ON A RED RESIN FROM DRACAINA CINNABARI. 627 
We shall now give a brief account of the chemical character of the resins 
belonging to each class. The resins of all the groups are abundantly soluble in 
alcohol, ether, and oil of cloves,—-the insoluble residue, which in some cases is 
considerable, consisting chiefly of vegetable fibre 
The resins of Group I. are, when powdered, of a brick-red colour,—the colour 
of hematite rather than of cinnabar,—and transmit in thin splinters ruby-red 
light. They melt about 80° C, or nearly 20° above the Socotra resin. Heated 
to their decomposing point they give off highly irritatmg red coloured fumes. 
The alcoholic solution is orange-red rather than blood-red in colour, but has, 
like that of the Socotra resin, an acid reaction. ‘The resin of this class, which 
we subjected to a more particular examination, namely, a specimen from the 
Kew collection marked “ Calamus Draco, Singapore,” contains cinnamic acid, 
which it yields up readily on heating in a sublimation tube. That it is not 
benzoic acid is clear from the form of crystal, as well as from the fact that it 
gives no extract to petroleum ether, which readily dissolves out benzoic acid 
from an artificial mixture. It ought to be mentioned that cinnamic acid is only 
very slightly soluble in petroleum ether. This resin is soluble only to a slight 
extent in strong caustic soda, and dissolves with difficulty even on heating, 
giving an orange-red coloured solution. It is hardly at all soluble in cold 
ammonia and lime water, and only to a slight extent on boiling in these reagents. 
It is insoluble in cold sodium carbonate, and dissolves with difficulty on boiling 
to a reddish-yellow fluid, giving off a smell like rhubarb. In its behaviour, 
therefore, with all these reagents, it differs in a marked manner from the Socotra 
resin. With acetate of lead it gives a brownish-red coloured precipitate, soluble 
in alcohol, but insoluble in boiling water. It is very slightly soluble in boiling 
hydrochloric acid to an orange-yellow solution, from which it is reprecipitated 
by ammonia. It is also reprecipitated by ammonia from solution in acetic acid. 
It is decomposed by strong nitric acid. The ultimate composition of this resin 
is very nearly the same as, if not identical with, that of the Socotra resin. Two 
analyses give the following numbers :— 
(1) (2) (Mean. ) 
C 71:03 70:08 70°55 
H 6°46 6°42 6:44 
O 2251 23°50 23°01 
100-00 ~ 100-00 100-00 
These numbers agree very closely with those given by Johnstone. 
The resins of Class II. differ still more widely from the Socotra resin, both 
as regards their physical and chemical characters. The specimens of the resin 
which we had to work with were exceedingly pure. This variety of resin is of a 
beautiful carmine-red colour, and in thin splinters transmits ruby-red light. 
VOL. XXX. PART III. 5G 
