It is a gratifying feature in American experiment, that where pains be taken, and a corresponding expense be indulged, our gardeners equal, if they do not excel, in the luxuriance of display, and the delicacy in flavor of their productions, the corresponding examples in England, the land of all perfection in developing the most successful results in almost everything which they, the English, undertake. Artificial heat and ventilation there supplies the advantages of sunshine and air to an otherwise over-loaded atmosphere of cloud and vapor, and the more gorgeous and luxuriant plants of the vegetable world are exhibited in all their native grandeur and magnificence. Thus the English succeed in producing many articles of luxury to them, which our most negligent people often have in profusion in their ill-worked gardens.

The journal - (for it is truly a journal - the stated accounts which Mr. Meehan has given of the progress of this noble flower of Mr. Cope's,) of the Victoria Regia under American cultivation, is full of instruction to all interested in the progress of floriculture in the United States, and Mr. Cope is entitled to the gratitude of every lover of this most agreeable branch of gardening, for his liberality and public spirit in introducing its cultivation among us.

Victoria Regia #1

Gold and silver fish, it has been proved, are of great importance to the perfect development of the leaves, by devouring the numerous aphides and insects that often infest their under surfaces. Hundreds of these fishes, therefore, may be annually placed in a tank soon after planting. The introduction of the Limncea stagnalis, or water snail, has also been recommended, as it devours the slimy and mucous matter that always accumulates more or less in the tanks of tropical aquariums, and from experience of their usefulness in a large reservoir which contains some thousands, their introduction, in a sanitary point of view, would be extremely beneficial.

A novelty respecting the Victoria in England, is interesting. It is the cultivation of the plant in the open air at the exotic nursery of the Messrs. Weeks, at Chelsea, where it was grown, and flowered to considerable perfection during the summer of 1857, in an open tank, protected by an awning; not, however, in such a strictly natural state as the words "open air" may imply, for the water of the tank, it appears, was maintained at a temperature of 840 or 850 by a circulation of hot water below it. Still, we are far from being convinced that the plant is capable of being grown in the " open air" in England; and the complete failure, too, this year, of the plants in the marble basins of the greenhouse division of the Crystal Palace, tends even more strongly to confirm the opinion of the utter impossibility of attempting to acclimatize a tropical plant of this description.

Sir William Hooker admits that this plant does better in our tanks in the United States, than at Kew. In Philadelphia, we are much gratified to report the entire success of the new Victoria Regia house, lately erected by James Dundas, Ksq., at an expense of some four thousand dollars; such liberality deserves more than a passing notice. Mr. John Pollock, his intelligent gardener, informs us that flowers bloomed exactly six weeks after planting, from a root in the new tank, which is 24 by 30 feet; the house is extremely well lighted, and the tank is set out with a variety of healthy plants suitable to the scene; the whole presents one of the most beautiful sights that can be created by the art of man. The great Palm-house, too, has a tropical air nowhere else to be seen here. We feel quite proud of having such costly and well-cared for establishments in our midst, and of such gardeners as Mr. Pollock.

Novelty is the order of the day. We are to have a ship that will not create nausea, and perhaps a telegraphic cable to America. The horticulturists must not lag behind, and are not disposed to do so. We cut the following from the London Chronicle: