626 DR J. J. DOBBIE AND MR G. G. HENDERSON 
red resins. We soon discovered, however, that much uncertainty prevails as 
to the source of these substances, several distinct varieties of resin being 
described under one name. All the published accounts of the chemical pro- 
perties of dragon’s blood refer to dragon’s blood supposed to be derived from 
Calamus. Draco, but it is obvious from the discrepancies in the statements of 
different writers that some of them must have had in hand resins from other 
sources. To place our comparison upon a sound basis, we collected specimens 
of as many varieties of red resin as possible. Through the kindness of Profes- 
sor BALFouR we obtained a number of specimens from Kew Gardens and from 
the museum of the Pharmaceutical Society. Some of these specimens marked 
“ Calamus ” have characters widely different from those ascribed by FLicki1cER 
and Hanbury to the red resin from Calamus Draco. Beside the Socotra variety 
we had for examination sixteen specimens. We found that all these specimens 
admit of classification according to solubility and other characters into four groups. 
In the first we place those resins which are entirely soluble in chloroform, car- 
bon bisulphide, and benzene. This group includes two of the Kew specimens, one 
marked “ Calamus Draco,” the other ‘‘Sumatra,” the species not being given, 
and one of the Pharmaceutical Museum specimens, also marked “ Sumatra.” 
In our second group the resins are soluble in chloroform, but insoluble in car- 
hon bisulphide and benzene. This group includes two Pharmaceutical Museum 
specimens, one marked ‘‘ Dutch East Indies,” the other “ Pontianak, Dutch 
East Indies,” the source not being indicated. The third group contains resins 
soluble in chloroform and benzene, and partially soluble in carbon bisulphide. To 
this group belong three: Kew specimens, marked respectively ‘ Singapore,” 
“ Penang,” and ‘Calamus Species.” The fourth group includes those resins 
which are insoluble in chloroform, carbon bisulphide, and benzine. To it 
belong three Kew specimens, marked respectively ‘‘ Calamus Draco, Bombay,” 
“Punjab,” and “ Indian Museum,” and two Pharmaceutical Museum specimens, 
one marked “ Probably from Calamus,” the other “ Dracena Draco.” The 
source of the last mentioned specimen is well authenticated. The resins in the 
first group have the characters ascribed by FLUckIGER and Hansury to the resin 
from Calamus Draco. The resins in the fourth group agree in properties with 
that from Dracena Cinnabari. All the Kew specimens are believed to have 
been obtained from species of Calamus, but it is obvious from an examination 
of the above list that some of them must have a different origin, unless, indeed, 
as is very improbable, the same species yield different resins in different 
localities, or at different seasons. Possibly, as suggested by Mr Hos, of the 
Pharmaceutical Society’s Museum, some resins exported from Bombay were 
imported in the first instance from the East Coast of Africa, and not from the 
‘ast Indies. Thus it is easy to understand how resins derived from widely 
different sources might come to be confounded with one another. 
