10 



ABUT A A C A C I A. 



human system to circumstances, they do not come 

 within the legitimate province of Natural History. 



ABUTA (Aublet). A genus of evergreen climbing 1 

 plants. Linnaean class and order, Dicecia Polyandria ; 

 Natural order, Mcnispermncece, Of this genus there 

 are only two species described, viz. A, rufescens, rufes- 

 cent ; and A. candlcans; both natives of Cayenne. 



ACACIA. An extensive genus of exotic trees 

 and shrubs belonging to the Linnsean class and order 

 Polygamia Moncecia ; and to the natural order Legu- 

 minoste, division Mimosece, of Jussieu. The name is 

 derived from the Greek word u.x.a.Z,a, to sharpen, in 

 consequence of many of the species being thorny. 

 Generic character : flowers, polygamous ; calyx, four 

 or five toothed ; the petals of the corolla four or five, 

 at one time free, at another coalescing ; stamens vary- 

 ing from ten to 200; pods not jointed, juiceless, and 

 two-valved. 



Branch of the Acacia. 



The species included under this genus are very 

 numerous, amounting to about 300. They are shrubs 

 and trees, varying in habit and foliage ; and while by 

 their beauty and elegance they contribute not a little 

 to adorn the countries in which they grow, they 

 are found to be of essential service in the arts and 

 manufactures by supplying them with a hard and 

 durable wood, which is deservedly much valued. 

 They are found in the tropical regions of Asia, Africa, 

 and America, and also abundantly in New Holland, 

 Van Diemen's Land, and New South Wai eg. They 

 all bear pods like the pea family, but in their blossoms 

 they have a considerable resemblance to the willow 

 tribe. By their airy foliage and golden flowers 



they throw a charm even over the sterile deserts of 

 Africa : 



" Our rocks are rough; but smiling 1 there 

 Th' acacia waves her yellow hair ; 

 Lonely and sweet, nor l:>v'd the less 

 For ftow'ring in the wilderness." 



The leaves are, as we have already stated, in the 

 grealer number of the species, pinnate, that is, having 

 a central stalk and numerous small leaflets on either 

 side of it, as represented in the engraving; in others, 

 however, the leaf-stalks become dilated vertically into 

 hard, leathery expansions, denominated Pliyllodla, 

 which seem to serve all the purposes of leaves, and 

 which in their young state generally bear leaflets. 

 From this difference in the foliage, the species have 

 been divided into those having pinnate leaves, and 

 those provided with pliyllodia. The latter are of 

 frequent occurrence in New Holland and the other 

 parts of Australia, and may be said, in some degree, 

 to characterise the vegetation of those countries. 



We shall notice a few of the important species. 

 The Acacia Arabics, vcra, ScncgaJcnsis, and Nihticct, 

 &c., are interesting in a commercial point of view, as 

 yielding the substance called Gum-Arabic. This 

 exudes either spontaneously or from incisions made 

 into the bark, and subsequently hardens by exposure 

 to the air. When pure it is transparent and colour- 

 less, has neither taste nor smell, and is perfectly 

 soluble in water, forming what is called mucilage. 

 Gum Arabic derives its name from having been 

 originally brought from Arabia ; subsequently, how- 

 ever, Africa, more especially Senegal, has furnished 

 a considerable quantity. From this circumstance the 

 name of Gum Senegal has been given to some varie- 

 ties. The Gum Arabic tree is also found in the East 

 Indies. The gum is collected in the months of 

 December and January, and sold in large quantities 

 to French and English merchants. It is capable of 

 being used as an article of food, and is very nutrition?. 

 During the time of the gum harvest the collectors 

 subsist upon it entirely, and six ounces are said to be 

 the usual allowance for an adult, in the course of 

 twenty-four hours. Gum is used extensively in medi- 

 cine, as a bland mucilaginous substance, for the pur- 

 pose of allaying various irritations. It is made into 

 the form of lozenges and jujubes with several other 

 substances. It is useful in the arts, being employed in 

 calico-printing to give consistency to colours, and to 

 prevent their spreading. For similar reasons it enters 

 into the composition of writing ink, blacking, &c. 

 Botanists employ it to fix the dried specimens of 

 plants upon paper, and it is used in the formation of 

 numerous fancy and ornamental articles, such as seals, 

 rice boxes, &c. The bark of the Gum Arabic tree is 

 employed in India as a tonic for strengthening the 

 stomach, and a decoction of its pods serves for the 

 purpose of washing. 



Another species of Acacia, the Acacia Catechu, or 

 Khair tree, a native of the mountainous parts of 

 Hindostan, deserves notice chiefly on account of its 

 yielding a substance which is used in medicine. This 

 substance, which was formerly erroneously denomi- 

 nated Japan Earth, but now receives the name of 

 Catechu, is an extract from the internal part of the 

 wood of this tree prepared in Bengal, and other parts 

 of India, by decoction and evaporation. The extract 

 is also prepared from the pods of the tree, as well as 

 from other plants, such as the Nauclea Gambic and 

 Areca Catechu. It has a reddish brown colour, and 



