THE URARI, OR ARROW-POISON OF THE INDIANS. 461 
Medical Gazette’ of June \1, 1842. I therein stated, that 
I had detected arsenic in sulphate of potash and also in alum, 
made, by the aid of pyrites sulphuric acid ; and I suggested 
the probability that food might, consequently, in some 
instances, be contaminated with arsenic, as alum is often 
used by bakers in the making of bread ; remarking, also, 
that vinegar is often adulterated with sulphuric acid. — 
Medical Times and Gazette. 
THE URARI, OR ARROW-POISON OF THE INDIANS OF 
GUIANA. 
By Sir Robert H. Sciiomburgk, Ph.D. 
[Continued from p. 409.) 
From what I learned from the Macusis and Wapisianas, 
during my first expedition, they use the bark of the woody 
parts of the Strgchnos toxifera and its alburnum, both of which 
are considered to possess the poisonous principle in the 
highest degree. Young shoots are not employed for that 
purpose. The bark, after having been stripped from the 
wood, is pounded and steeped in water, to which effect a 
new earthen vessel is employed. Here they allow it to re- 
main for some days, well covered, until the water is of a yel- 
lowish colour, when it is filtered by means of a simple 
mechanical operation. Several other plants have been mean- 
while procured, of which infusions are made in a similar 
manner, which are added to the urari at the moment it has 
been concentrated on a slow fire to the consistency of a thin 
syrup. The addition of the juices obtained from the other 
plants gives a darker colour and greater consistence to the 
urari, which, wdiile still fluid, resembles thick tar. It is now 
put into small calabashes, which are covered wdth leaves, to 
prevent the poison from coming in contact w 7 ith the air. If 
it is to be used, the quantity required is put into a calabash, 
and a little juice of the cassava is added, to render it more 
pliable. I w 7 as told that the addition of cassava-water, as the 
expressed juice of the root of the Jatrophia manihot is termed, 
reawakens the slumbering powers of the poison, should it 
ha/e lost its strength by age. After this juice has been 
added to it, the Indian buries the calabash with the poison 
for a day or tw 7 o under the ground. 
This is the simple account of the preparation of the urari* 
