another with half the quantity of such rubbish and at the bottom of some of the pots, I placed, by way of substratum, a layer of about four inches of strong yellow clay; to others a layer of four inches of chalk: having filled several pots with each of these preparations, I placed some of each of them under glass, in a conservatory; and others on a pavement in the open air. I also placed some pots in pans or dishes, and others on the bare ground. The next summer after planting, the difference in their growth was scarcely perceptible; but the spring following, a great difference appeared in the state of their health; those plants in the pots which were placed in pans or dishes, were much diseased, and particularly those which had a substratum of clay and chalk; at last, one half of the young branches of these were destroyed by the canker or livid mortification, and the blossom buds generally thrown off. One half of those pots containing the diseased plants I then removed out of the pans, and placed them on the surface of the earth; these the next year did not appear diseased, except those with the clay and chalk, which were but little benefited. I then turned those plants out of the pots, and removed the clay and chalk, and replacing them in the pots with the loam mixture only, kept them without pans, and they afterwards assumed a healthy and prolific appearance, and continued in such a state.

Those plants which grew in the mixture of one third brick rubbish, proved to be the most perfect

in every respect; thence I conclude, that stagnant water is the cause of this destructive disease, and is also opposed to fructification.

After a season or two, observing my trees to decline in their growth, I commenced a course of experiments for manuring or feeding them; and to ascertain the best means of doing this, without disturbing the roots or the soil; for this purpose I prepared decoctions of various dried vegetable substances, extracts of different dungs, sugar bakers' waste, &c., and the blood of animals.

From a variety of observations I was induced to believe, that the effect of food, being given at one season or time of the year, or period of growth of a plant, was very different to that which was produced when given at another; and that the different state of the food when administered, also produced different effects. Those trees which had been supplied with a libera quantity of the extract of dung during the winter, and early in the spring, opened their wood buds, and extended their leaves before the blossoms, which subsequently declined, and fell off; those to which a strong decoction of sugar bakers' waste was given, were injured, and many destroyed by the roots rotting. Some plants were fed or supplied with a quantity of blood without separation, broken and mixed with a little water; these, with some of those which had been supplied in the winter with strong solutions of dung, were in the following spring affected very much with the blotched or blistered leaf and shoots. As a more

perfect demonstration of these latter causes and effects, I suffered some of those trees which were diseased to grow the next year, without any additional supply of food, when they recovered their health. I also took others that were healthy, and treated them in the same manner as the former, and these became diseased like them.

Having from these and many other observations been led to believe, that dung or its extract, and blood, or other animal matters, when brought in contact with the roots of plants in a putrefactive or undecomposed state, obstructed both their health prolificacy; and knowing that blood, when suffered to remain undisturbed a short time, formed two distinct substances, the serous and the clotted, and that the serous was less likely to putrify, more divisible, and more readily diluted, and reduced to the required state of food for plants, I took a quantity of blood as it had been taken from animals, and suffered it to remain in a vessel for a day or two, until it was separated; I then poured off the serum, and diluting it with different portions of water, applied it as food, not only to my peach trees, &c., but to every description of plant I had growing, either in pots or out of them; and all those which were fed with a mixture of about one part of serum, to from three to six of water, by applying it in the usual manner and quantity as water, discovered a more immediate and improved appearance than I had ever seen by the application of any other substance whatever; but I found that

this mixture applied either too frequently, or in too large quantities, produced disease.

It being obvious that a state of great luxuriance or increase of growth in a tree, is seldom accompanied by prolificacy in seed or fruit; and also that a state of poverty or sterility of soil is unequal to the production of a crop of fruit, I was desirous of ascertaining some means of modifying those extremes; and the above observations having furnished me with a clue, I proceeded to arrange a course of experiments. Different trees were supplied with certain quantities of food or diluted serum at stated periods, which evidently produced different effects; those trees which were fed liberally in winter, or early spring, made a luxuriant growth, but threw off their fruit; such as were supplied at a more advanced period of the spring, produced a larger spread of leaf, and luxuriant midsummer shoots, which of course rather obstructed than improved the growth of either the immediate fruit, or the wood for fruiting the next season. Those which were supplied at Midsummer, were forced into a fresh expansion of shoots and leaves, which, at so late a period, retarded the ripening of the fruit and wood; other trees I supplied with food or serum about the middle of the period, between Midsummer and the fall of the leaf, or from the beginning of August to the middle of September; and I observed that this in no respect injured the immediate fruit, but had the effect of increasing and forwarding the growth of

the fruit buds, which were forming for the next year; and so much so, that the trees thus supplied came into bloom in the house at least a month earlier than others which were of the same sorts, and placed along side, but under different treatment as to feeding; and they sustained their fruit throughout, and ripened it at least a fortnight earlier.

The best mode and proportion of supplying this food to the peach and nectarine trees in pots, I found to be, to give about three pints in the year, mixed in the proportion of three parts of water and one of serum, divided and given at three different periods: that is to say, one pint at the end of August, one in the middle, and one at the end of September.

As I have in the former part of my work shown it to be demonstrative, that from the peculiar formation of the roots, and the general habits of plants, they cannot take in or apply their food, otherwise than in a state of solution, and that water is the only medium of supply, I need only further remark, that the peach tree requires a liberal supply of water; and that those in the house to which I gave, in the proportion of about one quart to each pot, every alternate day whilst in leaf, by pouring it entirely over the leaves and branches, I found to be the most healthy and prolific; and the evening after sunset appeared to be the best time for this operation.

A certain method of extirpating the aphis in a

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