66 
The Sterculia gum is dissolved in water on boiling for some days, 
or on boiling in water acidulated with HCl. Alcohol precipitates 
the arabin from this solution. Ferric chloride does not a fe it; 
and the alcohol precipitate is not stained eons yellow by 
By prolonged samy in water with KOH the Stencils vd is also 
dissolved, and in the solution a white precipitate is formed by alcohol. 
The Sterculia a gum is an inspissated vegetable — a higher 
exh e a convertible into true arabin by hydration. 
The Sterculia gum contains only 16 per cent. of w 
erminalia catappa, Linn., Syn. Ql. Fl. 160. vndign Almond. 
ve ed habitat, Fitzroy Island: This Indo-Australian tree 
a gum which agrees in every respect with the bottle-tree gum, 
rae in dry state it looks more like a dark gum than like gum 
gacanth. It is an inspissated Saeanie slime, and contains 18 per 
cent. of moisture. 
astanospermum australe, A. Cunn., Fi. Austr. il. 275. More 
Bay Chestnut or Bean-tree. Exudes a light- brown gum from von 
ie the bark, Ral acegé as the rainy season. It swells i in water, a0 
s partly dissolv ~The watery solution is stained Drown 
reas eutate, owing to a ‘alia vegetable dye. This colouring matter, 
found eet in the bark, is of a ead colour, which one 
| 
4 
; 
Se ee 
Ipha , vs eae 
vi pee. This last precipitate is dissolved again on addition © 
gelatine. Limewater — hg solution of chestnut gum orange; 
copper acetate gives no reac £ the 
This vegetable dye ee eaiy a very small proportion © ae 
. Moreton Bay chestnut gum contains 15 per cent. of arabin 600 
ANALYSIS— 
Arabin Se ee 
eat as ak eee 
Yellow colouring matter... 9... «ss traces 
100°0 
nected Hookeri, F. vy. M., Fl. Austr. ii. 296. ae 7 : 
Ebony. <A brownish yell ow gum in large pieces is exuded by soni 
which is rosteislsl to Queensland and Northern A Australia. It ved. 
mostly of metarabin, and swells only in water without being erated 
ped with ferric salts, and is not gelatinised at all by b 
arabin is precipitated out of the watery solution by alcohol, 
 aeatemtieot is —— only on addition of a larger 4¥ 
a 4 | 
_ The m snc is dissolved in hydrochloric acid 0 ol Sot 
and ae — is precipitated out of this solution by alcohol 
cert an alkali. 
vel 
caustic potash solution- dissolves the metas 
in. oe without staining it much, 
