This of course induced further inquiry, and on consulting different works I find that the Cape of Good Hope possesses more species of indigo than the whole world besides. Now I take it for granted that if Providence has placed these materials within our reach, it was evidently intended that we should, by the application of industry, appropriate them to our use. It becomes, then, a matter of necessity that indigo must thrive, this being its native soil and climate; and the experiments I have successfully made, go to support me in the opinion that the cultivation of indigo will bring an ample reward. Indeed it seems contrary to the laws of nature that it should be otherwise.
I have obtained from the 140th part of an acre the proportion of 300 lbs. of indigo per acre. That the plant will cross successfully, I have also ascertained."
Cultivation in India.—During the nine years which preceded the opening of the trade with India in 1814, the annual average produce of indigo in Bengal, for exportation, was nearly 5,600,000 lbs. But since the ports were opened, the indigo produced for exportation has increased fully a third; the exports during the sixteen years ending with 1829-30, being above 7,400,000 lbs. a year.
The consumption in the United Kingdom has averaged, during the last ten years, about 2,500,000 lbs. a year.
In 1839-40 the export of indigo from Madras amounted to 1,333,808 lbs. A small quantity is also exported from the French settlement of Pondicherry. In 1837 the export from Manila amounted to about 250,000 lbs. The export from Batavia in 1841 amounted to 913,693 lbs., and the production in 1843 was double that amount. The annual exports of indigo, from all parts of Asia and the Indian Archipelago, were taken by M'Culloch, in 1840, to be 12,440,000 lbs. The imports are about 20,000 chests of Bengal, and 8,000 from Madras annually, of which 9,000 or 10,000 are used for home consumption, and the rest re-exported.
The total crop of indigo in the Bengal Presidency has ranged, for the last twenty years, at from 100,000 to 172,000 factory maunds; the highest crop was in 1845. The factory maund of indigo in India is about 78 lbs.
In the delta of the Ganges, where the best and largest quantity of indigo is produced, the plant lasts only for a single season, being destroyed by the periodical inundation; but in the dry central and western provinces, one or two ratoon crops are obtained.
The culture of indigo is very precarious, not only in so far as respects the growth of the plant from year to year, but also as regards the quantity and quality of the drug which the same amount of plant will afford in the same season.
The fixed capital required, as I have already shown, in the manufacture of indigo, consists simply of a few vats of common masonry for steeping the plant, and precipitating the coloring matter; a boiling and drying house, and a dwelling for the planter. Thus a factory of ten pair of vats, capable of producing, at an average, 12,500 lbs. of indigo, worth on the spot £2,500, will not cost above £1,500 sterling. The buildings and machinery necessary to produce an equal value in sugar and rum, would probably cost about £4,000.
The indigo of Bengal is divided into two classes, called, in commercial language, Bengal and Oude; the first being the produce of the southern provinces of Bengal and Bahar, and the last that of the northern provinces, and of Benares. The first class is in point of quality much superior to the other. The inferiority of the Oude indigo is thought to be more the result of soil and climate, than of any difference in the skill with which the manufacture is conducted. The indigo of Madras, which is superior to that of Manila, is about equal to ordinary Bengal indigo. The produce of Java is superior to these.