Necessity and Use of Air.

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more easily float as well as fly in the air. Plants also require air to forward their growth and vegetation; hence they are provided with numerous vessels for its reception and transmission.

Nothing is more easy than to enumerate proofs of the necessity and use of air; we shall at present con. fine our attention to one only, which will sufficiently illustrate our assertion. If air did not exist, there would be no twilight before sun-rise; the sun would suddenly flame above the horizon bright as it noon-day; its aspect would not be changed till the moment in which it disappeared to leave us in total darkness. It is true, the sun would strike us with a most vivid light though there was no air, but it would resemble a fire in blazing during the night in an open country; it would some sense be day, whilst the sun and the objects which immediately surround us were vissible, but all the rays which fell on bodies placed at a certain distance would be reflected in a right line, and lost in the extent of the heavens. Thus, though the sun was placed immediately over our heads, we might yet experience a sort of night, if the atmosphere did not intervene between us and the luminary.

To recapitulate then all the advantages which the air produces to our globe: it preserves life, as being the principle of respiration to living creatures; through its medium winged animals fly, and those which inhabit the waters are enabled to swim; it serves for the propagation of sound, and conduces to the formation of vapours, rain, and wind; it is es sential to the fertilisation of the earth, favours the vegetation of plants, and by its agitation disperses the noxious vapours which exhale from different bodies. If air did not surround our globe, the light and heat of the sun would be insufficient for our purposes; sounds could not be transmitted, consequently onr organs of speech would be useless: in short, the

advantages which the air produces to the human race are without number; and if we accustomed ourselves to contemplate with an attentive mind this great agent of nature, we should be more and more led to exalt the works and the glory of God. If any have hitherto neglected this pleasing duty by having taken only a superficial view of the creation, and whilst they enjoyed the blessings of nature their hearts have not bowed before the presence of God, I beseech them, as they value their own happiness and wellbeing, to endeavour in future to become attentive spectators and observers of the works of God: for they who consider them with attention, and investigate them with ardour, are rewarded with a pleasure pure and unceasing: the study of nature is a source of everlasting joy, the springs of which never fail.

APRIL X.

Diversity of Soil.

THE Soil of the earth is not the same in all places; the upper bed is generally formed of a black, friable, and rich earth, which being mixed with the remains of plants and animal matter, becomes the nourishing parent of the many thousands of vegetables which enrich our globe. This bed often varies in quality; at one place it is light and sandy, at another clayey and heavy; sometimes it is moist, sometimes dry; here warm, and there cold. Hence we find that plants and herbs, which in some countries grow spontaneously, in others will not succeed without art and cultiva tion; and this diversity of soil is also frequently the cuuse why vegetables of the same species differ amongst themselves, according to the nature of the soil in which they grow. In this the wisdom of the Crea

tor is conspicuous: if all soils were alike, and pos sessed the same qualities and constituent parts, we should be deprived of many thousands of vegetables, as each species of plants requires a soil analogous to its nature. Some require a soil which is dry, others one that is moist; to some warmth is necessary, and to others cold; some flourish better in the shade, whilst others only expand in the sun; some again thrive on mountains, whilst the greater number prefer the valleys. Hence it happens that every country has a certain number of plants peculiar to it, and which do not thrive so well in others. If the elder is transplanted into a sandy soil, and the willow into one which is dry and rich, it will be found that neither will succeed so well in a soil different from that to which it has been accustomed. Thus nature provides for each that soil which is best adapted for its culture, each species growing in the soil most analogous to its con stitution. It is true that art often forces nature to produce according to our wishes; but the effects of this opposition do not always repay our trouble and expence, and nature, in the end, is found superior to all the researches of skill and operations of art.

As the soil is infinitely varied, so also is the cha racter and disposition of men. There are some whose hearts are too insensible to profit by instruction, whom no motive affects, whom no truth, however forcible and evident, awakens from their stupidity. Such a character may be compared to a stony soil, which alike resists the temperature of the air and the assiduity of culture; a character little superior is that where continual levity predominates. People of this class may receive the salutary impressions of religion and piety; but, if the least obstacle impedes, they are discouraged, and their zeal vanishes as quick as their good resolutions. Such as these are those timid and frivolous people who reject truth because they are afraid to receive it, and in whom piety cannot take

root because there is no depth; they resemble the light and dry soils where nothing arrives at maturity, where the scorching heat of the sun dries up every thing, because the soil does not afford the succulent juices necessary to the nourishment of the plants. Happy are they in whom, as in a rich soil, the seeds of virtue mature into an abundant harvest of choice fruits!

On this diversity of disposition, among men, depends more or less the effect which the sacred word produces in their hearts. In vain may the sower sow the best seed, and useless will be his care, if the soil which receives it has not the requisite qualities: the excellence of the seed can never alter the sterility of the soil; which, if so hard and unyielding that the seed cannot enter, or so sandy that it cannot take root, or so stony as to choak it up, will never bring forth good fruit. To whichever class we may belong, whether the impenetrable hardness of our hearts resists every impulse, or the frivolity of our disposition admits of no steady pursuit, we shall readily acknowledge that before the seeds of truth and of virtue can ripen into maturity and produce fruit, before we can attain the enjoyment of felicity and blessed peace, our hearts must be changed. To effect which must be the work of the holy spirit; and may the Almighty in his condescension assist us, and enable us to become like the fruitful soil, and, faithful to our vocation, bring forth abundance of fruit, that, rich in good works, we may preserve the gift of his grace in a good and generous heart.

APRIL XI.

Necessity of Repose during the Night.

LABOUR is useful and necessary to man; upon it depends much of the happiness and convenience of life,

Necessity of Repose during Night.

-193 and every one, according to his state and condition, should apply himself to it. But by incessant exertion human strength would be speedily exhausted, and man would become incapable of using his bodily powers, or of exerting the faculties of his mind, if nature did not, by continually supplying him with this new vigour and activity, enable him to fulfil the duties of his vocation. As we daily lose a portion of our nutritious juices, we should soon become exhausted, and suffer a fatal consumption, was not our vitality con tinually renewed. This is supposed to be effected, and the ability to labour supported, by a matter inconceivably tenuid and penetrating, secreted from the blood and called the nervous fluid, which supports the action of the brain and muscles. But the continual dissipation of this fluid would soon exhaust it, and man would become languid and enfeebled, unless the waste was continually repaired.* If the body was kept constantly in a state of action, our aliment could not be digested, nor its nutriment be regularly distributed to every part.

It is necessary then that the labour of the head, as well as the exertion of the body, be for a time suspended, that our wearied nature may regain strength and vigour. Sleep renders us this important service: as night approaches, the powers which have been exerted during the day diminish, our vitality seems to be weakened, and we are irresistibly urged to sleep; during which state, when the activity of thought and the labour of our hands have ceased, our fatigued body acquires new force and fresh vigour. This renovation is as necessary to the body as to the mind;

* Whatever is the cause of that excitement which stimulates to action, or of the renovation of exhausted strength, the nervous fluid so much talked of has never been discovered; we merely know that the nerves are essential to sensation and life.-E. VOL. I.