164: HYOSCYAMUS NIGER. 
nitrate of mercury gave the largest: ete in. 
my experiments. 
The Hyoseyamus has long been iba as a 
narcotic poison. This character it uniformly ex- 
erts in regard to mankind, although many brute 
animals are exempt from its influence.* Diosco- 
rides speaks of it as producing drowsiness and de- 
* Horses, goats, sheep and swine are said to eat it without inju- 
ry. Brute animals are frequently less susceptible of the influence of 
poisons than mankind. In the experiments which have been made’ on 
them to test the effect of doubtful medicines, the positive evidences 
of activity which they furnish, are in general more to be depended 
on, than the negative. That is, if an animal suffers from the action 
of any substance, a man would be like to suffer somewhat in the 
same way. Yet if the animal escapes with impunity, it does not fol- 
low that the man would be equaily fortunate. ‘There is scarcely any 
narcotic plant which is not devoured by some species of quadruped. 
Professor Pallas has stated, that the hedgehog can devour Cantharides 
by hundreds without inconvenience, whereas one of these insects may 
occasion serious trouble to a man. . The following case happened un- 
der my own observation. A large eagle, ( Falco ossifragus, ) intend- 
ed for a cabinet of natural history, was subjected to a variety of ex- 
eriments, with a view to destroy him without injuring his plumage. 
A number of mineral poisons were ‘successively given him without 
effect, even in large doses. At length a drachm of corrosive subli- 
mate of mercury was inclosed in a small fish and given him to eat. 
After swallowing the whole of this, he continued, to appearance, per- 
fectly well and free from inconvenience. The next day an equal 
quantity of arsenic was given him without any better success. So 
that in the end, the refractory bird was obliged to be put to death by 
mechanical means. 
