Page:The American Cyclopædia (1879) Volume IX.djvu/527

 JALAP 509 JALAP, a well known purgative drug, first introduced into England from Mexico in 1609. The plant grows wild near the city of Jalapa, and was known to the Mexicans as purga de Jalapa; that city being the point of export, the drug retains its name, heing known in the pharmacopoeias as jalapa, and in commerce and popularly as jalap. The drug was in use for over two centuries before the plant which fur- nishes it was known ; at one time it was sup- posed to be the root of a species of mirabilis, now common in our gardens as the four-o'clock, and this was called M. Jalapa, a name which it yet retains. The true jalap plant was first described by Nuttall in the " American Jour- nal of Medical Sciences" for February, 1830 ; he determined it to belong to the convolvulus family, and gave it the name of ipomcea Jalapa. As botanists have taken different views of the genera of convolmdaceoi, this plant has been alternately called ipomcea and convolvulus, but Jalap (Exogonium purga). has apparently found a resting place in exogo- nium, a genus closely related to both of these, and is the E. purga of Bentham. The habit of the plant, with long twining stems, is much like that of some of our garden species of ipo- mcea or morning glory ; but, as will be seen from the engraving, it differs in its salver- shaped corolla and protruding stamens ; the flowers are purplish and ornamental ; the root is perennial, and, according to the age of the plant, Differs in size from that of a nut to that of an orange ; it is somewhat pear-shaped or oval, externally brownish and white within. The plant is found in the elevated portions of Mexico, especially in the vicinity of Jalapa, at an altitude of about 6,000 ft. a'bove the sea ; it is quite hardy in England and on the conti- nent of Europe, and might without doubt be cultivated in the southern portions of the Uni- ted States ; but as medicinal plants are affect- ed in a marked degree by locality, experiment only could decide if the drug would be equally valuable with that grown in its native habitat. The dried root is the drug of commerce, and it undergoes no other preparation than digging and drying ; the smaller roots are dried entire ; the largest are divided longitudinally or trans- versely, sometimes cut in slices, while those of intermediate size are gashed with vertical or crosswire incisions, evidently for the purpose of accelerating the drying. The dried roots are hard and heavy, and, if of good quality, show when broken an undulated resinous frac- ture, with concentric circles of yellowish gray and dark brown portions. A whitish, mealy fracture may indicate that the root was collect- ed at an improper season, or that a spurious root has been substituted. Jalap has a heavy, rather sweetish odor, and an acrid disagreeable taste ; it forms a yellowish gray powder, which is irritating when inhaled and produces sneez- ing and coughing. The roots are often worm- eaten, but as their activity depends upon a res- in which the worms leave untouched, their value for making extract is not impaired, though if such roots were used for powdering the activity of the drug might be unduly in- creased. Jalap when treated with alcohol yields about 17 per cent, of resin, which is found to consist of two distinct resins ; one of these, to which the name of jalapine has been given, is hard and insoluble in ether; the oth- er, jalapic acid, is soluble in ether, is soft, and has the peculiar odor of jalap. Besides these resins, the drug contains sugar, a brown ex- tractive soluble in water, gum, starch, and other inert matters. In the powdering of this, as of other drugs, there is an abundant oppor- tunity for adulteration, and those who purchase the ordinary powdered jalap of commerce get a large proportion of sawdust, old ship bread, and the like ; and what is known as " over- grown jalap" or "male jalap," the root of ipomcea Orizabensit, a very feebly active purge, is often sold for grinding. Hassall found that nearly half the samples sold in London were thus adulterated. The extract of jalap is pre- pared by first exhausting the root with alco- hol, and then with water; after distilling off the alcohol from the tincture, and evaporating the watery infusion, the two are mixed and evaporated to form an extract ; this has all the medicinal properties of the root, and is em- ployed in half the dose. The resin of jalap is obtained by exhausting the root with alcohol by percolation, distilling off the greater part of the alcohol, and dropping the concentrated tincture thus obtained into water, to precipi- tate the resin, which is afterward dried and powdered. This preparation is very active, and its dose is one fifth or less of that of the powdered drug. From its action as a hydro- gogue the drug is especially adapted to the treatment of dropsy, and is commonly com- bined, when thus exhibited, with bitartrate of potassa. In the form of a powder and mixed with calomel, it has been a popular prescrip- tion in the United States in bilious fever and