POISON OF THE UPAS ANTIAR, 
449 
muscles and nerves, on the contrary, it is easy to show that 
the ligature or excision of the heart has not the same in- 
fluence as the Antiar, inasmuch as, in the first case the 
muscles and nerves are found irritable six or seven hours, 
and more, after the experiment has been made. Therefore 
it may be said that the Antiar has a direct action on these 
organs. 
These points once demonstrated, there remained one more 
question to elucidate, namely, whether the Antiar acts only 
upon the muscles, or also upon the nerves. If we consider 
that the Antiar undoubtedly paralyses the muscles, we may 
easily see that the loss of the excitability of the nerves 
possibly depends merely upon the impairment of the mus- 
cular contractility, and is therefore not real, but only apparent. 
With a view to determine the real state of things, I tried a 
third series of experiments — poisoning frogs in such a man- 
ner that the muscles of one limb were kept free from the 
influence of the poison. This was done in two ways : first, 
by putting a ligature round the crural artery and vein of one 
leg; and secondly by cutting through a leg entirely, after the 
ligature of its vessels, with the exception only of the ischiadic 
nerve. In poisoning frogs treated in one of these ways, through 
a wound of the back, I found that, with the exception of the 
heart, the Antiar acts in the first instance upon the muscles. 
This is shown by the fact, that in the second hour, at the 
time when the muscles of the poisoned parts have lost their 
irritability, the nerves of the sacral plexus in the abdomen 
still possess their full influence upon the muscles of the leg 
which have been kept free from the action of the poison. One 
might be inclined from this to conclude, that the nerves are 
not at all acted upon by the Antiar; but this inference would 
be erroneous. In fact, the experiments just mentioned, if 
followed a little longer, show that in the third or fourth hour 
the sacral plexus also becomes inactive, at a time when the 
muscles of the non-poisoned leg are fully contractile. The 
Antiar, therefore, paralyses also the nervous trunks, but later 
than the muscles. 
From all these experiments, it seems to follow that the 
Antiar is a poison which acts principally upon the muscular 
system (the heart and the voluntary muscles), a conclusion 
in favour of which I may further add, that the muscles and 
the heart of frogs poisoned by Urari (Woorara Curare) lose 
their irritability totally, and in a short time, if Antiar is intro- 
duced into a wound some time after the Urari. If we 
consider that, as I have shown (see Proceedings of the Royal 
Society > 1856, p. 201), the Urari only acts upon the termm- 
