chises, and these again to the mulleins, campanulas, and various other plants, all in their turn delighting the eye, and gladdening the heart; nor is the winter season devoid of interest; the surface of the ground, and every decaying leaf and twig, are inhabited by a world of microscopic beauties. All these have maintained their ground without interfering with each other, year after year, and generation after generation. The same page in the great Book of Nature, which filled the mind of Ray with the wisdom of God in creation, lies open to our view. "All these things live for ever for all men, and they are all obedient. All things are double one against another, and He hath made nothing imperfect. One thing establisheth the good of another, and who shall be filled with beholding His glory?" Can man, with all his boasted wisdom, realize such a scene as I have just attempted to depict? He cannot; he would feel that, "when he hath done, then he beginneth, and when he leaveth off, then he shall be doubtful."

I have dwelt at some length on the natural conditions of plants, convinced of the paramount importance of a knowledge of these conditions to all cultivators of plants, and cannot do better than sum up in the words of a great philosopher of the present day.

"If the laws of Nature, on the one hand, are invincible opponents, on the other, they are irresistible auxiliaries; and it will not be amiss if we regard them in each of these characters, and consider the great importance of them to mankind:

:

Firstly. In showing us how to avoid attempting impossibilities.

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Secondly. In securing us from important mistakes in attempting what is in itself possible, by means either inadequate, or actually opposed to the ends in view.

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Thirdly. In enabling us to accomplish our ends in the easiest, shortest, most economical, and most effectual manner.

"Fourthly. In inducing us to attempt, and enabling us to accomplish objects, which, but for such knowledge, we should never have thought of undertaking."-HERSCHEL.

CHAPTER II.

ON THE CAUSES WHICH INTERFERE WITH THE NATURAL CONDITIONS OF PLANTS

IN LARGE TOWNS.

As well might corn as verse in cities grow;
In vain the thankless glebe we plough and sow:
Against th' unnatural soil in vain we strive;
'Tis not a ground in which these plants will thrive.

COWLEY.

LARGE TOWNS.

AMONG the causes tending to depress vegetation in large towns, mining districts, &c., may be enumerated, deficiency of light, and of moisture, the fuliginous matter with which the atmosphere is always more or less loaded, and the presence of noxious gases.

Enough has been said upon the all-important agency of light in the functions of the vegetable system, to convince us that we shall not err in