at mid-day lower when the sun is obscured than when in full action; but this may arise from his limited powers: his stoves being heated by fire flues, it is impossible to raise the temperature so high, and in an equal degree, throughout the house during the sun's absence, as when in its full refulgence; and his glass being air tight to keep in the heat, a change or circulation of air cannot be kept up without the consequences of a sudden depression or chill.

The arrangement that I am about to recommend has not, that I am aware of, been put in practice for the cultivation of the pine apple; and it may be objected, that theory, unsupported by practice, is of little value, but at the same time it may, with equal justice, be remarked, that practice, however successful, without the scientific principles upon which it may be understood, can be but of little value to any but the practitioner himself, as a correct knowledge of it cannot be communicated. It has been very justly observed by an eminent author, "Every thing which is wrought with certainty is wrought upon some principle; if it is not, it cannot be repeated." Unless the pine apple be exempt from the operation of those laws of nature which determine the growth and produce of all other plants, we may with propriety be guided by ana logy in forming a judgment as to the principles of its cultivation. Four years since, availing myself of Mr. Hague's patent steam apparatus, I erected it in a small house for the purpose of making some experiments in the growing of grapes, and of

peaches and nectarines in pots; and the production of healthy and prolific plants, and fruit of the most perfect colour, flavour, and general good qualities, being more an object with me than premature forcing, I determined on conforming to the course of nature more precisely, and particularly in the most favoured seasons, than has been usual in forcing houses; and it appearing to me, that the sun being obscured for several days following, attended by cold air during a particular period of fructification, has been the great and frequent cause of the falling off of whole crops of fruit, and constitutes what is vulgarly called blight; in the growing of peaches and nectarines, and of grapes, my endeavours have been to keep the temperature at mid-day, during cloudy weather, as high as at this period in full sunshine, which was from 80 to 100 degrees Fahrenheit, and upwards; and of suffering it to decline at night in the like proportion, as the natural atmospheric heat, which was generally so low as 40 degrees; and believing that the want of a due supply of air, as well as too high a temperature at night, was a frequent cause of the failure of impregnation in the blossoms, and also of the premature and unhealthy growth of plants into tall, long, and weak shoots and leaf-stalks, and of the insipidity and imperfect ripening of fruits, I introduced a constant flow or current of fresh air into the house, rarefied to such a degree (say from 100 to 150 degrees Fahrenheit) that in its diffusion it did not lower the general temperature, and the

result perfectly answered my expectations, almost every blossom set for fruit. The trees which were planted in pots ripened from two to four dozens of peaches or nectarines each, and they were as beautiful in colour, and pungent and perfect in flavour, as any produced in the open air; and the trees and plants were as close, stout, and luxuriant in the colour and growth of their leaves, stalks, and branches, as any that had grown without the house. The grape vine was equally benefited both in its growth and fruit; and I am very much inclined to believe, that to the same causes may be ascribed the extraordinary produce of the pine apple, which Mr. Knight describes as follows:

"In the month of June I gave a couple of pine plants which had shown fruit at six months old, and were of small size and of no value, to a child of one of my friends, to be placed in a conservatory in which no fires were kept during the summer; in the second week of October one of the pine apples became ripe, having previously swoln to a most extraordinary size, comparatively with the size of the plant; and upon measuring accurately the comparative width of the stem, and of the fruit, I found the fruit to exceed that of the stem as seven and three-quarters to one. The taste and flavour of this fruit were excellent, and the appearance of the other, which is not yet ripe, and is of a larger size, is still more promising."

The practice of transplanting the pine apple appears to be very common, but this, like the

application of bottom heat by fermentation, seems to be more the result of necessity, or economy, than the pursuit of any natural principle. Planting in pots certainly affords a ready means of ascertaining the extent, and of counteracting and checking injuries done to the roots, by exposure to the effect of fermenting heat; and that the roots of the pine apple under the common treatment are often partially, and sometimes wholly destroyed, seems pretty certain; indeed one of the oldest and, perhaps, most successful growers of the pine apple for the London market (Mr. Andrews of Vauxhall) declared to me his opinion that the pine-apple plant changed or threw off its roots annually; he also expressed his belief (to use his own words) "that it was oftener destroyed by fever than ague."

Agreeing with Mr. Knight, that the transplanting of fruit trees, although it brings them earlier into a fruiting state, occasions their next year's fruit to be smaller and less perfect, I also conclude it must affect the pine apple in the same manner. When the roots of all other plants have room for a free expansion, in a soil and on a subsoil perfectly adapted and congenial to their nature, they in all cases are found to be more prolific and exuberant in their produce; and why not the pine apple?

Among the growers of this fruit there seems to be no settled opinion, as to the composition of the soil it is planted in, or the best manure or food, or the proper times or seasons for dressing or feeding, nor indeed does there appear to be existing any re

gular system of management; but as it cannot be doubted that the pine apple, like all other fruits, must depend on these things, at least for its better qualities, I shall offer some observations on this part of the subject.

As I have elsewhere explained, it is the law of nature, that a plant shall attain a surface of stalk, branches, and leaves, proportionate to the food consumed or taken up by its roots, before it can attain a perfect fruitful state; thus it is found that a luxuriant supply of food produces a luxuriant plant, and a strong healthy plant produces large full fruit; but a luxuriant plant requires a longer time and larger space to extend itself in leaves and branches, before it becomes in a condition to fructify, than a stinted one. Reducing the channels of supply, or roots, is tantamount to curtailing the supply of food; and lessening the proportion of food, is the same in effect as extending the surface of the plant. On these principles, the effect of the general practice of transplanting, and curtailing the roots of the pine apple, may be accounted for; but although such operations are in general found to facilitate the fruiting of plants, they are unnatural, and must obstruct and prevent the attainment of perfection.

On transplanting and curtailing the root of the pine apple, a fresh soil and supplies of manure are generally given, with a view to prevent a loss of size and strength; but this again stimulates the plant to an increase of stalk and leaf, before it