ON A RED RESIN FROM DRACAINA CINNABARI. 629 
mate of cinnamic acid. We have not yet examined the other portion, which is 
undoubtedly a distinct resin. 
In describing the Socotra resin we have already enumerated fully the charac- 
ters of the resins of Class 1V. Wecompared carefully with the Socotra resin the 
specimen from the Kew collection marked “ Calamus Draco, Bombay,” and 
found them to be in all points identical. Combustion gave C 71:89, H 6:17, 
and O 21°74 as the ultimate composition of the Kew specimen. The specimen 
from Dracena Draco belongs, as already mentioned, to our fourth class, and as 
its source is well authenticated, we thought it would be interesting to compare 
it also more carefully with the resin from Dracena Cinnabari, with the view of 
ascertaining if there was any difference in properties answering to the difference 
in species. After a very thorough examination we have come to the conclusion 
that the two resins are identical, or at all events so closely allied as not to 
admit of discrimination by their physical properties. The only considerable 
difference which we could detect was a greater solubility of the resin from 
Dracena Draco in boiling water. 
The result of our work so far as it has gone has been to prove (1) that there 
are several distinct and well defined varieties of resin known under the name 
of dragon’s blood ; (2) that probably each variety is derived from a different 
genus; and (3) that there is probably no difference in resins derived from 
different species of the same genus. Little has as yet been done towards the 
examination of the chemical constitution of these substances. HLastiverz and 
Bartu, by oxidising with caustic potash dragon’s blood, derived presumably from 
Calamus Draco, obtained a variety of aromatic products, including benzoic acid, 
paraoxybenzoic acid, phloroglucin, &c. We propose to extend our investi- 
gation in this direction with a view to ascertain if the resins of the different 
classes yield different oxidation products, and in this way hope to gain some 
insight into their chemical constitution. 
