The soap-worts to which the genus Sapindus belongs are tropical plants.  The fruit of many species of Sapindus is used as a substitute for soap, as Sapindus acuminata, Laurifolius emarginatus and detergens, all East Indian plants.

SECTION VI.

PLANTS YIELDING DRUGS, INCLUDING NARCOTICS AND OTHER COMMON MEDICINAL SUBSTANCES.

The chief plants furnishing the drugs of commerce, and which enter largely into tropical agriculture, are the narcotic plants, especially tobacco, the poppy for opium, and the betel nut and leaf; as masticatories—­but there are very many others to which the attention of the cultivator may profitably be directed.  I have already trenched so largely upon my space, that I cannot do that justice to the plants coming under this section I could have wished.  There are very many, however, of which I must make incidental mention.  Some few medicinal plants have been already alluded to in former sections, particularly in that on dye-stuffs, &c.

THE COCA PLANT grows about four or five feet high, with pale bright green leaves, somewhat resembling in shape those of the orange tree.  The leaves are picked from the trees three or four times a year, and carefully dried in the shade; they are then packed in small baskets.  The greatest quantity is grown about 30 leagues from Cicacica, among the Yunnos on the frontiers of the Yunghos.  Some is also cultivated near to Huacaibamba.

The natives in several parts of Peru chew these leaves as Europeans do tobacco, particularly in the mining districts, when at work in the mines or travelling; and such is the sustenance that they derive from them, that they frequently take no food for four or five days.  I have often (observes Mr. Stevenson) been assured by them, that whilst they have a good supply of coca they feel neither hunger, thirst, nor fatigue, and that without impairing their health they can remain eight to ten days and nights without sleep.  The leaves are almost insipid, but when a small quantity of lime is mixed with them, they have a very agreeable sweet taste.  The natives generally carry with them a leather pouch containing coca, and a small calabash holding lime or the ashes of the molle to mix with them.

Cocculus indicus, or Indian berries.—­This is the commercial name for the berries or fruit of the Menispermum Cocculus of Linnaeus, M. heteroclitum of Roxburgh, Animerta paniculata of Colebrooke, A.  Cocculus of Wright and Arnot, and Cocculus suberosus of Decandolle.  It is a strong climbing shrub or tree, native of Malabar, Ceylon, and the Eastern Islands.  The seeds or drupes contain a bitter poisonous acid, and are used for the purpose of stupefying fish, and, in the form of a black extract, for fraudulently increasing the intoxicating power of malt liquors; one pound of the berries, it is said, will go as far in brewing as a sack of malt.  The berry is kidney-shaped, with a white kernel.  Whilst the imports in 1846 were but 246 bags, in 1850 they had increased to 2,359 bags of about 1 cwt. each.  The price is 19s. to 24s. the cwt.