It is of two sorts, viz.:—
1. Flag or cake arnotto, which is by far the most important article in a commercial point of view, is furnished almost wholly by Cayenne. It is imported in square cakes, weighing two or three pounds each, wrapped in banana leaves, packed in casks.
2. Roll arnotto is principally brought from Brazil. The rolls are small, not exceeding two or three ounces in weight. It is hard, dry, and compact, brownish on the outside, and of a beautiful red color within.
The dye is usually prepared by macerating the pods in boiling water for a week or longer. When they begin to ferment, the seeds ought to be strongly stirred and bruised with wooden pestles to promote the separation of the red skins. This process is repeated several times, till the seeds are left white. The liquor passed through close cane sieves, pretty thick, of a deep red color, and a very bad smell, is received into coppers. In boiling, it throws up its coloring matter to the surface in the form of scum, which is taken off, saved in large pans, and afterwards boiled down to a due consistence, and then made up, when soft, into balls or cakes of two or three pounds weight.
The following description of the manufacture is from Dr. Ure:—
"The pods of the tree being gathered, their seeds are taken out and bruised; they are then transferred to a vat, which is called the steeper, where they are mixed with as much water as covers them. Here the substance is left for several weeks or even months; it is now squeezed through sieves placed above the steeper, that the water containing the coloring matter in suspension may return into the vat. The residuum is preserved under the leaves of the pine-apple shrub, till it becomes hot by fermentation. It is again subjected to the same operation, and this treatment is continued till no more color remains.
"The substance thus extracted is passed through sieves, in order to separate the remainder of the seeds, and the color is allowed to subside. The precipitate is boiled in coppers till it be reduced to a consistent paste; it is then suffered to cool, and dried in the shade. Instead of this long and painful labor, which occasions diseases by the putrefaction induced and which affords a spoiled product, Leblond proposes simply to wash the seeds of arnotto till they be entirely deprived of their color, which lies wholly on their surface; to precipitate the color by means of vinegar or lemon juice, and to boil it up in the ordinary manner, or to drain it in bags as is practised with indigo.
"The experiments which Vauquelin made on the seeds of arnotto imported by Leblond, confirmed the efficacy of the process which he proposed; and the dyers ascertained that the arnotto obtained in this manner was worth at least four times more than that of commerce; that, moreover, it was more easily employed; that it required less solvents; that it gave less trouble in the copper, and furnished a purer color."—("Dict. of Arts.")
Our imports of arnotto for home consumption are from 200,000 to 300,000 lbs. per annum. The plant is grown in Dacca and other parts of India, and the eastern Archipelago. At the Hawaiian Islands, Tongataboo, Rio Janeiro, Peru and Zanzibar, the arnotto is an indigenous shrub which rises to the height of seven or eight feet, producing oblong heavy pods, somewhat resembling those of a chesnut. Within these there are generally thirty or forty irregularly-formed seeds, which are enveloped in a pulp of a bright red color, and a fragrant smell.