IDENTIFICATION OF THE FALSE ANGUSTURA. 145 
is obtained, " is not yet known, but it is a native of South 
America, and therefore it is not, as formerly asserted, the bark 
of the Brucea anti-dy sent erica which grows in Abyssinia." 
p. 340. 
In Dr. Thomson's last edition, 1833, p. 226, we find 
no further information than a brief allusion in a foot note to 
the existence of the spurious bark, and to Plamba's obsolete 
observations regarding its history and name. — p. 226, edi- 
tion, 1838; 
The first hint we meet of the true nature of this bark occurs 
in the valuable Manual of Materia Medica, by Vavasseur and 
Edwards, in which, p. 269, the authors observe, — "This 
substance, obtained from South America, is probably yielded 
by a strychnos yet undescribed, and not by the Brucea anti- 
dysenterica" &c. 
Lastly, in Dr. Christison's unrivalled work on poisons, last 
edition, October, 1S35, p. 806, we find the author observing — 
" It was long supposed to be the bark of the Brucea anti- 
dysenterica, but the latest inquiries seem rather to point at 
its being the produce of a species of strychnos, and perhaps of 
the familiar species, S. nux vomica" 
Such is a fair outline of the history of this bark up to the 
latest period. Since the last meeting of the Society, I have 
been enabled to clear up all doubts on the subject, and to 
identify the false angustura as the bark of the nux vomica 
tree. 
The subject was brought to my notice by my having been 
intrusted with the analysis of a crystalline substance supposed 
to have been prepared from the bark of the Rohun tree, 
(Swietenia febrifuga.) My experiments showing that the 
crystals were Brucine with traces of strychnine, the presump- 
tion immediately arose that the bark from which the crystals 
were obtained was the bark of the Strychnos nux vomica, the 
only poisonous strychnos abundant in the Bengal jungles with 
which the natives are familiar. 
Specimens of the bark from which the crystals were pre- 
VOL. IV. — NO. II. 19 
