India rubber is obtained mostly from the Seringueros of the Amazon, who sell it for about 12 cents a pound to the merchants of Para, but its value on reaching England or the United States is over 50 cents a pound. The best rubber forests in Brazil will ultimately be exhausted, owing to the reckless mode followed by the Seringueros or tappers. The ordinary product of a tapper's work is from 10 to 16 pounds daily. There are 120 india rubber manufacturers in the United States, employing 15,000 operatives, who produce 280,000 tons of goods, valued at $260,000 000, per annum.

Amber is a substance analogous to the vegetable resins, usually of a pale-yellow color. It occurs in round, irregular lumps, grains or drops, slightly brittle and emits a pleasant odor when rubbed. It melts at 536° F. Amber becomes negatively electric by friction, and possesses this property in a high degree - which, indeed, was first observed in it, and the term electricity is derived from elektron, the Greek name of amber. The specific gravity of amber is 1.065 to 1.070. Amber was anciently regarded as a charm against witchcraft. It is employed extensively in the arts, for the mouthpieces of pipes, for jewelry and other ornamental purposes.

The name alcohol (Arab. al-koh'l, originally applied to a collyrium, a very fine powder of antimony for staining the eyelids; afterwards "essence," "spirits"). Ordinary or ethyl alcohol is a limpid, colorless liquid, of a hot pungent taste, and having a slight but agreeable smell. It is the characteristic ingredient of fermented drinks, gives them their intoxicating quality, and is obtained from them by distillation. It is said to have been first obtained by this process by Abucasis, in the twelfth century. If we look at the extraordinary consumption of these liquors for various purposes, it is seen to be one of the most important substances produced by art.

The overland route to India, Australia and the East, is now understood to be that from England across France, through Mont Cenis by tunnel, to Brindisi in Italy, thence through the Levant, the Suez Canal, Red Sea and Indian Ocean. This makes the journey only about half as long as the voyage round by the Cape of Good Hope, a little over six thousand miles instead of more than twelve thousand. The saving in time is even more considerable. The time from London to Bombay is about four weeks, instead of three months by the Cape. In 1838 a monthly service was started to carry the mails across Egypt; but to Lieutenant Waghorn (1800-50) belongs the credit of first showing how the voyage from India could be still further shortened. On October 31, 1845, he arrived in London with the Bombay mail of October 1 (via Austria, Bavaria, Prussia and Belgium) The railway from Suez to Alexandria by Cairo was opened in 1858; but the great event that rendered the overland route available for passengers generally was the opening of the Suez Canal in 1869.

The variety of starch called Arrowroot is extracted from the roots of certain plants growing in tropical countries. It is a fine starchy farina, much valued as a delicacy, and as an easily digestible food for children and invalids. It is obtained from the root-stocks of different species of Maranta. The species chiefly yielding it is a native of tropical America, cultivated in the West India Islands, and growing about two feet high, with ovate-lanceolate somewhat hairy leaves, clusters of small flowers on two-flowered stalks, and globular fruit about the size of currants. The rhizomes are often more than a foot long, of the thickness of a finger, jointed, and almost white, covered with large papery scales. They are dug up when a year old, washed, carefully peeled, and reduced to a milky pulp. In Jamaica the roots are reduced by beating in deep wooden mortars; in Bermuda by means of a wheel-rasp; but modern machinery has now been introduced.

Steam navigation practically commenced in 1802, with the launch of the "Charlotte Dundas," which plied on Forth and Clyde Canal. She had one paddle-wheel near the stern. Fulton, who invented the paddle-box, established the American steamboat system with his "Clermont" (1807), which plied on the Hudson. The first steamer used in ocean navigation was Stevens' "Phoenix," which steamed from New York to Philadelphia in three days (1808.) The first passenger steamer in Great Britain was Henry Bell's "Comet," built at Port Glasgow (1812.) The first steam vessel in the British navy was also called the "Comet," built at Woolwich dockyard (1822). Regular steamboat communication across the Atlantic was established in 1838. The first screw steamer in Great Britain was the "Archimedes," built on the Thames (1839); the first screw steamer in the British navy was the "Dwarf (1843); and the first iron screw steamer was the "Fire Queen," built at Glasgow(1845). Ocean steamers are now built of steel.

A famous Indian product is Arrack, or Rack, a name often used for all sorts of distilled spirituous liquors, but chiefly applying to that procured from toddy or the fermented juice of the cocoa or other palms, as well as from rice, and the kind of brown sugar called jaggery. The palms in other tropical countries furnish a fermented beverage similar to the toddy of India, and in a few instances also it is distilled, but arrack essentially belongs to India and the adjacent countries. The cocoanut palm is a chief source of toddy or palm wine, which is obtained from trees ranging from twelve to sixteen years old, or in fact at the period when they begin to show the first indication of flowering. After the flowering shoot or spadix enveloped in its spathe is pretty well advanced, and the latter is about to open, the toddy-man climbs the tree and cuts off the top of the flower-shoot; he next ties a ligature round the stalk at the base of the spadix, and with a small cudgel he beats the flower-shoot and bruises it. This he does daily for a fortnight, and if the tree is in good condition, a considerable quantity of a saccharine juice flows from the cut apex of the flower-shoot, and is caught in a pot fixed conveniently for the purpose, and emptied every day.

It flows freely for fifteen or sixteen days, and less freely day by day for another month or more; a slice has to be removed from the top of the shoot very frequently. The juice rapidly ferments, and in four days is usually sour; previous to that it is a favorite drink known in some parts of India as callu, and to the Europeans as toddy. When turning sour, it is distilled and converted into arrack. It is largely manufactured in Goa, Batavia, Ceylon and Siam. A similar spirit is made pretty largely from the magnificent fan-leaved palm, and also from the so-called date-sugar palm. The name is also given to a spirit obtained from rice and sugar fermented with cocoanut sap. An imitation arrack may be prepared by dissolving ten grains of benzoic acid in a pint of rum.