Sir: The sweet potato forms a very important article of provision on the southern plantations. It is so subject to rot - even by the 1st of January - that it is much less planted than would otherwise be the case. There are various modes adopted to preserve them, yet none giving entire assurance. It has struck me that some way might be adopted of kiln-drying them. This would reduce them greatly in bulk, by ridding them of water - the principal cause of their decay. They would thus be brought to a state easily convertible into a flour.

This notion first suggested itself to me in the famine year, when a good deal of Indian corn was kiln-dried to stand a voyage to Ireland.

I do not think I exaggerate, when I consider it a matter of national importance, an this ground beg that yon will turn it in your mind. Should you be at fault, a suggestion in your paper would bring out some of your correspondents upon the two points Is the scheme a practicable one? If so, what mode of preparation would best accomplish it?

I do not give my name - it would add nothing to the importance of the subject, nor ought it to do so.

I send this to your paper, as - taking it - I shall see anything you may say on the subject. Charleston, S. C, June 10, 1851.

We shall be glad to hear from correspondents who have information to communicate on this subject. Ed. --------Peach-Trees - The Effect of Shortening-™. - Last winter we tried the experiment of shortening-in the branches of a portion of a peach tree, and leaving the remainder untouched, in order more fully to test the beneficial effects of the practice, and give an occular demonstration of the difference, if any should appear, resulting from the operation, to all who might witness the result. The blossoms on the branches shortened-in. came out from a week to ten days earlier, and the fruit at the time of writing, is at least one-third larger than that on branches left in their natural state. The new growth of wood on the shortened branches is of a more vigorous and finer character, and will probably acquire a greater degree of hardiness, to enable it to withstand the vigor of the coming winter.

But this, too, is labor, and being so, it will be an objection with many to any further attempts to raise peaches. Yet it is a labor of pleasure, if not of profit., to all who wish to enjoy the satisfaction of seeing nature yielding to their control, and nature perfecting herself under their influence. To those who have pleasure of tasting rich fruit of their own raising, and plucking it in delicious freshness from the tree, it will be but a light service, compared with emptying their pockets to purchase the fruits of other climes, too often gathered in a crude and immature state, in order to enable them to survive transportation, and contracting insipidity and decay in every step of their journeying.

We might before have remarked, for the benefit of the inexperienced, (if any of your readers are more so than myself,) that in shortening we are sure to cut down to sound and vigorous wood, such as has not and will not winter-kill, and through which the sap will commence a healthy and vigorous growth in spring. Hence we take off rather more than the last growth of the season. If the work is delayed until February or March, we cut down to where the buds are healthful and strong. Y'rs truly, W. Bacon. Richmond, Mass., July 7, 1851.

A. J. Downing, Esq

Dear Sir: I should not venture to address you, but for two encouragements, (very faint ones to me, to be sure, but still encouragements,) which I find in the pages of the Horticulturist. One of these is your promise to answer all questions of your subscribers, if put in a brief form. Alas for me then! but - I have a question to ask. The other is your invitation to "Horticulturists and Amateurs to contribute Essays, Papers, or Rough Notes of Experience." Now, I am too ignorant for a horticulturist, but if amateur means a lover of flowers, (roses especially) I am one, most certainly; and I must detail my experience, in order to ask my question.

Two years since, I came in possession of four roses; the Fellenberg. Louis Philippe, Queen of Naples, and Gloire de France. These I planted out on the north side of the house, in the only place which could then be spared for them. I was instructed to cut them all down to within a short distance of the ground, on the approach of cold weather, but they grew so beautifully during the summer, that when autumn came I could not bear the thought of cutting them down. I therefore, took up the Fellenberg, and covered the rest carefully with straw, and placed a box over them. When I uncovered them in the spring, I found that the Queen of Naples and Louis Phillippe had each sent a shoot from the root, some six inches in length, which, for want of air, had died and moulded. These were covered too early, and with too much straw; so I had learned something from experience. On close examination, house, and added to them the Souvenir de Malmaison, White Monthly Moss Rose, (I have my doubts about its being a monthly,)Chroma-tella, and Gloire de Rosamene. The Louis Phillippe grew a few inches, then a careless boy snapped the top off with his whip-lash, and it never came up again.

The Gloire de France gradually died down to the root, then sent up one small sickly sprout, which grew an inch, and then stopped. I dug away the earth from the roots, and filled in with chip dirt, watering it plentifully, and it soon began to grow. The Souvenir de Malmaison was killed about as soon as I had it, by a great black bug, which gnawed into the heart of the root. I resolved to cover the roots with tan-bark this winter, but as they make no more scruple of disappointing ladies in the west, (this part of it, at least,) than others, my tan-bark did not come to hand; so I twisted straw carefully about the the stems, and about the middle of our very mild winter, all except the Moss Rose were covered with boxes, so placed as to admit plenty of air. This spring I found my Moss Rose entirely uninjured. - my two Glories, (of France and Rosamene,) at once sent up strong shoots from the roots; but my Chromatella - no, that too, is alive! A very small tuft of leaves made their appearance three inches up the stem. But in a very few days, to my dismay, these leaves began to droop. In my alarm I took it up, (breaking several long strong roots in the operation,) but could discover nothing which should cause its death.

A foot from where it stood, and within two inches of my Moss Rose, a very small something made its appearance when the leaves first began to droop, and growing with amazing rapidity, soon showed unmis-table proofs of its origin. I had not, then, lost my Chromatella. It is now seven feet high, and still growing at the rate of an inch a day. Now, Mr. Downing, mutt I cut down this splendid plant? Is there no way to save it? It has not blossomed yet, and I fear it will not this year. And my others, too, growing and blossoming beautifully as they are, must they against the winter severity upon her roses, and for that purpose, must state the following.

Two things are very essential to enable a half hardy plant to stand the winter. The first is, that there shall be no sappy immature wood, and the second, that the entire plant, (root especially,) shall be kept dry in winter. To secure the first, the ends of the long shoots should be pinched off, to stop their further growth, about the middle of September. This will cause the shoots to harden and ripen. To secure the second point, the border or bed should have a good drainage - either natural or artificial. Afterwards, at the approach of winter, our correspondent will strip off any leaves remaining on the shoots of the rose, bind down the long branches, and cover the whole plant, including them, entirely over with dry tan-bark - say to the depth of a foot and a half above the surface of the ground if necessary, and finally lay boards over the hillock of tan in such a way as to shed all the storms of winter, we think she will find her roses quite uninjured when she uncovers them in the spring.