previous
next

Exudation

— The gum of this species is only partially soluble. It is rare and is not likely to be of commercial importance. Following is a notenote on a specimen:—

This sample is in small amber-coloured pieces and is very much admixed with woody matter. It is fairly transparent, and breaks with a bright fracture. It is only partly soluble in water, the soluble portion being arabin. it forms a fairly adhesive liquid. It gives no precipitate with ferric chloride, nor does it form a jelly, and only slightly darkens when heated with dilute soda. The unsoluble portion is soluble in dilute alkalis, and is precipitated as arabin on acidifying with acetic acid and adding alcohol.
previous
next