55 
yt ‘ ‘ 
linifolia bark gives a precip. with ant. tart. alone; the other wattles 
only with NH Cl.) Copper sulphate light brown precipitate, 
darkened by ammonia. (A. mollissima, light brown with CuSO,, violet 
blue like catechutannin with ammoni ia.) imewater greenish-yellow 
to greenish-brown (A. mollissima purple). Ammon. mo olybdate in nitri¢ 
acid light-brown, like the barks. Picric acid in ammonia, violet. 
Sat NaOH, NH,OH, greenish brown. Pot. cyanide greenish- 
with a pink tint. The tannin precipitates gelatine and the 
alkaloids, and yields a brown-red phlobaphene on boiling with dilute 
HCl. Dry distillation yields catechol. The colouring phlobaphene 
contained in the brigalow gum is of a browniab-yellow #2 colour. Acids 
make it lighter, alkalies change its colour to brow 
_ The acid taste of the brigalow gum is due to en and tartaric 
acids were found out as follows: ae the brigalow-gum 
ol (acidified with acetic acid) lead acetate W s added in excess. 
The precipitate was filtered off, the lead eliminated (by HS) 
from the filtrate, the gorges filtered off again, the second filtrate 
treated with alcohol to get rid of the arabin, the third filtrate concen- 
trated, divided into several portions and examine 
- To one portion lime water was added in “the cold. Acslight 
gelatinous precipitate separated immediately. This precipitate, when 
Washed and heated in a test tube with a drop of dilute ammonia @ and & 
crystal of silver nitrate, gave the brilliant mirror characteristic of 
seg acid, 
N 2. Chloride of calcium in excess Was added to a — portion. 
eae precipitate was formed, indicating absence of oxalic ac 
. Chloride .of calcium was added to a third oaHion just to 
e the reaction, and then alcohol was added, when a white 
Precipitate of malic acid was formed. 
ALYSIS— 
i — 7 7 
ee ine 
? = ee ee ee eS 
Bae Ni a ag ae etc 2 18°0 
Brigalow ow arabin, n, gelatinising ‘with Fe, Poa a tena eee oa att oe 
Soluble phd °phloba oon tot 
‘Sees d Malte a acid (only estimated by evaporation to digoes) “B 80 
7000 
Ob The highest amount of catechutannic — see La dark-brown . 
a ie meta gum was 9 percent. The arabin he gum is never turne 
. petarabin by the effects of the sen. (like the gums of the 
ypts are 
ag = tr i 
— moniter a Fl. cor as been mention oF by Mr. 
urity. 
80 ag "The Bombax gum wa alterations a atmospheric influence 
8 to become nearly reer ble (metarabin) in water. | 
