65 
_ Maerozamia spiralis, Miq., Syn. Ql. Flora 1st Suppl. 49. The 
tones of the Macrozamias exude more or less gum from the peduncle 
| y cut. Gum also collects in the cavity of the stem, when 
nergeh ae the plant is cut off. The gum has already been analysed 
. Maiden. 
It consists of colourless, pearly, tough and hard tears, and swells 
Yery much in water, but nothing is dissolved of it, not even if the 
water is boiled, as neither acidulated nor alkalised aleohol makes any 
05 ag init. Boiled in water with KUH or NaOH, the gum is 
i ; aleohol precipitates the arabin (or metarabic salt) from the 
on. 
In water with dilute HCl the gum dissolves also on boiling, and 
the arabin 18 precipitated likewise by alcohol; on addition of water it 
a again. Ferric chloride does not coagulate or gelatinise 
on. 
ANALYsIs— 
Water... 46 on re ss epee 
Metarabin ... ibe si Cap ae eee 
100°0 
_ Hibiseus heterophyllus, Vent. The gum exuded by this tree, 
which is also found in New South Wales, contains true bassorin. It 
~ Sells very much in cold water, forming a sticky paste like rice-meal 
paste, and altogether different from the granular masses formed b: 
Sterculia gum. The gum is dissolved in water on prolong 
gum is precipitated by alcohol, and the precipitate is stained 
ick ellow on addition of caustic potash. The gum is disso. 
in . 
trap ese teactions indicate the identity of Hibiscus gum with gi 
— Asthe th and its total discrepancy fhdin the gum of the Btorviliae 
: “cer aatgy found only in minute quantities it cannot be put to any 
ANALYsts— : 
ey a 8 
ie. 2 2S ee 
oo | 1000 
3 Bote emia rupestris, Benth., Fl. Austr.i. 230. The Narrow-leaved 
“" oe G. Don., Fl. Austr, i. 229. Kurrajong. 
» idriida, R. Br., Fl. Austr. i. 227. 
. trichosiphon, Benth., Fl. Austr. i. 229. Broad-leaved Bottle- 
yy Ooking like g tate. . 
lt is not dissolved by water, but swells only in it, and forms 
Me ular masses like soaked rice, with no adhesiveness. 
oe acide an adledive 
Paste j ‘ulia gum to gum tragacanth, which yields an a 
2 a Water like that of rice meal. 
