtained by percolation together, in order to ensure a product of uniform strength or activity.

Several forms of displacement apparatus are employed by different operators. A simple and useful one is that figured in the margin. It has also the advantage of being inexpensive, and may be made by any worker in tin plate.

In operating on some substances it is found advantageous to hasten the process by pressure. This may be effected by any of the methods adopted for that purpose, and already described under FILTRATION. An ingenious little apparatus, which is well adapted for small quant.i.ties, is shown in the _engr._ By pouring mercury or water through (_e_), into the bottle (_c_), the air in the latter suffers compression, and acts in a corresponding manner on the percolating liquor in (_a_). The whole of the joints must be made air-tight.

[Ill.u.s.tration: _a._ Percolator.

_b._ Stand.

_c._ Receiver.

_d._ Menstruum.

_e._ Substance operated on.

_f._ Calico strainer.]

[Ill.u.s.tration: _a._ Percolator.

_b._ Tube connecting; it with--

_c._ A double-necked bottle containing--

_d._ Mercury.

_e._ Feeding-tube.

_f._ Receiver.