M. D. — " Dear Sir, about sixteen years since, a large eagle, Falco leuco-
cephalus, belonging to the Linnean Society of this city, was sentenced to
contribute to a cabinet of natural history. A variety of experiments was
made with a view to destroy him without injuring his plumage, and a
number of mineral poisons were successively given him in large doses,
but without effect. At length a drachm of corrosive sublimate of mer-
cury was inclosed in a small fish, and given him to eat. After swallow-
ing the whole of this, he continued to appearance perfectly well, and free
from inconvenience. The next day an equal quantity of white arsenic
was given him, without any greater effect ; so that in the end the refrac-
tory bird was obliged to be put to death by mechanical means. The ex-
periments were made by Dr Hay ward and myself, in presence of other
members of the Society, Very truly, your obedient servant, Jacob Bugelow."
I have now no doubt that in a state of confinement, this species sometimes requires a long series of years before it attains the full adult plumage, by which it is so distinctly characterized. There is now one living in the suburbs of Philadelphia, which was eight years in coming to this state of maturity. Almost every person who saw it, while yet in its brown dress, called it either a new species or a Golden Eagle ! Nay some said that it must be " the pretended Bird of Washington r My constant and most worthy friend, Dr Richard Harlan, took me to see it. I felt assured as to the species, and told him that its head and bill would become white, and that its size, which was rather larger than common, was not such as to indicate a different species. I offered a wager of one thousand dollars in support of my assertions, but the Doctor wisely declined meeting me on this ground. Four years afterwards, when this bird was eight years of age, it moulted, and the head and tail assumed a pure white colour. Dr Harlan, in one of his letters, dated 26th April 1831, says, " I wish I could walk with you this moment to M'Arrax's garden, to shew you how white the head of the eagle, which we talked of betting about, has at last become, as well as his tail ; but he must have been at least nine or ten years old first." This very eagle happened to have each of his middle claws of a whitish colour, and his owner would fain have persuaded me that it was a new bird, on the assertion, as he said, of a well-known ornithologist residing in Philadelphia, who has since published
