Page:Hardwicke's Science-Gossip - Volume 1.pdf/204

Fresh-water Aquaria.—I shall feel much obliged if you or any of your readers can give me a few hints about fresh-water aquaria. My first difficulty is with minnows, which are always stirring up the gravel in search of food, and the water is filled with a cloud of white particles, which, under the microscope, appear like masses of fibre swarming with Infusoria. I washed the gravel and weeds most carefully before putting them in, and have tried changing the water without success. The white cloud completely spoils the aquarium, and I fear may injure the fishes, though at present they seem in perfect health. I feed them on vermicelli, which they eat greedily. I should be glad to know if animal food is essential, and what kind to use, for I cannot procure the small red worms recommended in books, and the supply of young snails, &c., from my glass jars is barely sufficient for the stickle-backs, which will not eat anything else. I have been advised to leave them without food; but I cannot think the Infusoria in the water would be sufficient for them, and am afraid to introduce snails, beetles, &c., lest they should die, and lie hidden among the gravel to do mischief. The stickle-backs do not stir up the gravel, and the water in their vase is quite clear; but they do not live more than a few weeks, even when alone, and so unable to fight. My caddis-worms also die after a short time, and I do not know how to feed them. I should be glad to know whether a piece of charcoal kept in the aquarium is of any use in purifying the water.—F. C.

Insect Vivarium.—Knowing the horror with which some people regard killing insects, and yet like seeing them more closely than on the wing, I should suggest a vivarium, one of which I have kept for more than three months. It is made thus: the bottom of slate, like that of an aquarium, only pierced with holes for drainage. The height is 2½ feet, and the breadth 1½ foot; halfway up a division is made in the glass, the upper piece of both front and back lifting up like a window; the sides are composed of perforated zinc, painted a pretty light green. Put any pretty fancy top you like, only it must be made of zinc like the sides, for the sake of the air. Plant it with any flowers you like; ferns mixed in look very pretty, and three bird's nests suspended from the top greatly add to the effect; they do best filled with flowers which do not require much water. About every other day take out one window and put a piece of net over instead to air it. I have had several Burnet moths, and now have a Tiger mouth, and a Humming-bird moth, and Bees do very well in it.—E. H.

Cinders in Cultivating Ferns.—Having been asked why, in the fifth number of Science Gossip, I expressed a preference for cinders in the propagation of ferns from seed, I would remark that sandstone almost invariably contains the germs of fungi which hinder and very frequently prevent the development of the fern-spores, and peat, unless prepared by dipping in boiling water, and thus destroying all vegetable life therein, is open to the same objection. Now, if cinders (which, if fresh, contain no fungi) are used mixed with a suitable quantity of peat subjected as above, the ferns will have a fair chance of proper development; for it is highly improbable fungi will obstruct their growth. I have found that peat, if used alone, becomes soddened; and as ferns, like all other plants cultivated in pots, require good drainage, that essential is obtained by the use of cinders mixed therewith.—Helen Watney.

New British Sea-Anemone.—Mr. P. H. Gosse has described and figured a new species of anemone which he considers entirely new (Ann. Nat. Hist., No. 91), and which he has named Ægon Alfordi. "Here is an anemone with high standing column like an Aiptasia, but with the surface warted, and with tentacles like the richest green velvet, throwing into the shade the brightest of Antheas. Moreover the tentacles are of the same colour to their very tips, without the least tint of pink or purple." To which is also added, "Several circumstances indicate that this charming species is very eligible for the aquarium."

Aquarium Difficulties.—It certainly is no easy matter to keep an aquarium in good order. I had one for a considerable time, in which plants, animals, and fish did very well. I used to keep a condensing syringe with a small tube to reach the bottom of the tank, and every now and then in the day, if I went near, sent a stream of air through the water, which not only agitated the water, but stirred up any injurious matters, which I removed with a small find muslin net. The fish seemed quite indifferent.—E. T. Scott.

Streams in Aquaria.—Mr. E. Edwards, of Menai Bridge, has written us taking exception to the remarks of Mr. Alford Lloyd at page 118, in which it is stated that "Mr. Edwards has announced that he makes a machine to answer this purpose, but nothing has come of it." Mr. Edwards requests the data for this assertion, and adds—"my apparatus is all that is required for the purpose intended. I do not claim any new invention in its construction, but such a combination of old principles so arranged as to cause it to do its work in an efficient manner." We insert this in justice to Mr. Edwards, without any desire to open a controversy on the subject.