I was amused the other day, at seeing a paragraph in the London Leader, on "dinners," in which it is stated that Caulaincourt (ambassador to St. Petersburg from Napoleon I.) once gave a dinner, at which, among other features, there were seven pears, which cost 300 francs, $60 a piece. "But," says the writer, "Paris in 1838 hast left St. Petersburg in 1806 far behind. At Chevet's, in the Palais Royal, there are pears in the windows equal in size to small pumpkins. Curiosity the other day prompted me to make inquiries as to the price of some of them, and Madame Chevet politely informed me one might be had for £25, ($125!) They are, however, very seldom purchased, but let out in the same way as plate or chandeliers, to make a show, for 5 francs ($1) a piece." There is a pear story for you, and I have no doubt of its truth from what I saw myself.

It will soon be time for your importers to look about for the best new roses of 1858, and I name for their benefit two or three of great merit. Of hybrid perpetuals, Eveque de Nimes, a crimson, and Triomphe de 1'Exposition, with Colonel de Hougemont, are the favorites. The latter eclipses Baronne Prevost, and supersedes it. Louis Chaix is a superb crimson, descended from Geant des Batailles, and very promising. We have now a better assortment of hybrid perpetuals than could have been hoped for a few years ago, and I trust your amateurs are well supplied with these varieties.

Dr. Lindley notices the new California strawberry, called Fragaria lucida, with the following remarks: - " It was introduced a short time since through M. Van Houtte. Sufficient time having now elapsed to ascertain its qualities, Mr. Sprekelsen, an experienced cultivator at Hamburgh, makes the following report. He is of opinion that great things may be expected of it, and that it will give rise to a new race of double-bearing varieties. Every runner and each branch of the runners forms a strong flower-bud. It moreover, ripens late, that is to say, at Hamburgh, towards the end of July, when other strawberries are over. It is far better flavored than any late English sort. Its fruit is, however, deficient in size, flesh, and juice. The habit of this Fragaria lucida is described as very dwarf, the leaves have very short velvety stalks, of a red color; they are deep green and shining on the upper side, but woolly beneath. There is generally but one flower to a truss, and that is remarkably large. The fruit is sweet, without acid, but a little vinous. The "seeds " are sunk in the flesh. Madame Elise Vilmorin, who has made the strawberry her specialty, is said to expect great things from it.

It is no doubt the same as a plant found by Douglas and called by him Fragaria Macraei, which Sir Wm. Hooker referred to F. chilensis".

The (Economic Museums, at Kew Gardens, are among the roost valuable institutions of this great metropolis. Sir William Hooker's efforts have been crowned by the most ample success and popularity, and are attended with most interesting commercial advantages. They are far more interesting and important than the most sanguine promoter could have anticipated upon their first formation. So huge have they grown that the new museum is wholly devoted to illustrations of the products of Exogens, while the old house is filled with Endogens (or Monocotyledons) and Cryptogamic vegetation. It is hither that students should direct their steps if they wish to know what tropical palm trees are, and to examine at their leisure the thousand curious forms of vegetation of which they can never learn much from books alone. Winter is as good a time as any for the study of museums, and it is to be hoped that the approaching months will be vigorously applied to that purpose by many a young aspirant to scientific fame and social rank.

A new room has been opened at the British Museum, containing an extraordinary collection of foreign plants and seeds - sections of the trunks of trees, showing their structure, and specimens of woods, polished and unpolished; they thus display the variety and beauty of the grain of the woods. One table displays cabinet and other woods, and the woods used by the North Western Railway in the construction of their carriages; and another what may be called the curiosities of botany, such as the efforts of a tree to cover a wound - a spike-nail embedded in oak and covered over with many subsequent layers of wood, etc. This is interesting and instructive, though less so than Sir William Hooker's exhibition of the curiosities of grafting, where much is to be learned by the eye. These exhibitions are to be commended, great results often being brought about by a practical mind viewing the "rarities " of nature's works. How much better than the ever-active energy displayed at Washington in President-making, and trifling debates.

Why, I understood before I left America, that even the plans for planting the public grounds designed by Downing, have been left to take care of themselves, and instead of one good national example of "Park and Plaisance," the majority of the public grounds are growing up with Ailanthus and Abele trees! I write it with shame; the very powder wasted in firing salutes for empty-headed officials, would more than create a fine "Place d'Arms," and keep it forever in order. But the "civilization" which revels in beauty will come in time. [There has been more money wasted in frippery on the new capitol, than would have bought all the ornamental trees for sale in the Union. - Ed. ]

I went down in November, to Chatswortb, to see the revolutions there created by the new proprietor, lately Earl of Burlington. Vast improvements have been made since my last visit. The new wing and elegant offices and entrance have been completed. I got the correct measurement of the new conservatory, which some doubters in America would scarcely credit; it is 278 feet long, 123 wide, and 67 feet high, and the whole appearance is excellent.

By great good luck I had a view of the Emperor Fountain in full play. The jet reached 300 feet in height, and seemed joyfully endeavoring to go higher and higher, and overleap itself.

The orange house is 180 feet long, 27 feet wide, and 21 high, and has very noble trees in full fruit. Sir Joseph Paxton has erected an Anglo-Italian villa near the gardens, and to those bringing proper introductions, is affable and polite; but do not approach him without the "papers." I could fill many letters with my notes, but the space I am confined to will not permit Let every American who visits England see Chatsworth, if he sees little else.

Yours truly, Hortulanus.

London, January, 1859.