Besides Mexican or Vera Cruz jalap, a drug called Tampico jalap has been imported for some years in considerable quantity. It has a much more shrivelled appearance and paler colour than ordinary jalap, and lacks the small transverse scars present in the true drug. This kind of jalap, the Purga de Sierra Gorda of the Mexicans, was traced by Hanbury to Ipomaea simulans. It grows in Mexico along the mountain range of the Sierra Gorda in the neighbourhood of San Luis de la Paz, from which district it is carried down to Tampico, whence it is exported. A third variety of jalap known as woody jalap, male jalap, or Orizaba root, or by the Mexicans as Purgo macho, is derived from Ipomaea orizabensis, a plant of Orizaba. The root occurs in fibrous pieces, which are usually rectangular blocks of irregular shape, 2 in. or more in diameter, and are evidently portions of a large root. It is only occasionally met with in commerce.
The dose of jalap is from five to twenty grains, the British Pharmacopeia directing that it must contain from 9 to 11% of the resin, which is given in doses of two to five grains. One preparation of this drug is in common use, the Pulvis Jalapae Compositus, which consists of 5 parts of jalap, 9 of cream of tartar, and 1 of ginger. The dose is from 20 grains to a drachm. It is best given in the maximum dose which causes the minimum of irritation.
The chief constituents of jalap resin are two glucosides—convolvulin and jalapin—sugar, starch and gum. Convolvulin constitutes nearly 20% of the resin. It is insoluble in ether, and is more active than jalapin. It is not used separately in medicine. Jalapin is present in about the same proportions. It dissolves readily in ether, and has a soft resinous consistence. It may be given in half-grain doses. It is the active principle of the allied drug scammony. According to Mayer, the formula of convolvulin is C34H50O16, and that of jalapin C31H50O16.
Jalap is a typical hydragogue purgative, causing the excretion of more fluid than scammony, but producing less stimulation of the muscular wall of the bowel. For both reasons it is preferable to scammony. It was shown by Professor Rutherford at Edinburgh to be a powerful secretory cholagogue, an action possessed by few hydragogue purgatives. The stimulation of the liver is said to depend upon the solution of the resin by the intestinal secretion. The drug is largely employed in cases of Bright’s disease and dropsy from any cause, being especially useful when the liver shares in the general venous congestion. It is not much used in ordinary constipation.
JALAPA, Xalapa, or Halapa, a city of the state of Vera Cruz, Mexico, 70 m. by rail N.W. of the port of Vera Cruz. Pop. (1900), 20,388. It is picturesquely situated on the slopes of the sierra which separates the central plateau from the tierra caliente of the Gulf Coast, at an elevation of 4300 ft., and with the Cofre de Perote behind it rising to a height of 13,419 ft. Its climate is cool and healthy and the town is frequented in the hot season by the wealthier residents of Vera Cruz. The city is well built, in the old Spanish style. Among its public buildings are a fine old church, a Franciscan convent founded by Cortez in 1556, and three hospitals, one of which, that of San Juan de Dios, dates from colonial times. The neighbouring valleys and slopes are fertile, and in the forests of this region is found the plant (jalap), which takes its name from the place. Jalapa was for a time the capital of the state, but its political and commercial importance has declined since the opening of the railway between Vera Cruz and the city of Mexico. It manufactures pottery and leather.
JALAUN, a town and district of British India, in the Allahabad division of the United Provinces. Pop. of town (1901), 8573. Formerly it was the residence of a Mahratta governor, but never the headquarters of the district, which are at Orai.
The District of Jalaun has an area of 1477 sq. m. It lies entirely within the level plain of Bundelkhand, north of the hill country, and is almost surrounded by the Jumna and its tributaries the Betwa and Pahuj. The central region thus enclosed is a dead level of cultivated land, almost destitute of trees, and sparsely dotted with villages. The southern portion presents almost one unbroken sheet of cultivation. The boundary rivers form the only interesting feature in Jalaun. The river Non flows through the centre of the district, which it drains by innumerable small ravines instead of watering. Jalaun has suffered much from the noxious kans grass, owing to the spread of which many villages have been abandoned and their lands thrown out of cultivation. Pop. (1901), 399,726, showing an increase of 1%. The two largest towns are Kunch (15,888), and Kalpi (10,139). The district is traversed by the line of the Indian Midland railway from Jhansi to Cawnpore. A small part of it is watered by the Betwa canal. Grain, oil-seeds, cotton and ghi are exported.
In early times Jalaun seems to have been the home of two Rajput clans, the Chandels in the east and the Kachwahas in the west. The town of Kalpi on the Jumna was conquered for the princes of Ghor as early as 1196. Early in the 14th century the Bundelas occupied the greater part of Jalaun, and even succeeded in holding the fortified post of Kalpi. That important possession was soon recovered by the Mussulmans, and passed under the sway of the Mogul emperors. Akbar’s governors at Kalpi maintained a nominal authority over the surrounding district; and the Bundela chiefs were in a state of chronic revolt, which culminated in the war of independence under Chhatar Sal. On the outbreak of his rebellion in 1671 he occupied a large province to the south of the Jumna. Setting out from this basis, and assisted by the Mahrattas, he reduced the whole of Bundelkhand. On his death he bequeathed one-third of his dominions to his Mahratta allies, who before long succeeded in annexing the whole of Bundelkhand. Under Mahratta rule the country was a prey to constant anarchy and intestine strife. To this period must be traced the origin of the poverty and desolation which are still conspicuous throughout the district. In 1806 Kalpi was made over to the British, and in 1840, on the death of Nana Gobind Ras, his possessions lapsed to them also. Various interchanges of territory took place, and in 1856 the present boundaries were substantially settled. Jalaun had a bad reputation during the Mutiny. When the news of the rising at Cawnpore reached Kalpi, the men of the 53rd native infantry deserted their officers, and in June the Jhansi mutineers reached the district, and began their murder of Europeans. The inhabitants everywhere revelled in the licence of plunder and murder which the Mutiny had spread through all Bundelkhand, and it was not till September 1858 that the rebels were finally defeated.