MAY VI

Vision.

To enable us to perceive external objects, it is requisite that rays of light be reflected from them. These rays are transmitted to the eye, passing through the transparent cornea, by whose convexity they are united into a focus, through the aqueous humour and pupil of the eye, into the chrystalline lens, which con. denses them more; and after this concentration, they penetrate the vitreous humour, and impress on the retina the images of external objects; and the optic nerves, of which the retina is an expansion, convey these impressions to the mind, which forms perceptions and ideas according to the different sensations excited by the object presented.

The faculty of vision is one of the most wonderful properties of human nature, and particularly merits our attention, Though the image of external objects is painted upon the retina in an inverted position, we yet see them in their proper situation. And what is still more admirable with such a small organ as the eye, we perceive the largest objects, and take in the whole of their dimensions. From the height of a tower we see at a distance the numerous buildings of a large city painted upon our retina with the utmost exactness and precision, notwithstanding the extreme minuteness of the organ which receives so many millions of rays without confusion. From the top-mast we see the ocean covered with a vast fleet, and waves innumerable undulating around us; from each of which, rays of light must penetrate the eye, whose volume is so minute. Or, having gained the summit of some lofty mountain, if we direct our view over the distant plains, every object that we notice reflects a

Spring renews the Face of the Earth.

245 number of rays upon our organs of vision, or we could not distinguish the purling brooks, nor the flowery meads. Rays of light not only pass from these objects to our eyes, they are transmitted to every part of the surrounding atmosphere; hence, wherever we pass within a certain distance, the same objects are still visible, the rays constantly proceeding from them, whether they meet the focus of our eye or not.

So far we are able to explain the wonders of vision, but beyond this all is darkness; it has pleased the Almighty Creator to conceal from our limited understanding the immediate connection between matter and mind! we know the image of external objects is' reflected on the retina, and that the mind takes cognisance of it, and here we must rest satisfied; for to explain the manner in which we see these objects is impossible.

MAY VII.

Spring renews the Face of the Earth.

How great a change has taken place throughout na. ture! The earth, which has reposed during the win. ter, resumes its fertility, and all the creation rejoices! A few weeks since, every thing was desolate, and wore the aspect of sterility; the valleys now so beauti ful were buried in snow, and the mountains, whosc blue summits pierce the clouds, were shrouded in thick mist. In those verdant avenues where now dwells the nightingale, were only seen withered branches and leafless trunks. The rivers and streams which now flow murmuring along their channels, were ar. rested in their course, and rendered motionless by ice. The little choristers, whose loud notes swell upon the breeze, were torpid in their retreats, or had retired to

other climes. A mournful silence resigned in the fields, the groves were still, and as far as the eye could reach, solitude met the aching view. But when the first zephyrs of spring played upon the earth, nature felt their refreshing influence, and arose from her stupor; joy and gaiety were awakened, and laughing pleasure banished every care.

The sun-beams penetrate, the sweet flowers spring up, the trees again look young, the budding beauties and the freshness of the verdure gladden the heart, and its joy is perfected in feeling the happiness of all around. Who can behold such a picture without emotion, or see it without thinking of the ineffable Being that produced it? The Lord breathes upon the earth, and the valleys smile; he watereth them with his dew, and they are fertile. His presence ripeneth the harvests, and fills our hearts with joy. His blessing is upon the furrows, and the parching earth drinks of the refreshing rain which softens it, and the seeds spring forth. The year is crowned with blessings, and the breath of God maketh the ground fruitful; under his steps flowers and fruits spring up, and all fruitfulness and abundance belong unto him. The pastures are watered with soft showers, and the hills are adorned with a beautiful verdure. The fields are covered with flocks, and the young corn rejoices the valleys. All nature rises in one general song of praise and thanksgiving to her bountiful Parent.

In the revolution effected by the mild influence of the spring, I seem to see the representation of that salutary change which the soul feels when it yields to the operations of the divine spirit of God. Before this it had no real beauty; its faculties perverted and depraved, were incapable of producing the precious fruits of piety, till the saving grace of God was felt in the heart, when it resembled the earth cheered by the vernal sun. Ignorance disappeared, the passions

Germination of Seeds.

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were controlled, and vice shrunk back ashamed: the heart glowed with virtue, and the mind was impressed with humility, and a firm reliance upon the blessed doctrines of truth.

MAY VIII.

Germination of Seeds.

MANY changes in the vegetable kingdom are now taking place under our immediate notice, whilst others are operating in secret, concealed from our observa. tion. The grain which had been previously deposited in the earth swells, and the plant at length sprouts and gradually shoots up. As this is the beginning of all the beauties which spring and summer offer us in the vegetable kingdom, it merits some attention. Seeds are composed of different parts, according to the variety of species, the principal of which parts is the germ. Each germ has two parts; the one simple, which becomes the root, and the other laminated, which becomes the stem of the plant. The substance of most seeds is composed of two pieces called lobes, which contain a farinaceous matter, and serve as seminal leaves to the plants, Mosses have the most simple seed, consisting only of the germ, without pellicle and without lobes. To make seeds germinate, air and a certain degree of heat and moisture are ne cessary. The augmented heat, and the difference observable in the taste and smell, seem to denote a de. gree of fermentation; and farinaceous substance be. comes fitted to nourish the tender germ. It has been ascertained by experiments made with coloured fluids, that this substance imbibes a moisture, which, in conjunction with the air and heat, forms a proper nourishment till the plant has required strength enough

to make use of the juices furnished by the root. The lobes, exhausted of their farinaceous matter, gradually dry, and fall off of themselves in a few weeks, when the plant has no further need of their assistance.

Certain herbs which grow on the mountains are of a particular nature; their duration being very short, it often happens that the seed has not time to ripen; and that the species may not be lost, the bud which contains the germ is formed upon the top of the plant, puts forth leaves, falls, and takes root. When the delicate plant shoots up from the earth, it would run too great a risk if it were immediately exposed to the air and influence of the sun. Its parts therefore remain folded close to each other, nearly the same as when in the seed. But as the root grows strong and branches out, it furnishes the superior vessels with an abundance of juice, by means of which all the organs are developed. At first the plant is nearly gelatinous; but it soon acquires more firmness, and continually increases in size. This short account of the germination of seeds suffices to shew us how many preparations and means nature uses to produce a single plant. When therefore we see a seed that we have placed in the earth sprout, we shall no longer consider it as beneath our notice, but shall rather be disposed to regard it as one of those wonders of nature which have excited the observation and attention of some of the greatest of men.

MAY IX.

Of the Chick in the Egg

WE are under considerable obligation to those naturalists who have made laborious researches and investigations into the nature of generation, and the