Experiments with Urari Poison. 
359 
“ The opinion has been recently expressed, particularly by Oesterlen (Handbuch der Heil- 
mittellehre, Tubingen. 1845, p. 853) that the American arrow-poison Urari (Woorara, Oester- 
len) and Curari (apparently identical with Urari) undoubtedly contained strychnine, and were 
said to produce quicker paralyses, but on the other hand less convulsions and cramps of the ex- 
tensors. In spite of the second part of the assertion, which contradicts the first, Oesterlen in- 
cludes the so-called arrow-poison, under the section of Pure Tetanica, Spinantia, under which 
are to be found Nux vomica, Strychnine, Brucin, Cocculus indicus, and Faba St. Ignatii. 
“ It appears now, however, from Dr. Heintz’s analysis that there is no strychnine at all in 
Urari, although the physiological effects adduced by Oesterlen appear to correspond with Wa- 
terton’s observations and your own. As we, however, have had the advantage of making direct 
trial with the poison itself, we gladly seize the opportunity of reporting in more detail on the 
toxic effects and final post-mortem appearances of Urari. In spite of the material, according 
to your own showing being already five years old, and notwithstanding the opinion of the Ma- 
cusis, that it loses its essential properties within a space of two, we found it still so drastically 
effective that we all had the reason to guard ourselves against getting poisoned. 
“ Out of the still very firm extract of a brown-black colour and brittle consistency, we made 
a solution of O.G7 grammes to the dram of distilled water. A few drops of this concentrated 
solution was diluted with several ounces of distilled water and the undamaged hind foot of a 
frog held in it for 20 minutes : during this time the limb was sprinkled with a few drops of the 
concentrated solution, so as to give every opportunity for absorption to take place. But as the 
frogremained without any change we thought that the poison, so carefully applied, must be non- 
effective, or else that, according to your expressed opinion, its powers had really diminished and 
took longer to act. Within a quarter of au hour the creature was jumping round about all the 
more lively, and had apparently suffered nothing. 
*■ We accordingly let a drop of the concentracted solution fall into an open serous 
cavity on the creature’s right shoulder-blade : in the course of 6 minutes it tumbled on its 
front legs, which it placed flat on the table, whereupon the hind-quarters fell upon the 
outspread hind-legs and the frog was dead. On applying mechanical irritation, no convulsions 
followed : striking the board on which it lay produced no reflex action. A solution of strychnine 
inserted drop by drop in the wound of the already paralysed animal proved entirely 
without results. 
“ Ten drops of the same poison-solution were poured into a freshly cut wound in the 
neck of a rabbit. Before the end of three minutes, the animal sank altogether in a heap, 
involuntarily bent its head to the ground, where its front legs lay limp : this was followed 
by a few weak contractions of the flexors of the hind extremities, as well as by a peculiar 
motion of the under-lips, although these movements soon subsided. The heart-beat first 
of all stopped, then became regular again, its strength failed, and at the end of the seventh 
minute could no longer be felt. The thorax was opened, the auricles were still contracting, 
though weak. We accordingly performed tracheotomy and maintained respiration by 
blowing air into the wind-pipe, when the heart at the same time commenced to contract, 
violently, the auricles indeed more than the ventricles. After keeping up artificial respiration 
for (j or 7 minutes, when the experiment was interrupted, we noticed the auricles still 
contracting in the 20th minute. Opening the heart for the first time on the following day 
normal blood-clots were found : the animal was in a state of rigor mortis. 
“ Another rabbit had a skin-wound an inch in length made in the middle down its back 
and twenty drops of the concentrated solution poured into it. The animal yet eating a 
little while subsequently to the operation, let its head drop involuntarily at the end of 12 
minutes, the hinder portions of the body together with the outspread fore-feet lying limp 
upon the ground. Fifteen minutes after the administration the animal did not stir when 
pulled by the ears, and when held up by the same the extremities hung down limp and loose : 
the heart however still beat, at first in longer intervals with a short double-beat, then became 
regular, % to a minute, but after 20 minutes could no longer be felt. On opening the animal, 
straightway, it showed nothing in the way of blood-clots in the smaller or larger veins. The 
blood removed from the heart itself was still fluid, without alteration of colour, but clotted 
in a few minutes like the blood of slaughtered animals. The blood corpuscles were unaltered. 
The internal movements continued for some time longer. But while the ordinary muscular 
substance was still inclined to contract at the spots directly irritated, nerve irritation produced 
no motor signs. 
*The above specified solution was also applied to the poisoning of a cat. VVe made a 
skin-wound 1) inches long over the right shoulder blade, poured 10 drops of the solution 
into the wound, and let the loosened animal run about freely after the operation. While running 
around the room so sprightly, it crept to our great regret into the unknown piping of an 
empty stove that happened to be there. It was only got out 20 minutes later when it lay 
paralysed on the flooring boards. The head remained in any random position in which it was 
put, but the flexors of the extremities contracted frequently and briskly, the heart at first 
beat 88 to the minute and gradually stopped, though later than the contractions just 
mentioned. Tracheotomy was now performed, and artificial respiration kept up 
for 28 minutes, with the result that the heart commenced to beat afresh with 2G4 to the 
minute. However, there was no return of the sensory functions or motor effects, but on 
the application of a powerful mechnical stimulant, the animal’s muscular system showed 
contractions. 
From these experiments of ours we believe it must be now admitted : — 
(1) That Urari, after being preserved in a dry condition for five years has an inten- 
sive and rapid action even in small doses, 
