taken ext of the watery solution by ether. It crystallises in groups 
8, Which are insoluble in water, alcohol, benzol, and acetic 
acid, 4 which dissolve easily in ether, chloroform, and acetic ether 
Tr some 
he 
19°4 
F or) eee eee 86 
Grevillea arabi Rete ora ene. f iy 
é Bitter crystals from ether.. |. |. 2. 08 
The Grerie gum resin can be used like arabic gum for all 
ordinary pu 
" TAN-RESIN GUMS. 
Asmnaent Gung’ CONTAINING A Taw Rusty on Extacitc Acrp AND 
ESIN, 
This section comprises the Eucalyptus and Angophora me 
oe ae partly: insclable in water. They form Mr, Maiden 
1 grou i 
Cera essential constituent of a sample from one species might 
ent at hence the wide discrepancy in the statements 
The percentage varies altogether. 
tan-resin gums of the Myrtacee are cutialy endemic in 
ona a 48 no plant of eee country yields an exudation similar 
The chemical com posit ie 
aris tan-resin gums all ae with each other in some essenti 
in ty they all contain = stained delicately blue by ferric salt 
wid tilute Solution. These tannins have nothing . do with kinotannie 
vs they yield - rogallol ‘by dry distillation.* 
hot That t part of the tan-resin gum which is insoluble in water does 
sepa any catechin,* as it yields pyrogallol by dry distillation, 
tunresin i ss of it gives a green reaction with ferric salt. In some 
Water j a large proportion of the part which is insoluble in 
@ alo indetihie 3 in aleohol 
“Sache lanceolata, Cav., Fl. Austr. iii. 184. Rusty Gum. 
bial. Cntains no volatile oil in the foliage. It has a ‘smooth aches 
nit et rak gum, which is liquified by rains and run in 
SiS Bi Se Nh Sk 9 9 an “ry Rn 
Rene nse ale EN aban te ko ws 
n dissolved j m water it leaves a whitish, insolvent, powdery 
: t dissolves to a great extent in hot water, but the rtp 
ooks turbid at first. A pinky-white precipitate occupies the 
nent). me of the liquid (65 per cent. soluble, 35 per cent. 
, This ta d out of 
the sin gum is “ soluble in cold water; an 
mea hee tion ae es som : tanding, a white powder is — 
ein aleohol, ether, ae asétic ether. 
Mane or anointed out fi read at Brisbane before the 
ret by the writer in a paper 
Of Science Hie Pach 1895. 
