Among other remarkable objects in the museum of natural history we recognized, swimming upon his shingly bed under a glass case, our old friend the Gymnotus Electricus, or Electrical Eel. Truly, he is a marvelous fish. The power which animals of every description possess in adapting themselves to external and adventitious circumstances, is here marvelously illustrated, for, notwithstanding this creature is surrounded by the greatest possible amount of artificial circumstances, inasmuch as instead of sporting in his own pellucid and sparkling waters of the river Amazon, he is here confined in a glass prison, in water artificially heated; instead of his natural food, he is here supplied with fish not indigenous to his native country, and denied access to fresh air, with sunlight sparkling upon the surface of the waves—he is here surrounded by an impure and obscure atmosphere, with crowds of people constantly moving to and fro and gazing upon him; yet, notwithstanding all these disadvantageous circumstances, he has continued to thrive; nay, since we saw him ten years ago, he has increased in size and is apparently very healthy, notwithstanding that he is obviously quite blind. This specimen of the Gymnotus Electricus was caught in the river Amazon, and was brought over to this country by Mr. Potter, where it arrived on the 12th of August, 1838, when he displayed it to the proprietors of the Adelaide Gallery. In the first instance, there was some difficulty in keeping him alive, for, whether from sickness, or sulkiness, he refused food of every description, and is said to have eaten nothing from the day he was taken, in March, 1838, to the 19th of the following October. He was confided upon his arrival to the care of Mr. Bradley, who placed him in an apartment the temperature of which could be maintained at about seventy-five degrees Fahrenheit, and acting upon the suggestions of Baron Humboldt, he endeavored to feed him with bits of boiled meat, worms, frogs, fish, and bread, which were all tried in succession. But the animal would not touch these. The plan adopted by the London fishmongers for fattening the common eel was then had recourse to; a quantity of bullock’s blood was put into the water, care being taken that it should be changed daily, and this was attended with some beneficial effects, as the animal gradually improved in health. In the month of October it occurred to Mr. Bradley to tempt him with some small fish, and the first gudgeon thrown into the water he darted at and swallowed with avidity. From that period the same diet has been continued, and he is now fed three times a day, and upon each occasion is given two or three carp, or perch, or gudgeon, each weighing from two to three ounces. In watching his movements we observed, that in swimming about he seems to delight in rubbing himself against the gravel which forms the bed above which he floats, and the water