nected with the varied phenomena of the Four Seasons, and with one exception, to be reserved for minute consideration hereafter; all substances enlarge in bulk when heated, and contract when cooled.

These temporary expansions by heat, and contractions by cold, are but small in the generality of closelycompacted solids, great in mobile liquids, and greatest in attenuated gases and vapours.

Some substances, especially the metals and their ores, have the power of conducting heat with great facility throughout their entire mass, so that it matters not where heat be applied, they will in due time be equally elevated in temperature.

Other substances, especially the earths, and their compounds, generally absorb heat rapidly upon their surfaces, and only conduct it very slowly and imperfectly throughout their mass, therefore heat chiefly remains upon the part to which it is originally applied.

Lastly, some substances, especially air and water, will not admit of being heated by conduction.

The chemist accordingly classes the foregoing substances, as conductors, imperfect conductors, and nonconductors of heat; and he has reason to admire and appreciate the beneficial results that ensue from their several habitudes with this agent. The transparent atmosphere is so wonderfully constituted, as to allow the rays of the sun to pass through it, without absorbing their heat; but upon reaching the opaque surface of the solid earth, it immediately absorbs heat, and

becomes elevated in temperature; then the air incumbent upon it obtains heat by contact, and is thus rendered lighter, volume for volume, than it was; it rises, and its place is immediately occupied by another and colder stratum of air; this becomes heated, and lighter, and in its turn rises, whilst colder air falls, and thus by ascending and descending, or convective currents, the atmosphere becomes heated from the earth, and not by direct conduction from the sun.

Thus winds are produced by the continued motion of cold air to supply the place of that which ascends in a heated state.

Transparent water is heated by the warm air that blows over its surface, and not by direct conduction of heat from the sun; but these matters will be particularly explained in their proper season: it may, how ever, be remarked, that if earth, air, and water, were conductors of heat, the animated creation could not exist; the sun would immediately heat the earth intensely, the water would wholly disappear; the air, instead of being a temperate mantle, would become a scorching shroud, or, in the more emphatic language of Scripture," the heaven would be as iron, and the earth as brass."

Electricity is the third imponderable element of whose ultimate nature the chemist is entirely ignorant, but he has every reason to suppose that it is universally present with light and heat; it is not manifest to the senses unless its equilibrium be disturbed either naturally or artificially, and then in the former case its

mysterious power is displayed as flashing lightning, and in the latter as snapping sparks.

The chemist can control electricity to a certain extent, for he discovers, as in the case of heat, that some substances have the power of conducting, others of retarding it, or of arresting its passage.

Air is a non-conductor, water and earth are conductors of electricity; and when it has accumulated in clouds to a certain degree of intensity, the flash of lightning announces its escape by rending asunder the non-conducting air to meet the conducting media of the waters and the earth.

Such is a general introductory statement regarding the elements of natural productions, and the agents unto which they are subject; we may now proceed to examine the Principal Chemical Phenomena of the Four Seasons; and throughout them all, we shall be presented with proofs of the Power and Goodness of God, "who hath created these things, that bringeth out their host by number; He calleth them all by names by the greatness of His might, for that He is strong in Power; not one faileth."

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CHAPTER I.

SPRING.

How beautiful is the Creation! how full of harmony, order, and proofs of the power and goodness of God!

Abundantly as these are presented throughout the Four Seasons, they are never more obvious than in Spring, when verdure clothes the earth, as the snow of Winter vanishes under the genial influence of solar heat. All things rise in praise of the Creator, and He beneficently ordains them to be as salutary to our bodies, as they are delightful to our senses: our fervent emotions of gratitude are called forth by this wondrous change of season; and if we cultivate an acquaintance with its glad attributes, and humbly endeavour to interpret the unerring laws by which they are governed, we gain a valuable fund of knowledge, which is calculated to make us not only wiser, but better, as it leads us to the highest appreciation of the miraculous workings of Providence.

The germination of seeds, and the growth of plants, present "the servant and interpreter of nature" with

several phenomena which admit of elucidation through the science of Experimental Chemistry, and accordingly these will first claim our attention; it will next be directed to an examination of the manner in which the earth receives and retains water, for the welfare and support of vegetation; and having ascertained this point, we shall proceed to examine the conditions under which water accumulates in the atmosphere, to form the showers of Spring, and its fertilizing agency even when it does not so descend upon the earth; the action of heat and cold upon the atmosphere will then claim our notice, and the changes which it sustains by respiration, germination, and combustion; we shall then pass on to examine some of the habitudes of the earth, in retaining heat, and the beneficial results which ensue from these; lastly, resuming the examination of vegetable growth, a few of the peculiar functions of plants will occupy our attention, as preparatory to others which will present themselves in the ensuing season of Summer.

First, as regards the Chemical phenomena, attendant upon the germination of seeds, and the growth of plants.

If we examine a seed, and for our general purpose no better can be selected than a garden bean, we find that its external membrane, or covering, is easily removed, and then it may be divided into two distinct portions, which are called Cotyledons; these enclose the germ, or embryo, whose largest part, or that most embedded in the Cotyledons, is called the plumula,