SCIENCE AND INDUSTRY. 
of these species, and a recent examination of Western Australian Y. 
preissii has-resulted in a mew species X. reflexa, which produces 
blackish gums, being proposed. In many of the chemical investigations 
already made, the value of the results obtained must be partly dis- 
counted, owing to the uncertainty of the origin of the resin. In many 
cases it has been stated as “Grass Tree resin, red or yellow variety.” 
Most of the resin examined by various German chemists many years 
- ago was apparently New South Wales red or yellow resin. We can 
probably correctly give the species for the yellow as Y. hastilis, but the 
red is doubtful. - : 
The resin is known by yarious popular names according to the 
locality. The old name is Acaroid gum (acer = bitter). Other com- 
mon names are Yacca gum, and Blackboy gum, in Western Australia. 
The resin of many species is without odour, while others have an 
agreeable smell, mostly due to the aromatic acids (e.g., benzoic). They. 
are soluble in ether, alcohol, and caustic potash. The Imperial Insti- 
tute has given the following particulars from typical samples of red. 
(R.) and yellow (Y.) resin, but no specific names are given :— 
Moisture—Y., 3 per cent.; R., 3.5 per cent, 
Ash—Y., 1.3 per cent.; 'R., .8 per cent. 
Matter insoluble in ether—Y., 23 per cent; R., 16 per cent. 
Matter (chiefly woody) insoluble in aleohol—Y., 14 per cent-; 
R., 4 per cent. . F 
Melting point—Y., 97 degrees C.; R., 110 degreés C. 
The value of the resin locally is about £5 to £6 a ton, though during 
the war prices advanced very much. 
‘The stem, or caudex, consists of a central core of fibrous, somewhat 
spongy tissue, often hard enough to be called wood. It is surrounded 
by a thick coating or “husk” formed by the persistent bases of old 
leaves, lying very ‘closely packed together, and more or less cemented 
by resin into a hard coherent mass. The bases of the individual leaves 
vary much in shape, and are an important character in identifica- 
tion. They commonly. form flattened, thickish flakes composed of a 
light fibrous skeleton and skin, serving as a support and container of 
resin, which forms the main mass of the flake. Exudations and veins 
of resin often occur in the stem. The name is derived from this 
fact—* Xanthos” yellow and “rheo” I flow = the yellow exudation, 
from the first-discovered or yellow resin variety of Botany Bay. When 
the tree dies, the core decays rapidly, leaving the husk as a thick 
cylindrical tube. In X. preissii, the internal and external diameters 
vary from 2 to 6 and 6 to 12 inches respectively. When the outer 
coating or husk is broken up and beaten, the brittle resin is readily 
reduced to a powder, and is separated from the fibrous parts by sieving 
and winnowing.. With this process there is necessarily much loss of 
material, and other methods, some of which are patented, have been 
introduced to reduce the lossy to obtain a purer resin.free from fibrous 
and mineral matter, and to retain the tree in a living condition. The 
commonest method of collecting the gum is probably -by using a 
“jigger.’. This consists of a wooden framework supporting, by. hessian 
generally, a pair of sieves. The top one, with its bagging, forms a hopper 
in which the broken-up material is collected, and sieved through a 4-in. . 
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