THE URARI, OR ARROW-POISON OF THE INDIANS. 465 
was to make it in my presence, ultimately refusing to do 
so, but who was more complacent to the missionary, Mr. 
Youd. The process, as described by my brother, is iden- 
tical with that mentioned in the letter of Mr. Youd, dated 
the 4th of October, 1838, which I have added as a valu- 
able document to my remarks on the urari poison in the 
‘Annals of Natural History. 5 
On his return to Berlin, he took with him some of the 
poison which had been prepared in his presence, which 
Dr. Heintz, of Berlin, has analysed. 
The difficulties of this process, as regards vegetable 
substances, and the patience requisite to perform it with 
accuracy, are well known. I have given samples of the true 
Macusi urari to some of the first chemists of our day, but it 
seems all shrunk from the labour, or really found difficulties 
which deterred them from continuing the process. Dr. 
Heintz did not meet with perfect success. It is the most 
recent analysis of the urari poison, proving like Boussin- 
gault’s the absence of strychnine and of animal substances. 
Dr. Heintz did not succeed in discovering the alkaloid which 
MM. Boussingault and Roulin have called curarine, and 
which MM. Pelletier and Petroz assert they have likewise 
obtained by a process which differs from that of the chemists 
just before named. 
Some very valuable experiments respecting the effects of 
the poison were made by Dr. Virchow and Dr. Miinter, a 
statement of which is added in a note to my brother’s work. 
The most important result of these experiments is the 
observation that animals killed by urari show no difference 
in the appearance of the vital organs on dissection from those 
which were killed by mechanical means. 
With the knowledge of the foregoing facts before me, I 
have been rather astonished to see the old account of snakes’ 
teeth, &c., renewed in an article, entitled 66 Recherches sur 
le Curare,” which, according to the ‘Journal de Pharmacie 
et de Chimie, 5 (tome xix, p. 36), has been read at the Acade- 
mic des Sciences, by M. Cl. Bernard, in his name, and in 
that of M. Pelouze. 
These gentlemen assert, furthermore, that notwithstanding 
this poison had been known for such a length of time, no 
precise notice existed of the nature of the ingredients which 
entered into its composition.- 
I thought that the experiments which I had made at Fort 
San Joaquim would at least have set the question of the 
source of the active principle at rest. 
(To be continued.) 
XXX. 
62 
