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at the point of junction, which may be seen in most old orchards. And if any number of grafts of different sorts be placed one above another, each will retain its proportion of Sap, and appropriate the same to its own peculiar nature.

If the Sap is passed through the body of the Tree to its leaves, and there prepared and returned back, that part which is uppermost, and producing one variety of wood and fruit, must possess the power of preparing the fluids, for the production of every other sort below it, unless the Sap be supposed to pass up, and return in the same state, which amounts to a superfluity of motion, and an excess of exertion, seldom found in nature.

This subject has always been one of controversy; but notwithstanding the great variety of ingenious and elaborate experiments that have been made, none seem to have been sufficiently conclusive, to produce unanimity of opinion. The subtle and prolix arguments that have been adduced on both sides of the question, have not only failed to contribute much to the benefit of the practical gardener, but the principle, as explained by Mr. Knight, must operate as an obstacle to knowledge, and a bar to perfect practice, which will be seen by a reference to the description of his own method of training; and also by the manner they have been acted upon by Mr. Maher, and explained by the secretary of the Horticultural Society, hereinafter noticed; and also by Sir Humphrey Davy. As to many of Mr. Knight's experiments, I agree with

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Mrs. Ibbotson, they may have been conducted with ingenuity and accuracy, but the results, as explained by him, cannot be generally conclusive.

To show the powers of Nature in continuing her functions, even after th e apparently complete destruction of her apparatus or systematic arrangement, I state the following facts. A person* having a green bergamot pear tree, that seldom produced any fruit, removed the bark three-fourths of the circumference, which was about twenty-seven inches, and the width of half an inch. A neighbour, for a joke, removed the remaining fourth part of the bark in the same manner, so that a circle of bark, of half an inch, was removed completely round the trunk : the tree, in consequence, was expected to die; but, to the astonishment of many who examined it, the tree lived, and produced fruit, and is now alive, although the operation was performed five or six years since. Supposing that in this case the bark had not been completely severed, and that a small part might have escaped observation, I made the experiment accurately, by removing the bark, quite round the branch of a pear tree, and with it the last annual layer of wood; a shoot was thrown out above the incision, which produced and ripened a pear, before the bark had formed a junction, which it did not accomplish until the third year.

* Mr. William Whitmarsh, of Wilton, in Wiltshire.

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The office and use of the Leaves of Plants are
nearly connected with that of the sap, and has also
been a subject of much intricate argument, but,
like that, discussed with very little practical effect;
and as it is an object of much more importance
than is generally considered by gardeners, I shall,
as before, give the opinions of the several authors

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upon it.

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1

Miller, speaking of the peach tree, says, “In
pruning of those trees, you should always observe
to cut them behind a wood bud, (which may easily
be distinguished from the blossom buds, that are
shorter, rounder, and more turgid than the wood
buds,) for if the shoot have not a leading bud
where it is cut, it is certain to die down to the next
leading bud, so that what fruit may be produced
above that will come to nothing, there being always
a necessity of a leading bud to attract the nourish-
ment; for it is not sufficient that they have a leaf

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bud, as some have imagined, since that will attract but a small quantity of nourishment. The great use of the leaves being to perspire away such crude juices as are unfit to enter the fruit." In another part, after giving directions for prun

says, “When these rules are duly executed, there will be no occasion to pull off the leaves of trees to admit the sun to the fruit, which is too often practised; for if we consider that the leaves are absolutely necessary to cherish the blossom buds, -which are always formed at the foot-stalks of the leaves, so by pulling them off before they have performed the office assigned them by Nature, is doing great injury to the trees, therefore I caution every one against this practice."

This author also says, “ The Rev. Mr. Hales, in his excellent treatise of Vegetable Statics, speaking of the perspiration of Plants, gives an account of the following experiment; viz.

“ That in July and August he cut off several branches of apple trees, cherry trees, pear trees, and apricot trees, two of a sort ; they were of several sizes, from two to six inches long, with proportional lateral branches, and the transverse cut of the largest part of the stems was about an inch in diameter,

“ That he stripped off the leaves of one bough of each sort, and then set the stems in several glasses, pouring in known quantities of water.

“ The boughs with leaves on them imbibed, some fifteen, some twenty, twenty-five, or thirty ounces,

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creased very

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in twenty hours, day, more or less, in proportion to the quantity of leaves they had; and when he weighed them at night, they were lighter than in the morning

" While those without leaves imbibed but one
ounce, and were heavier in the evening than in the
morning, they having perspired little.
The quantity imbibed by those with leaves de-

much
every day; the

sap

vessels being probably shrunk at the tranverse cut, and too much saturated with water to let any more pass, so that usually in three or four days the leaves faded and withered much.

He adds, that he repeated the same experiments with elm branches, oak, ozier, willow, sallow, ashen, currant, gooseberry, &c.; but none of these imbibed so much as the foregoing, and several sorts of evergreens very much less.

«. He adds also another experiment: on the 15th of August he cut off a large pippin with two inches of stem, and its twelve adjoining leaves ; that he set the stem in a little phial of water, and marked the quantity it imbibed and perspired in three days.

66 And that at the same time he cut off from the same tree another bearing twig of the same length, with twelve leaves, no apples on it, and marked the quantity it imbibed in the same three days.

“ That about the same time he set in a phial of water a short stem of the same tree, with two large

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