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Soot.

Peat dust.

Potash waste.

Sugar bakers

waste.

Tanners bark.

Malt dust.

Rape cake.

poor return. Coarse ashes and cinders are better than those that are finely sifted.

4. Soot.

This is a very powerful manure on most soils; but least upon strong or wet clay. Twenty bushels an acre are the common quantity applied on green wheat or clover in the spring.

5. Peat Dust.

From its abounding in hidrogen this should operate as a strong manure. Commonly too it contains much iron. Having a great attraction for humidity, it is very advantageous on dry sandy soils. Mr. Farey asserts it to be the best possible dressing for onions.

6. Potash Waste.

The alkali having been extracted, this is not a powerful manure, but does good in low meadows, and on grass lands in general. Ten loads an acre, or 350 bushels, are a common quantity.

7. Sugar-bakers Waste. Some say this is a powerful manure.

8. Tanners Bark.

The tanning principle is probably in all cases hostile to vegetation. If this bark be ufeful any where, it should be on calcareous soils. Sometimes it appears to have diminished a crop of corn very considerably.

9. Malt Dust.

Eighty bushels an acre have exceeded dung on clay land for wheat. From twenty to forty bushels are commonly used, and with success on various soils.

10. Rape Cake.

About half a tun an acre is an excellent manure, but since the price has risen less is used. Mr. Coke, by drilling it in powder with turnip seed, makes a tun do for five or six acres.

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Of the fossil manures lime was included in the first division, and coal ashes were classed with those of wood and peat, so that only two remain.

1. Salt.

Little is known of this at present. In too large a quantity Salt it is injurious. It is certainly beneficial when properly applied. Perhaps it is best when mixed with dung or compost.

2. Gypsum.

Many persons assert, that this is no manure; others, that it is almost uniformly advantageous. It is said, to act as an immediate manure to grass, and afterward in an equal degree to grain: to continue in force for several succeeding crops to produce an increase of vegetation on stiff clay soil, but not sufficient to pay the expense: to be beneficial to flax on poor dry sandy land: to be particularly adapted to clover in all dry soils, or even on wet soils in a dry season: and to have no effect in the vicinity of the sea.

Of Composts.

These Mr. Young considers in the same light with dung- Composts. hills: he is of opinion, that the materials composing them would produce at least equal if not superior effect when applied to the land directly.

XV.

On the Formation of the Winter Leaf Bud, and of Leaves.
By Mrs. AGNES IBBETSON.

SIR,

To Mr. NICHOLSON.

YOUR obliging notice of my former papers has embol- Use of the bud

dened me, to trouble you again. There is no part of a plant not yet known, or tree more various in its formation, and in its consequences more astonishing, than the gemma, or bud. In spite

of

Method in which leaves are formed.

This apparent on dissecting very early buds.

of the abilities of a Malpighi, a Grew, and many others, its real use is not yet perhaps known. So defective were our magnifying glasses at that time, so impossible was it to reader an opake object luminous and ca, that we cannot wonder they did not attempt to search farther into the formation of the bud: for there is hardly any study, that requires the objeets being so much magnified, and opake specimens so clearly delineated. What follows I offer as the result of many years study; I offer it with the greatest diffidence, but with the most thorough conviction of its truth: nor have I trusted wholly to my own sight, many have seen the specimens on which I first founded my opinion, and drawn from them the same conclusions; which, though from their novelty they may surprise, will on farther examination in very young buds and leaves soon give conviction.

66

This opinion is, "That leaves are formed or woven by the "vessels or cotton, that is generally supposed by botanists placed there to defend the bud from the severities of "winter. That these vessels are a continuation of those "of the bark and inner bark in the stem of the plant, "That these vessels compose the various interlacing "branches of the leaf, which are soon filled up by the con"centrated and thickened juices of the inner bark, which "form the pabulum of the leaf,”

The truth of this assertion is easily seen by dissecting very early buds, where except two or three scales, nothing but these vessels will be found. What then could be the use of them?-to put them within the bud to keep the outside warm is against nature, for it is against reason. 1 shall begin with the anatomy of the bud from its first appearance; which will explain the whole process, as far as constant attention Buds of three could give me an insight into it. The gemma or bud grows on the extremity of the young branches. It is a small round or pointed body; and is fixed on the young shoot, and along the branches on a sort of bracket. There are three sorts. The leaf bud, the flower bud; and the leaf and flower bud. It is the leaf bud alone 1 mean here to dissect: for their natures are totally different, as are the purposes for which they are intended. As I look on the leaf bud to be formed

kinda.

almost

almost wholly of the bark and inner bark, so the flower bud is a composition of every part and juice of the tree.

