There is no fruit tree cultivated, under glass of so much importance as the vine, nor any so useful for the dessert. Pine-apples, although expensive, owing to the amount of fuel which they require, are less esteemed by most persons. Peaches and nectarines are admirable and delicious when brought to perfection; but they are soon over, unless forced in successional houses. From one grape house, however, a long supply for the dessert may be daily obtained, with proper management and a judicious selection of sorts.

But it frequently happens that in houses of well established vines there are sorts for which it would be desirable to substitute others. A set of young vines, raised from eyes, if planted in a fresh made border will soon fill a house; but the rooting up of an established plant from amongst others, and planting a young one in its place, is in some respects an objectionable proceeding; for the roots of those intended to remain are liable to be injured, or otherwise they take possession of the newly loosened soil prepared for the young plant before the latter is itself able to do so. In order to avoid these inconveniences recourse should be had to grafting, which will be found the best mode of substituting for any existing sort one that is more desirable. As regards the vine, however, the principle of this operation is not, generally speaking, so perfectly well understood as it ought to be. It is very simple; but many failures, with considerable loss, and disappointment, have been the result of not knowing it. It consists in performing the operation when the vine is in active growth, and can be cut without bleeding.

If this is attended to, any of the usual modes of placing the scion is contact with the stock will succeed, such as whip, cleft, or saddle grafting; but a certain failure will be the result of every mode if performed when the vine is in a bleeding state.

Mr. Knight states in a paper read before the Horticultural Society, in 1821, that "The practice of grafting the vine appears to be very ancient; for it is mentioned both by Cato and Columella in a way which shows that it was common in the vineyards of Italy at the period in which they wrote. It must consequently have been an operation of easy execution though it is rarely seen to succeed well in the hands of the modern gardener, who is, nevertheless, certainly much better provided with instruments, and can scarcely be supposed to be inferior in skill or science to the cultivators of that period. It is therefore probable that the ancients were acquainted with some mode of operating, of which the modern gardener is ignorant. It is well known that the ancients in propagating the vine, employed cuttings which consisted partly of one-year-old and partly of two-year-old wood." Mr. Knight conceived it probable that the success of the Roman cultivators in grafting their vines might have arisen from the selection of grafts similar to their cuttings. He therefore selected scions consisting of about 2 inches of old wood and 5 inches of annual wood. With these he was successful; but the condition of the vine as. regards its vegetation is not stated.

It is, however, evident that if he had known the simple principle to which we have as above directed attention, he would have at once expressly and clearly pointed it out. Instead of ascribing his success to the circumstance of employing a portion of two-year-old wood, he could have stated that with scions of one-year-old wood the chances would be that not one in 20 would fail, especially in the hands of so practised an operator as Mr, Knight was known to be. This great physiologist, however, in 1832, pointed out the right principle in the analogous case of grafting the walnut-tree.

So far as we are aware the credit of first discovering and explaining the essential principle for the successful grafting of vines is due to the late John Braddick. In a communication from that gentleman to the Horticultural Society in 1822, and which was published in the "Transactions of the Society," details of experiments are given which render evident the cause of failure, and likewise the principle according to which success in vine grafting is ensured. Believing that many of our readers would profit by an account of these interesting and conclusive experiments, we give the following extract from Mr. B.'s communication.

"The information which I collected from books on that subject was, that Vines may be easily made to grow by grafting; and that the proper time f6r performing the operation was in January and February, for vines growing tinder glass; and in March for vines growing in the open border. But out of 40 or 50 vines which I operated upon in the; above months, I had the mortification to find that very few of the grafts grew, and those which did take became weakly plants.

"I observed that the stocks of the vines grafted as above mentioned all bled profusely, and upon unbinding those grafts which did not take, I found that the parts of the grafts which joined to the stocks were sodden and turned black, by their being steeped for a considerable time in the thin sap of the stock.

To stop the bleeding I tried every experiment with styptics, cements, etc., which I ever heard of, with many others suggested by my own imagination, but all without effect. One experiment I will mention, as it may serve to show the great power of the rising sap of the vine while its buds are breaking. On March 20, in the middle of a warm day, I selected a strong seedling vine five years old, which grew in a well-prepared soil against a south-west wall; I took off its head horizontally with a clean cut, and immediately observed the sap rising rapidly through all the pores of the wood from the centre to the bark. I wiped away the exuded moisture, and covered the wound with a piece of bladder, which I securely fastened with cement and a strong binding of waxed twine. The bladder, although first drawn very close to the top of the shoot, soon began to stretch and to rise like a ball over the wound; thus distended, and filled with the sap of the vine, it felt as hard as a cricket ball, and seemed to all appearance as if it would burst.