One day nearly a year ago, a young member of our household brought home three small fishes (the common dace), and begged so hard that the globe might be brought out, and converted into the family fish-pond once more, that we finally consented, and the little fishes were soon at home in our library window. Not more than a week after this, a genuine mud-turtle was added to the collection, and, strange as it may seem, these little creatures have lived at peace with each other ever since.
We covered the bottom with a few pebbles from the brook, and afterward added some sand and a handful of shells from the sea-shore.
We experimented with several species of water-plants, but were convinced that a tiny fine-leaved plant, of which I have forgotten the name, but which grows very plentifully in our northern fresh-water brooklets, and the vallisneria Spiralis, or common tape or eel-grass, gave the greatest satisfaction on the whole. With these little plants growing on its bottom, we are not obliged to change the water for several days at a time.
In bright sunny weather the plants give forth plenty of oxygen for the fishes to breathe. This can be readily seen by noting the little air-bubbles adhering to the leaves and stems, or rising slowly to the surface of the water; but in cloudy weather this gas-making process diminishes, so that after awhile the air becomes vitiated, and the fishes, finding it hard to breathe, are forced to swim near the top, with their heads at the surface of the water. At such times it is well to introduce fresh air into the water, by filling a cup with the water, and, holding it an inch or two above the surface, pour it slowly back into the globe; by repeating this process several times the water is made comparatively pure once more. Another and easier way of accomplishing this is by using a small syringe instead of the cup; but care must be taken in either case to avoid hitting the fish with the descending stream.
Their food consists of angle-worms and flies in summer, and bits of fresh meat cut very fine with the scissors, during the colder portions of the year.
THE SALT-WATER AQUARIUM.
The globe answers equally as well for salt as for fresh water fish, provided its inmates are not crowded and are supplied with a sufficient quantity of good sea-water. In obtaining this supply, it is desirable to have it dipped from deep water some distance from the shore, or from the channel if possible.
In preparing your globe, put a handful of gravel and sand on the bottom, then with three or four irregular stones build a cave or little arch, for the fishes to play beneath.
Although some authorities say that the aquarium should be kept in the shade, the one with which the writer was familiar through childhood always stood in a south window, which was only partially shaded by some great trees in the garden beyond.