GUMMI ACACI.E. 233 



South Canara. The natives extract the oleo-resin in exactly the same 

 method as that followed by the ahorigines of Bi-azil in the case of 

 copaiba, — that is to say, they make a deep notch reaching to the heart 

 of the trunk, from which after a time it flows out. 



This oleo-resin, which has the smell and taste of copaiba, but a much 

 darker colour, was first examined by one of us in 18G5, having been 

 sent from the India Museum as a sample of Wood Oil; it was sub- 

 quently forwarded to us in more ample quantity by Dr, Bidie of 

 Madras. It is a thick, viscid fluid, which, owing to its intense tint, 

 looks black when seen in bulk by reflected light ; yet it is perfectly 

 transparent. Viewed in a thin layer by transmitted light, it is light 

 yellowish-green, in a thick layer vmovus-red, — hence is dichromic. It 

 is not fluorescent, nor is it gelatinized or rendered turbid by being 

 heated to 130" G, thus differinq- from Wood Oil' Broughton ' obtained 



by prolonged distillation with water an essential oil to the extent of 

 25 per cent, from an old specimen, and of more than 40 per cent, from 

 one recently collected. The oil was found to have the same composi- 

 tion as that of copaiba, to boil at 225° C, and to rotate the plane of 

 polarization to the left. The resin^ is probably of two kinds, of which 

 one at least possesses acid properties. Broughton made many 

 attempts, but without success, to obtain from the resin crystals of 

 copaivic acid. 



The balsam of HardwicMa has been used in India for gonorrhoea, 

 and witli as much success as copaiba. 



/ 



GUMMI ACACIi^. 



Gummi Arahicum; Gum Arabic; F. Gumme^ Arahiqiiej G. 

 Arahisches Gummi, Acaciev-Gummi, Kordofan Gummi. 



Botanical Origin— Among the ijlants abounding in mucilage, 

 numerous Aeacire of various countries are in the first line. The species 

 particularly known for affording the largest quantities of the finest gum 

 arable is Acacia Senegal^ Wiildenow (syn. Mimosa Senegal L., A. 

 *' ^I'ek Guillemin et Perrottet), a small tree not higher than 20 feet, 

 growing abundantly on sandy soils in Western Africa, chiefly north of 

 the river Senegal, where it constitutes extensive forests. It is called 

 tO' the negroes Verch. The same tree is likewise found in Southern 

 JNubia, Kordofan, and in the region of the Atbara in Eastern Africa, 

 '" " e it is known as Hashah. It has a greyish bark, the inner layers 



\V. *, '^^/ ''<^ further distinmiishcd from Oko-resin of Ilardwicha^^o percept- 



b th ?ii ^^ ^^^^ ^ ^"'"^ copaiba, if tested ible alteratiou ; the mixture pale greenish 



a f,,i Vi^lowiiig simple maimer:— Put into yellow. . . 



oil 1 *^ '^""^l'^ «^ bisulphide of carbon and By this teat the presence m copaiba of 



^e drop of the oleo-rcsm, and shake thcni one-eighth of \U volume of AN ood Oil may 



i,ctiier. Then add one drop of a mixture be easily shown, 



^u,;^*)^' parts of strong sulphuric and ^j-eddome, . a^ 



J^tric (1-42) acids. After a little agitation 'See also Hazlett, Ma<lro, Monihhj 



e a].pe,iranco of the respective mixtures Journ. of JM. Srimce, June 18^2 



"^ "1 be as follows :— ■* Figures in GuiUemin and Perrottet 



.J-VaiVia-Cfdour faint reddish brown, Flora' ^nwjamb. tent. 1830, p 246, tab. 



^\^. deposit of resin on sides of tube. 5C ; also JSentley and Trimcn, Mrd. Plants, 



h^Z- ^'{—^oloMT intense purplish-red, part 17 (1877). 

 t>econnng nolet after some minntes. 



