on the Action of Poisons on the Animal System. % i\ 
independently of chemical action. This led me at first to 
suppose, that when arsenic has passed into the circulation, 
death is the consequence, not so much of the poison disturb- 
ing the functions of any particular organ, as of its destroying 
at once the vitality of every part of the system. The follow- 
ing circumstances, however, seem to show that this opinion 
is erroneous. In an animal under the full influence of arsenic, 
even to the instant of death, some of the secretions, as those 
of the kidneys, stomach, and intestines, continue to take place 
in large quantity; and the muscles are capable of being ex- 
cited, after death, to distinct and powerful contractions by 
means ,of the Voltaic battery. 
Experiment 3. Seven grains of the white oxide of arsenic 
were applied to a wound in the back of a rabbit. 
In a few minutes he was languid, and the respirations were 
small and frequent. The pulse was feeble, and after a little 
time could not be felt. The hind legs became paralysed.* 
He grew insensible, and lay motionless, but with occasional 
convulsions. At the end of fifty-three minutes from the time 
of the arsenic being applied, he was apparently dead ; but on 
opening the thorax, the heart was found still acting, though 
very slowly and feebly. A tube was introduced into the tra- 
chea, and the lungs were artificially inflated ; but this appeared 
* I have observed, that where the functions of the brain are disturbed, paralysis 
first takes place in the muscles of the hind legs ; afterwards in those of the trunk and 
fore legs ; and last of all in the muscles of the ears and face. These facts seem to 
show that the influence of the brain, like that of the heart, is not propagated with 
the same facility to the distant as to the near organs ; and this is further confirmed 
by cases of disease which occasionally occur, in which, although the paralysis is con- 
fined to the lower half of the body, the morbid appearances met with on dissection are 
entirely confined to the brain. 
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