ground only a very short time; and the quality of both is excellent. I cannot, however, recommend either of them for the markets of the metropolis, where large size and yellowness, without regard to taste or consistence, constitute excellence, and wholly regulate the price of early Potatoes. The tubers of both varieties are below their ordinary size, on account of the almost incessant rain, and coldness of the weather, during the period in which they were growing, and the natural dampness of the soil in which they grew.

With the Potatoes, I send a few Spanish Chestnuts, the produce of a young tree that grows here. I have given an opinion in the Horticultural Transactions of 1808,* that this fruit might be cultivated by grafting, and by a proper selection of varieties, with very great advantage in this country; and Sir JOSEPH BANKS has subsequently favoured the Society with observations upon the proper culture of it. The situation in which I live is high, and very cold; and the Chestnut Trees are in consequence almost wholly barren, exclusive of a single tree, which in every moderately favourable season affords very fine fruit, little inferior in size to those imported from the Continent. Those you receive for the inspection of the Members of the Horticultural Society were not selected as the largest; for you will see by their forms, that three generally occupied a single capsule: nor are they in a greater state of perfection than usual, for the spring and early part of the summer, in this part of England, were exceedingly cold and wet; and the annual branches of the Chestnut Trees werę much injured by the severity of the frost in April. The produce of this tree, which I can scarcely suppose See page 140.

* See page 62.

the

best, or earliest, variety in the kingdom, is so great in the very unfavourable situation in which it stands, that I am satisfied that any given quantity of proper ground, planted with such trees, in the warmer parts of England, would support a much larger population, even though half their produce were employed in fattening hogs, than an equal extent of pasture. The tree, which I possess, is about thirty-five years old, and has obviously not been grafted.

I much wish it were in the power of the Society to establish a garden, in which the comparative merits of different varieties of this and other fruits, and of the Potatoe and other esculent plants, could be accurately proved and annually reported. The agriculture of France, under the old and present government, is supposed to have derived considerable advantages from an establishment of this kind, the Jardin des Plantes; and more than equal advantages might arise in this country, where the cultivators of the soil are generally much more enlightened, and always prepared to introduce, and profit by, improvements of every kind. If the most productive variety of the Potatoe alone, and those best calculated for different soils, and seasons of the year, could be dispersed over the island, that alone would prove of no inconsiderable national importance.

I remain, my dear Sir, &c.

THOMAS ANDREW KNIGHT.

Downton, November 28, 1811.

POSTSCRIPT.

Sir JOSEPH BANKS has recommended jars for preserving Chestnuts, of British growth, during winter; and I have tried that method with tolerable success. But I have subsequently found, that both Chestnuts and Walnuts may be preserved through the whole winter, nearly in the state they came from the trees, by covering them with earth, (as Potatoes are usualy covered in the gardens of cottagers), and mingling a sufficient quantity of moderately dry mould with the nuts, to occupy the spaces between them.

LI.

On the Abvantages of employing Vegetable Matter as Manure in a fresh State. By THOMAS ANDREW KNIGHT, Esq. F. R. S. &c. President

Read January 6, 1812.

WRITERS upon agriculture, both in ancient and modern

times, have dwelt much upon the advantages of collecting large quantities of vegetable matter to form manure; whilst scarcely any thing has been written upon the state of decomposition, in which decaying vegetable substances can be employed, most advantgeously, to afford food to living plants. Both the farmer and gardener, till lately, thought that such manures ought not to be deposited in the soil till putrefaction had nearly destroyed all organic texture; and this opinion is perhaps, still entertained by a majority of gardeners; it is, however, wholly unfounded. Carnivorous animals, it is well known, receive most nutriment from the flesh of other animals, when they obtain it most nearly in the state in which it exists as part of a living body; and the experiments, I shall proceed to state, afford evidence of considerable weight, that many vegetable substances are best calculated to re-assume an organic living state, when they are least changed and decomposed by putrefaction.

I had been engaged, in the year 1810, in some experiments, from which I hoped to obtain new varieties of the Plum; but only one of the blossoms, upon which I had operated, escaped the excessive severity of the frost in the

spring. The seed, which this afforded, having been preserved in mould during the winter, was, in March, placed in a small garden-pot, which was nearly filled with the living leaves and roots of grasses, mixed with a small quantity of earth; and this was sufficiently covered with a layer of mould, which contained the roots only of grasses, to prevent, in a great measure, the growth of the plants which were buried. The pot, which contained about one-sixteenth of a square foot of mould and living vegetable matter, was placed under glass, but without artificial heat, and the plant appeared above the soil in the end of April. It was three times, during the summer, removed into a larger pot, and each time supplied with the same matter to feed upon; and in the end of October its roots occupied about the space of one third of a square foot, its height above the surface of the mould being then nine feet seven inches.

In the beginning of June, a small piece of ground was planted with Potatoes of an early variety, and in some rows green Fern, and in others Nettles, were employed instead of other manure; and, subsequently, as the early Potatoes were taken up for use, their tops were buried in rows in the same manner, and Potatoes of the preceding year were placed upon them, and covered in the usual way. The days being then long, the ground warm, and the decomposing green leaves and stems affording abundant moisture, the plants acquired their full growth in an unusually short time, and afforded an abundant produce; and the remaining part of the summer proved more than sufficient to mature Potatoes of an early variety. The market gardener may, probably, employ the