Ipomoea Jalapa. Jalap.

Description: Natural Order, Convolvulaceae. Genus IPOMEA: Sepals five; corolla campanulate; stamens included, style one. Fruit a two-celled and two-seeded capsule. I. JALAPA: Stem round, smooth, very long, twining to great heights around neighboring objects. Leaves entire, smooth, acutely pointed, heart-shaped, lower ones somewhat hastate. Flowers large, lilac-purple, two or three from the same long peduncle; calyx five-sepaled, without bracts; corolla funnel-form.

This plant is found abundantly in Mexico, upon the high table-lands. The root is fleshy and tuberous, somewhat pear shaped, with numerous long fibers, dark colored without and grayish- white within, varying in diameter from half an inch to three incites. Sometimes the tubers come to market whole, deprived of their fibers; but generally they arc cut into horizontal slices, or else split lengthwise. The tuber, when dry, is hard, heavy, brittle, with a somewhat shining fracture, and dark circle's among the grayish-white substance. It is of a sweetish taste, which passes away and leaves an acrid and disagreeable sensation in the mouth. It contains a large portion of resinous material, which may be discerned with a good glass in points upon the fractured surface. This resin consists of two kinds, one of which (rhodeoretin) is hard, soluble in alcohol, slightly soluble in water, insoluble in ether, and is the active cathartic principle of the root. The other resin is soft, and is soluble in ether. It contains a larger percent of medicinal extractive than of resin. It imparts a portion of its properties to water, and a portion to alcohol; but alcohol of seventy percent acts most effectually upon it as a menstruum.

By long keeping, jalap becomes spongy, and seems to undergo changes which are largely destructive of its properties. Worms often attack it, but do not destroy the resin; whence a worm-eaten article may be more purgative, in a given weight, than one not thus attacked.

Properties and Uses: The root of jalap is an active cathartic, relaxing to a moderate extent, but most largely stimulating. It acts principally upon the mucous surfaces of the bowels, procuring prompt and thin stools, and even proving drastic in large doses. It stimulates the gall-ducts some, and also the muscular fibers of the bowels–whence it frequently proves griping. An average dose commonly operates in from three to four hours. By being sprinkled upon an ulcerous surface, it will be absorbed and procure catharsis. It is best given in depressed conditions of the bowels and atonic congestions of the portal circle; but is not a suitable agent for irritable states of the stomach and alvine canal; and bilious or leuco-phlegmatic temperaments can use it to much better advantage than the nervous. It is oftenest given in powder, of which the average dose is from ten to twenty grains; and it is rare for more than fifteen grains to be required. If treated by alcohol, the tincture is exceedingly griping; which shows the harsher qualities of the agent reside in the resinous portion. An infusion in warm water rarely gripes. If the dregs remaining from an alcoholic tincture be dried, and then treated with water, the infusion will scarcely act upon the bowels at all, but will make a pretty sharp stimulating and relaxing impression upon the kidneys. If moderate portions of the powder be given with such a diuretic as juniperus, the action on the bowels will be limited, but an intense diuretic influence will be obtained. (§262.) It is customary to combine the powder with aromatics. It is much abused by over-use–both alone and in compounds.

Pharmaceutical Preparations: I. Compound Powder. Anti-bilious Physic. Jalap, one pound; senna, two pounds; ginger, two ounces. Mix the powders. This makes an efficient cathartic where a quick action is required. It procures thin discharges, unloads the bowels of all accumulations, and is not harsh or griping. A suitable dose usually operates in less than three hours. Half a drachm may be given as a dose, mixed with two ounces of water and some sugar. Or it may be infused, and the clear liquor poured off and used. Some writers direct a drachm as a dose, but this is too drastic; and it is preferable to administer half a drachm, and then to give a second portion of about fifteen grains, if the first quantity does not procure an action (or premonitions of one) in two hours. Some practitioners use cloves instead of ginger, but this formula is not always acceptable to the stomach. Powdered peppermint was at first employed with cloves in this compound, but this made the dose very bulky. Many practitioners add about ten grains of cream of tartar to each dose–which increases its promptness and efficiency. This powder is so effectual, that it has come to be prescribed almost as a routine by some physicians, without due discrimination as to where it should and should not be used.

II. Extract. This is prepared by first treating the coarsely-powdered jalap with diluted alcohol, and afterward with cold water, in the percolator; then mixing the two products and evaporating to a solid mass. In the soft state, it is used as a basis for cathartic pills; but may be dried and powdered. It contains both the resinous and extractive matters of the root, and is a good representative of the drug. Dose, from eight to fifteen grains. The hard extract is often mixed with an equal part of scammony and one-eighth part of ginger, for a cathartic powder.

III. Fluid Extract. Macerate one pound of crushed jalap with diluted alcohol; put in a percolator, and treat with diluted alcohol till half a gallon has passed; evaporate to one quart, and then add half a pound of sugar and half an ounce of carbonate of potassa, (which renders the jalap resin soluble in water;) then evaporate to twelve fluid ounces; and while hot, bottle and add four fluid ounces of alcohol. This formula was proposed by Prof. Proctor, and makes an efficient preparation. Dose, from fifteen to twenty drops.

IV. Resin of Jalap. This may be obtained in a moderately pure state by macerating any suitable quantity of well-crushed jalap with diluted alcohol, then transferring to a percolator and exhausting with diluted alcohol, afterward distilling off the spirit and evaporating the remainder over a steam-bath. It is dark colored and brittle; and purges actively in doses of from three to five grains. A pure resin, as white as starch, may be obtained by placing a layer of fine animal charcoal upon a diaphragm of flannel in the bottom of the percolator, mixing equal parts of jalap and animal charcoal and laying on this, adding absolute alcohol till enough passes to equal in weight the amount of jalap used, and precipitating the resin by adding to this tincture twice its own volume of water.

V. Tincture. Six ounces of crushed jalap are macerated for two weeks in a quart of diluted alcohol, expressed and filtered. It is very harsh, and is seldom used, except as an addendum to other cathartic mixtures. Jalap and senna are often tinctured together.

Jalap is sometimes mixed with twice its own weight of tartrate potassa, which obviates the griping and facilitates catharsis; yet it is not a desirable compound. An old-time Allopathic prescription was "calomel and jalap."

The Physiomedical Dispensatory, 1869, was written by William Cook, M.D.
It was scanned by Paul Bergner at http://medherb.com