228 AUSTRALIAN NATIVE PLANTS. 
do the drying oils, but it may be made to combine with these 
solvents by previous fusion.”’ 
A sample in the Technological Museum is of a dark-amber 
colour, and externally possesses the dulled appearance of lumps 
of amber. It is the darkest resin of the genus examined by me. 
Northern New South Wales and Queensland. 
12. Grevillea robusta, 4. Cunn., (Syn. G. umbratica, A. Cunn.); 
N.O., Proteacez, B.FI., v., 459. 
“‘ Silky Oak.” (For aboriginal names, see ‘‘ Timbers.’’) 
This tree is frequently planted for ornamental and shade pur- 
poses in the colonies, but to a far greater extent in Ceylon, India, 
Algeria, &c. It exudes a gum resin, which I have never seen 
except in minute quantity in Australia, but it appears to be more 
abundant in India and Algeria. Cooke (Gums and Resins of 
India) thus describes it: . . . “of a vinous-red colour 
and but little soluble; it is said to have been obtained from this 
tree, which is cultivated to a limited extent in Mysore. It has a 
bright, shining, resinoid fracture, which it retains. It is much 
mixed with pieces of friable bark, to which it adheres.”’ 
In some notes (1881) on the Shevaroy Hills, India, by Deputy 
Surgeon-General Shortt, the following passage occurs :—‘‘ Of 
the plants intoduced in these hills, I have to notice a peculiarity 
as regards Grevillea robusta; one tree, which is now eleven 
years old, has for the last two years, during the rains, produced 
spontaneously each year about ten ounces of a translucent gum, 
which has no smell or particular taste, is of a pale-yellow colour, 
and mixes readily with water, when it forms a whitish-brown 
coloured mucilage, and, as a paste, answers all the purposes of the 
so-called gum arabic for adhesive purposes.” 
This gum-resin has been examined by Fleury (see Fourn. 
Pharm. [5], ix., 479-80), an abstract of whose paper is given in 
Fourn. Chem. Soc., xlviii., 238. He describes it as yellowish- 
red, slightly translucent, slightly friable, and similar in appearance 
to cherry-gum. In water it swells a little, and slowly produces a 
very persistent white emulsion, which passes through all filters. It 
contains no starch, but gives 3 per cent. of ash. The emulsion 