The leaf bud is generally smaller than the other two; in The leaf bud. its first state it consists of two or three scales, enclosing a parcel of vessels, which have the appearance of a coarse kind of cotton, very moist; but when drawn out, and placed in the solar microscope, they show themselves to be merely the vessels of the bark and inner bark elongated and curling up in various forms. They are generally of three sorts, like the bark, &c, First three or four short thick ones that appear to grow from the larger vessels of the inner bark, and through which the thickened juice flows, but with this difference, that the holes are not there. Then there are two smaller sized vessels, that exactly resemble the smaller vessels of the bark. The former I have ever found to be the midrib of the leaves; the latter the interlacing of the sinaller vessels and I have so often taken a leaf and dissected it to compare it with the vessels which I the next winter found in the leaf bud of the same tree, that I cannot but feel the most thorough conviction, that I have in the bud traced its origin; though certainly much enlarged in the full grown leaf. The pabulum of the leaf, or that which lies between the vessels, is (as I have before said,) composed of that thick juice which runs in the bark or inner bark of the tree, and is to be found in no other part. It differs essentially from the sap, and may be called the blood of the tree, as it possesses its peculiar virtues, is gum in one, resin in another, oil in a third, according to the nature of the plant. Whether it flows both forward and retrograde I have not yet been able to discover; indeed, finding the subject in the hands of a gentleman of such abilities as Mr. Knight, I Mr. Knight. waited his decision: but that the greatest part is taken up in forming the leaves I feel the most perfect conviction. The pabulum of the leaf, after the vessels are arranged and crossed, grows over in bladders, making alternate layers with the smaller pipes, and with the branches of the leaf. But I have found, and shall give, many specimens before this part of the process is begun.

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I know not any tree that gives a more convincing proof Formation of of the manner of forming leaves in the bud than the borse the leaf of the

chestnut:

horsechestnut.

Mode of arranging the leaves in the bud.

chestnut but it should be taken in November or Decem ber. Several different midribs may be taken at once from the same leaf bud, with an innumerable number of silken vessels extremely fine, fastened, or growing up each side the midrib. When these have interlaced each other sufficiently, the pabulum will begin to grow over them, in small bladders full of a watery juice. The next process is the larger. vessels crossing over them, and then another row of bladders; this continuing till the leaf is at its proper thickness. The leaves thus formed are very small, but when once their shape is completed, they then continue growing all together.

A drawing will so much better explain this than any description, that I shall beg leave to refer to the sketch of the several specimens of beginning or half formed leaves taken out of the buds of, various trees.

When the leaves are so far completed, the rolling and folding begins. Each tree has its peculiar mode of arranging its leaves in the bud, as Linneus beautifully exemplifies, some double their leaves, and then roll them round one midrib; some round several, each of which has its own middle vessel; some plait, some fold the leaf. The variety is prodigious; but it must not be supposed, that once is sufficient to complete the process; I have had the most thorough conviction, that it is repeated several times, immersed all the while in the glutinous liquor, that runs in the bark, and forms the pabulum. During this arrangement, the pressure of the leaves is very great; and it is this and the rolling, that completes them; for if a leaf is taken from the bud, before this process, it will be like a piece of cloth before it is dressed; that is, with all the ends and knots to it; thus the back of the leaf will be obscured by the ends of vessels, which are at last all rubbed off, the hairs excepted, which remain to many plants.

Formation of The next process is the forming the edges of the leaves, the edge of the the most curious and the most beautiful of all. The bud, leaf. if opened, will appear full of that glutinous liquor, and the leaves folded according to the order to which they belong. Take out one of them, and the edges, folded as it is, will exhibit a perfect double row of bubbles following the scollop of the leaf's edge, and appearing as if set with brilliants,

I hardly

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