396 J. H. MAIDEN AND H. G. SMITH, 
with nitric acid and the process repeated. A small quantity of 
mucic acid is usually obtained in this second treatment. 
The portion of the gum soluble in water gives only a small 
precipitate with ferric chloride, nor does it give any marked 
reactions with mercuric chloride, stannous chloride, or with a 
saturated solution of borax. 
The gum is interesting, primarily because it belongs to the 
Rutacez, a Natural Order very few of whose genera have, up to 
the present, been recorded as yielding gums. Commercially it 
cannot be looked upon as a substitute for gum arabic or gums of 
that class, as a Jarge proportion is insoluble in cold water. The 
large percentage of mucic acid formed is very remarkable. 
Melicope neurococca, Benth. (N.O. Rutacez). 
Syn: (Bouchardatia neurococca, Baill.) 
Collected at Lismore, N. S. Wales. 
This gum is in large tears and globular masses of a light amber 
colour, very bright and transparent looking. © It is brittle and 
breaks with a very bright conchoidal fracture. It much resembles 
the gum from Geijera Muelleri, except that this sample is more 
bright in appearance. It also behaves in the same way in water, 
a portion only going into solution, while the remainder is soluble 
when heated in a dilute soda solution. The precipitates of arabin 
and the formation of arabinose, are produced exactly in the same 
way as described under Geijera Muelleri. 
Our sample contained 14-68 per cent. of moisture and 2°54 per 
cent. of ash; this ash is white, and consists of the carbonates of 
lime and Magnesia, with sulphuric and phosphoric acids. Only 4 
slight trace of nitrogen was detected, indicating the almost entire 
absence of albuminoids. 
The yield of mucic acid in this gum was very large, no less than 
42°48 per cent. being obtained. This is remarkably high. Ferrie 
chloride in the portion soluble in water gave no precipitate, and 
only darkened the solution slightly. Other reagents gave 9° 
results, 
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