i 89 
] bb. Watery solution giving only a white proainttade with 
alcohol, but not stained yellow 
1. Part of the gum, left undibechied by cold water, is 
stained golden-yellow by cold Ose “potash solution. 
mum a e, Cun 
2. Part left undissolved in cold site not stained golden 
with caustic potash. 
a. Metarabin dissolved by boiling hydrochloric acid 
is precipitated by peed in the sour state. 
Bauhinia Hookeri 
b. Metarabin dissolved by boil hydrochloric acid is 
PS dee by alcohol only on addition of alkalies. 
. Metarabin is dissolved by cold caustic potash. 
cacia Cunninghamit, 
bb. svernas is dissolved by caustic —_ only on 
ae Part of the — srenigie falls out after 
cia decurrens, 
2. Metarabin sclaaans in caustic potash keeps clear 
after cooling. Acacia ia penninerois, Sieb. 
C.—GUM RESINS AND TAN RESINS. 
(Dissolved in water but only partly.) 
dig luble in water, not stained blue by ferric salt. Dry 
tiati ka phenol and catechol. 
Gum Resins. 
1. Part, soluble in water, consists of metarabin, stained yellow sd 
KOH H (before it is dissolved by it) and not at wit 
ferric salt. (Page 50.) ittosporum undulatu 
2. Part, soluble in water, consists of a kind of abi, *gelatinising 
on addition of ferric salt. 
a. Arabin gelatinising “with ferric salt without addition of 
caustic potash; ferric gelatine dissolved by caustic potash 
— apt very tough, looking like tallow, with scarcely a 
mell. Araucaria Cunninghamii, Ait 
bb. Rosin more yellow and transparent ; emell of turpentine 
more decided. Araucaria Bidwillii, Hook. ; 
2 — gelatinising with ferric salt t only © on addition 0 
se tash. Grevillea robusta, 
tio: = Part ble j n water stained blue by ‘ferric salt. Dry distilla- 
n Yields py prrogalic (nia — 1). 
1. The C and 
adheres to the fingers, or it can be drawn out into slimy 
= under water and in the air. Tan resins containing 
Nz0ic acid (not 
a. Wate ery As hres of ae pale yellow colour. Eucalyptus 
culata, Hoo 
x esate solntion brown, greenish yellow on conn’ aise 
cyanide of potassium in ammonia makes a TM. 
crimsonan and pink colouration. Eucalyptus tessellaris, .v 
