The following is an extract of a letter to the Committee of Patents from W. D. Brackenridge, late public gardener in Washington, and formerly of the U. S. Exploring Expedition, residing at present at Goranstown, near Baltimore, Maryland: " The two small tubers of Dioscorea batatas which you gave me last spring, I started in a hotbed, and planted them out about the middle of May, in a deep, yellow, loamy soil. About the middle of November I dug the roots, and found two of them over two feet in length, and four inches in circumference. Next season I intend to plant these roots and the small tubers propagated from the leaves, and allow them to remain in the ground during next winter, as I think, in a second year, they will attain a large size, after protecting them from frost by covering with straw or leaves." So says the Country Gentleman. Mr. H. A. Dreer, of this city, has received a supply of this plant from France, of his own importation.

The Dioscorea #1

It will be remembered that la6t year, Dr. Hollick, of Staten Island, New York, promised to give our readers the results of another season's trial of the Dioscorea. We have his statement, which we consider very favorable, and shall give it in the next issue. Meantime, he has sent us a few tubers to distribute to different climates. The time of planting, at New York, was the 23d of March.

The Dioscorea #2

The reader will find in the present number Dr. Hollick's article on this esculent, which is quite a favorable one. From another section of country - Virginia - we have also a good report. Mr. Oliver Taylor, of Loudon county, Bays: "Having grown this potato each season since 1856, and tested its quality and productiveness, we now offer it to the public as a very great acquisition to the list of table vegetables. Being perfectly hardy, having stood the winters of 56 and 57, and equaling if not surpassing the Irish potato in quality and productiveness, it doubtless will take the place of that vegetable as soon as it becomes disseminated. The form of the root is club-shaped, from one to two feet long, the largest end down, and weighs from one to two pounds the first year, and if left in the ground for eighteen months the yield is three times greater. They can be dug for use the year round, and if stored away for winter use seldom rot or sprout in the least. A sandy or alluvial soil is preferable, but in any case it should be deep, as the roots descend straight down, which, with the tops being rather small, allows them to be planted very close. Small tubers are formed on the vines at the axil of the leaves, which grow into the ground and form suitable roots for planting.

The eyes are very small and very numerous, hence they can be made to produce a great number of plants, but if cut in pieces as small as half an inch square, of course the yield will be proportionately small. They should be planted as soon as the ground will admit being worked".

Editor of the Horticulturist: - Your printer has given me a fair excuse for a farther note from the 8. West:

He makes me say that an orchard cannot be too "highly " cultivated and cropped".

To chime in with the context, as well as with my most devout and potent belief on the subject, the word should have been "lightly"

Thus, having a bit of suitable land, and desiring to raise, say, pears and potatoes, instead of mixing them half and half all over the land, I would plant all the pears on one plat, and all the potatoes on the other.

No plough has ever entered my orchard since it was planted, and I have yet to find a healthy peach tree, or I may say, a healthy fruit tree of any kind six years old, outside of my own enclosure. This is no boast, but a melancholy fact!

The land should not be "highly cultivated " in the common acceptation of these words; and it should not be cropped at all; but the surface should be kept clean, and the simple aliment required by fruit trees should be supplied.

Recent articles in the Horticulturist have induced me to make a thorough examination among the roots of my dwarf pears. I find them ever seeking the surface. If they were planted too deep, turning up; if planted properly, radiating horizontally, and spreading beyond my desire to trace them.

The great beauty and vigor of all the trees thus situated fairly countenance the experiment of an ingenious friend, who has grafted surface roots into his dilatory pears!

But, what is to become of this all-important furniture of a tree, under any system of earthwork known to a horse-hoe, it is easy to imagine; and as high cultivation and deep ploughing are nearly synonomous, we perhaps have the key to the sporadic success which has dotted the land with specimens of enormously large old pear trees.

Fruit, God's (next) best gift to man, has been most barbarously treated, and that it seems to be about taking its final departure from our earth (and markets) is, I think, as much to be attributed to "high cultivation" as anything else.

Skillful cultivation is another matter, and consists, according to my heresy:

1st, in the deepest possible preparation of a not exhausted or artificial soil.

2d, in the shallow planting of a young tree's roots.

3d, in the shallowest possible subsequent cultivation.

In my practice I avoid this latter item altogether*, wishing merely to keep the surface clean, the green grass is simply burned down by igniting the debris of a previous combustion.

There is always a thin brown mat of scorched grass on the ground; this covers no small amount of fine charcoal and ashes, our only manure; and thus waits its turn to level its suc-cessors.

Fire is of course a dangerous element, but thus harnessed it cannot injure the trees, while the roots are amply protected by an inch or so of that non-conducting material, the earth.

In short, I know of no surer way to get a good orchard than to devote the whole of the ground to it. Very respectfully, F. O. Ticknor.

Torch Hill, Columbus, Ga.. Feb. 5,1859. .

P.S. Do not let your "market" friends demonstrate that it is not worth while raising pears at all, for it is my pleasant delusion that one large Duchesne is cheap at the expense of planting one small tree.