Incense to the value of nearly one million and a quarter francs was exported from Alexandria in 1837.

Calambak or eagle wood, the true lignum aloes so highly esteemed in the East as a perfume or incense, is said to be produced by the Aloexylum agallochum, Lour.  This remarkable wood contains a large quantity of an odoriferous oleo-resin; when heated it undergoes a sort of imperfect fusion, and exhales a fragrant and very agreeable odor.  Its price in Sumatra is about L30 per cwt.  Inferior specimens are obtained at Malacca.  Eagle wood is also obtained from several other trees.  The true eagle wood is however very scarce.

SECTION IV.

DYES AND COLORING STUFFS, AND TANNING SUBSTANCES.

Of the several classes of materials collected at the Industrial Exhibition in Hyde Park, in 1851, few possessed so much importance in the eyes of the textile and leather manufacturer and chemist as the different products used in the arts and manufactures for coloring and tanning purposes.  These were in a great measure lost sight of by the public at large, being scattered about in small quantities in a great number of directions; and, from the minute samples shown, were in many instances overlooked altogether.  Besides furnishing some novel and general statistical facts, which may prove interesting, I propose also in this section to draw attention more prominently to some of these products, which are at present little known or appreciated.

Coloring substances for staining and dyeing are obtained indifferently from the animal, mineral, and vegetable kingdoms, but it is of the last alone that I shall have to speak.  The importance of a more careful consideration of this subject will be admitted, if we consider how much the prosperity and extent of our cotton, silk, woollen, and leather manufactures depends on a liberal and cheap supply of dyes and tannin, to give beauty and color to the fabrics, and substance and utility to the skins.  Even oil colors, for painters’ purposes, which do not come within the scope of my remarks, form an item in our yearly exports of the value of L250,000, and when we calculate the large amount of cotton, silk and wool worked up, most of which requires various coloring agents, gums, starches, and mordants;—­that nearly 30,000 tons of hides are annually imported, exclusive of those obtained from our now slaughter-houses, besides goat, seal, and other skins—­and that the exports of our various manufactures of cotton, linen, silk, wool and leather in 1852, setting aside our home consumption, amounted to nearly fifty millions sterling, we shall be able to form a better estimate of the importance of the various subjects we are about to notice.

Great Britain does not pay less than L600,000 annually for the dried carcasses of the tiny cochineal insect, while the produce of another small insect, that which produces the lac dye, is scarcely less valuable.  Then there are the gall nuts used for dyeing and making black ink.  Upwards of L3,000,000 is paid for barks of various kinds for tanners’ purposes, about one million for other tanning substances and heavy dye woods, besides about L200,000 for various extracts of tannin, such as Gambier, Cutch, Divi-divi, and Kino.  The aggregate value of the dye stuffs and gum it is difficult to estimate.