OF SASSARUBRIN. 
211 
but acquire a deep crimson when mingled with concentrated 
sulphuric acid. 
Sassarubrin may be produced by the union of the acid and 
oil, provided it be moderated by refrigeration or dilution 
with water. 
Without some precaution, the heat produced is sufficient to 
char the resin more or less. The reddening influence of the 
oils of cinnamon and cloves is due to the generation of resins 
analogous to sassarubrin. 
To those resins the names of cinnarubrin and clovorubrin 
may be severally assigned. Cinnarubrin may be evolved by 
adding oil of cinnamon to equal parts of sulphuric acid and 
water, previously mixed and refrigerated, the temperature 
being subsequently elevated till the mass rises up in a foam ; 
when the whole should be poured into a solution of pearlash, 
from which the resin may be extricated by a strainer. It is 
analogous to sassarubrin, but it is less efficacious in colouring 
sulphuric acid, and does not, like the former, impart to the 
sides of the containing glass a rich red colour. Moreover, 
it appears to be partially insoluble in alcohol, and to retain 
sulphuric acid after being boiled with an alkaline solution. 
I infer that a new series of resins may be evolved from the 
essential oils by their reaction with sulphuric acid; which, 
having a general analogy to each other, may still have discri- 
minating characteristics, arising from the oils wiience they 
may be derived. 
