. Spec. Plant. Willd. iv. 1085. Cl. 23. Ord. 1. Polygamia, Monoecia. Nat. ord. Leguminosse. G. 1902. Hermaph. Calyx five-toothed. Corolla five-cleft, or formed of five petals. Stamens 4-100. Pistil. 1. Legume bivalve.

Male Cal. five-toothed. Cor. five-cleft, or formed of five petals. Stam. 4-100. **** Leaves bipinnate, stipular thorns or prickles, elongated spikes. Species 73. Acacia Catechu.1 Catechu. Med. Pot. 3d edit. t. 157. ***** Leaves bipinnate, stipular thorns, globular spikes. Species 87. Acacia vera. Acacia or Egyptian thorn, Med. Pot.

3d edit. t. 158. Vesl. Aegypt. t. 8. bona.

1. Acacia Catechu.

Officinal. Catechu, Lond. Acaciae Catechu Extractum, Edin. Acacia Catechu; Extractum ex Ligno, Dub.

Extract of Catechu.

Syn. Cachou(.F.), Katechu; Katchu (G.), Cato o Catecu (I.), Catecu (S), Cato (Portug.), Cutt (Hind.).

This tree grows plentifully in the mountains of Kanhana in Hindostan; and flowers in June. It seldom exceeds twelve feet in height, and one foot in the diameter of its stem, which is covered with a thick, rough, brown bark, and towards the summit is divided into many close branches. The leaves are placed alternately on the younger branches; and are composed of fifteen or thirty pairs of pinna?, nearly two inches long, each having about forty pairs of linear leaflets, beset with short hairs; with a small gland on the common petiole between the bases of each pair of the pinnae. At the base of each leaf are two short recurved, compressed spines. The flowers are hermaphrodite and male; axillary, and on close spikes four or five inches long; the calyx is tubular, hairy, dividing into five oval-pointed segments; the corolla of one piece, whitish, twice the length of the calyx, and of the same form. The filaments are numerous, double the length of the corolla, crowded with roundish anthers, and adhering at the base of the gem, which is oval, supporting a slender style the length of the filaments, and terminated by a simple stigma.

The fruit is a lanceolate, compressed, smooth, brown pod, with an undulated, thin margin; and contains six or eight roundish, flattened seeds, which emit a disagreeable odour when chewed.

The inner wood of this tree is of a brown colour; and from it, according to Mr. Ker's statement2, the catechu is prepared. "After felling the trees, the manufacturer carefully cuts off all the exterior white part of the wood. The interior coloured part is cut into chips, with which he fills a narrow-mouthed unglazed earthen pot, pouring water upon them until he sees it among the uppermost chips: and when this is half evaporated by boiling, the decoction, without straining, is poured into a flat earthen pot, boiled to one third part, and then set in a place to cool for one day. The decoction is afterwards evaporated by the heat of the sun, stirring it several times in the day; and when it is reduced to a considerable thickness, it is spread upon a mat or cloth, which has previously been covered with the ashes of cow-dung. The mass is lastly divided, by a string, into square or quadrangular pieces, which are completely dried by turning them in the sun, until they are fit for sale." Before this account was published, Catechu was generally supposed to be extracted from the Areca nut; but although there are two other species of Catechu, the one named Cuttacamboo, the other Cashcutti, yet neither are extracted from that nut.

All three are used by the Indian practitioners.

Theophrasti. Dioscorides also mentions this species of Acacia. The name in Bahar is Coira or Keira. 2 Med. Obs. and Enquir. vol. v. p. 151.

This extract, when first introduced as a medicine into Europe, was named Terra Japonica, from the supposition that it came from Japan, and was an earth. It is named cutt by the natives of Hindostan, cutch by the English, and by different authors khaath, cate, cachou, cachore1, and catechu.2 There are two varieties of the true Catechu; one brought from Bengal, the other from Bombay. It is imported into Britain in bags, and sometimes in boxes or chests, containing from 3 to 4 cwt. each; and occasionally in small squares, in boxes. Pale and dark-coloured Catechu are mixed in the same package.

Qualities.-Pale Catechu is generally in small round or square cakes of a pale reddish brown colour, light and friable, with a lamellated texture, and rough fracture; has a bitterish and astringent taste, leaving a degree of sweetness on the palate; is inodorous, and has a specific gravity between 1.28 and 1.39. The dark, which is in round masses, has a deep chocolate-colour internally, with the hue of rusty iron on the outside; the texture is uniform, and the fracture resinous, marbled, and shining. It is heavier than the pale, the specific gravity being 1.45, and has a more austere and bitter taste; but in other respects it agrees with the other kind. Both are often much adulterated with sand and other impurities. Water at 60° dissolves 3 parts in 4 of pale Catechu; the alkalies deepen the colour of the solution, until on standing it becomes of a deep mahogany hue. According to the analysis of Sir H. Davy, there appears to be very little difference between the two varieties. Both are almost entirely soluble in the mouth, 100 grains, macerated in 18 fluid ounces of water, at 52°, left 7 1/4 grains only undissolved, and these were chiefly lime, aluminous earth, and sand. The solutions are inodorous, and slightly redden tincture of litmus.

Strong sulphuric and muriatic acids throw down fawn-coloured precipitates in them: persulphate of iron, acetate of lead, muriate of tin, and gelatine also throw down precipitates 1 demonstrating the presence of tannic acid; what remains after the action of alcohol is a coloured mucilage; and when fine powder of Catechu is washed with small quantities of water until all the tannin and mucilage are dissolved, a pale red extractive matter, inodorous, very slightly astringent, sweetish, and soluble in water and in alcohol, and giving a green colour to persulphate of iron, is obtained as a residue. The proportions of these constituents, according to Davy's experiments, were as follows: 200 grains of Bombay Catechu afforded 109 of tannin, 68 of extractive matter, 13 of mucilage, and 10 of earths and other impurities. The same quantity of Bengal Catechu gave 97 of tannin, 73 of extract, 16 of mucilage, and 14 of impurities.2

1 Bolduc, Mem. Acad. 1709, p. 293.

2 This name is said to be compounded of two Oriental words, cate, which signifies a tree, and chn, juice. Ker, 1. c.