_Guatemala floro_.—Bright blue, paste uniform, soft and light. This variety, in Bancroft’s time, was the most esteemed of all indigoes.
_Guatemala sobresaliente_.—Less light, the paste firmer and the blue less beautiful.
_Guatemala corte, or copper-colored_.—Paste less firm and heavier, coppery red.
_Caraccas_.—These resemble very much the Guatemala varieties. The qualities are designated by analogous names, but they are, in general, less esteemed than the preceding.
_Mexican_.—They hold an intermediary rank between the Caraccas and Mexican.
_Brazil_.—These indigoes are in small rectangular parallele-piped masses, or in irregular lumps of a greenish gray color externally, and having a smooth fracture, a firm consistency, and a copper-colored tint of greater or less brilliancy.
_The indigoes of Africa and Egypt_.—These have only been manufactured within the last twenty years; they are in flat squares. The paste is fine and quite light, and the color pure blue or bordering on violet. The varieties are distinguished as fine blue and good violet and red.
_Indigoes of the Isle of France and Senegal_. Rare in commerce, but of good quality.
The indigoes of the inferior qualities, characterized by a salt-like color, bordering more or less upon green; by a coarse, uneven, and very dense paste; by not adhering to the tongue, and by not showing a coppery color when scratched,—can never be employed to advantage, notwithstanding their low price. The purchaser of these qualities must be guided solely by the results of analysis; for an article is found in commerce whose richness in indigotine does not exceed twelve to fourteen per cent. The presence of so high a proportion of foreign matter prevents the chemical change which the indigo ought to undergo in the dyeing vat; and this foreign matter, added to the deposits of the dyeing vats, causes great loss of the coloring matter. These indigoes should be used as little as possible, especially in the cold vats used for dyeing cotton and linen. The middle varieties of the Bengal and Guatemala indigoes, and, above all, the red varieties, produce in the cold vats the most advantageous results. The lower qualities above spoken of present less inconvenience in the hot vats used for dyeing wool; and it is for this purpose that they are generally used. In considering the previous observations, the wool manufacturer may arrive at this conclusion: that while he can, with less loss than the maker of cotton fabrics, make use of the lowest qualities of indigo, he will obtain _the best results from the middle qualities of the reddish Bengal indigoes_.