Mr. Editor. - The gardeners of America should be interested in what is transpiring here, as well as in their own country. True, the climate is somewhat different, and practice has to vary accordingly; but it is also true that the efforts to procure new plants from all parts of the world, aided, as they are, by the steam marine of this country, often present us with novelties that your gardens should possess; and there is a great amount of intelligence and capital engaged in horticultural pursuits. In fruit culture and an extended knowledge on that topic, the people here may learn of you. So, while an interchange of knowledge is going on, a note now and then may not be unacceptable to your readers. The Horticulturist is sprinkled about among our amateurs, and is much read. The American subscribers sometimes forward it to their friends, while others are regular subscribers.

Kew looks better than ever, and is wonderfully attractive to all who feel an interest in botany or gardening. The season of flower-shows at the Crystal Palace is over, but these exhibitions have been among the most attractive and profitable to the Company, while their large premiums have stimulated rivalry, and enriched the successful competitors. The Palace company is not pecuniarily successful, but there is a pride felt in its results that will keep it going.

It is not a little remarkable, that while the palace does not pay, another company has issued a prospectus for a second, to be placed where it will be more accessible to the great body of Londoners.

The Messrs. Henderson, at St. John's Wood, have recently received many new camellias from China, and great interest is felt for the novelties expected to be found among them when they bloom. These gentlemen are especially successful in the cultivation of Lapegeria rosea, which I do not remember to have observed frequently in America; they plant them in a mixture of rough pieces of turfy loam, peat, leaf mould and sand, when they throw out shoots like asparagus, rejoicing in warmth, and very vigorous. Mandevillia suaveolens, planted in a border with a south aspect, becomes a lovely climber; here it requires only the protection of a little dry hay and a mat during winter, if the soil is drained. The Gardenia citriodora is proving very valuable, and the mules or crosses between Gloxinias and Gesneras, are attracting attention.

It may be new to some of your readers to learn that strawberries are readily produced from cuttings.' A gardener having prevented his forced plants from throwing out runners, shook them out of their pots, and divided the crowns, making two, and sometimes three cuttings of one old plant. The roots were pruned away, and the old leaves also, and each cutting was put into a small 6's pot, in leaf soil and loam, placed in a frame, and kept close for a week; they soon commenced to grow when more air was given. In three weeks they were fully exposed, having then filled the pots with young roots, when they were planted in fruiting-pots, and are now in no way inferior to plants from layers. The strawberry may be propagated in this manner when desirable. Vilmorin, of Paris, has just sent out a new strawberry catalogue of new and old kinds; the whole comprises 74 sorts. For forcing he recommends Myatt's, Queen Victoria, Black Prince, Princess Royal, Sir Harry, and Keen's Seedling; among others, not for forcing, he recommends Elton Pine, British Queen, Omar Pacha, Kitley's Goliath, and Nimrod.

We have a novelty in a Lattice plant, the Bernieriana, dfffering somewhat from the Fenestralis, chiefly in the leaves being larger (from one and a half to two feet) and narrower in proportion; the reticulation being smaller and the color a brighter green. It is from Madagascar. The Horse Chesnut of California, AEsculus Californica, is attracting attention. It is very ornamental, and if hardy will prove an acquisition to the shrubbery; the leaves are smaller than the old kind, and the blossoms more numerous; in dense spikes, greenish white. The beautiful Datura Wrightii with its enormous flower, white shading into lilac, is a great favorite, and Clematis lanuginosa is much employed.

One of our best conducted London papers estimates the refuse of London is worth ten millions of dollars a year, but the state of dilution in which it exists is a bar to its extended use; more the pity, for while we go to the great expense of importing guano, an equally valuable fertilizer is thrown away. Efforts are however making.to retain the refuse of certain factories, slaughter houses etc, and to make it into artificial manures, on whose strength the chemists keep a bright lookout.

We are here much in the same condition with regard to the Chinese Yam as yourselves. There are many who think well of it, and probably I may soon report it as a success.

You will probably see in the English Journals an account of some enormous Perry pear trees, but lest you should not, I copy it as follows: -

In one orchard there are now growing 10 sound Perry Pear trees, whose average circumference three years ago, at between 2 and 3 feet from the ground and below the graft, was 9 feet 4 1/2 inches, but taking the three largest trees separately, above 11 feet; the circumference of the largest tree was 11 feet 3 inches, that of the smallest (of the whole number), 7 feet 4 inches, and they are all of them of the very fullest height and span, the span of the largest 60 feet. A few years ago the largest branches of the largest trees, for a sadly fallacious reason, were cut off, before which unjust treatment they produced an average crop of a ton of Pears of the noble kind called Huffcap, the flavor of which, though rough and wild, is full of fine aroma; but one of them, and not the largest tree, is known to have yielded in one season 2 wagon loads==20 sacks==100 bushels==2 tone=4 hogsheads of Perry Pears".

Steam plows are the talk in Agricultural circles, and are considered moderately successful. We rather look for their improvement to come from America.

I sent from Paris a box of French pears, which I trust arrived in good order. [Yes, in the main, though one third were decayed. They were large and fine, some specimens especially. Ed.] You would scarcely know Paris; the last few years have produced an immense change. The Bois de Boulogne, extending from the Triumphal Arch five miles, is wonderfully remodelled and embellished, and is well kept; it may be considered, notwithstanding its want of large trees, the most ornamental piece of ground in Europe for .its size. There is a mass of artificial rock-work on a gigantic scale; the rocks were taken from Fontainbleau, are of immense size, and most artistically put together. The grounds contain a good piece of water, but the banks want boldness. The climate here is more favorable to bedding-out plants than that of England, and the gardeners do certainly understand how to blend colors; their plats are a blaze of glory. You will be surprised to see the asparagus plant used for ornament; but so it is: they plant it quite young, between rows of bulbs, and the feathery spray of the grass forms a bottom to the beds, and hides the long stems of the flowers, besides forming a good contrast.

I wish you could see some of the new orangeries erected here lately, especially that of Baron Hothschild at Suresnes near Boulogne; where he has magnificent gardens, and the finest " ribbons," without the formality of the English. One border had an ivy edging 12 inches wide; next a row of Phlox Drummondi pegged down; next white petunias; then scarlet geranium, followed by the orange erysimum and white chrysanthemum, backed by blue salvias and gladiolus, which formed the centre of the bed.

I shall occasionally drop you a letter, and am as ever, yours, Hortulanus.

London, December, 1858.