animals have none on the lower eye-lid, and man's upper eye-lid has more than the lower. The eyebrows have but two sorts of motions, which are performed by the assistance of the muscles of the fore-head. By means of one they rise, and by means of the other they fall down and draw together. The eye-lids guard the eye, and prevent the cornea from drying. The upper one can of itself rise and fall. The under one moves but little. Though we can at will move our eye-lids, it is not in our power to keep them open, when fatigue and sleep weigh them down. The forehead is a very important part of the face, and adds considerably to its beauty, if it is well proportioned, neither too full nor too flat, too large nor too small, and if the hair growing well, forms the outline and ornament of it. The nose is the part of the face which projects most, but is the least moveable; and as it is seldom put in motion, but in violent passions, it serves more for the beauty of the whole than for any expression resulting from it. The mouth and lips, on the contrary, are susceptible of many changes; and, next to the eyes, it is the mouth which best expresses the passions, by the variety of forms it assumes. The organ of the voice also helps to animate and set it in play. The red colour of the lips, and the whiteness of the teeth, add to the charms of the face.

We have hitherto only examined the human face relatively to the regularity and beauty of the parts which compose it, without discovering the use and several purposes of those parts. But under this one point of view we already perceive the infinite wisdom of him who has, throughout all his works, united the useful with the beautiful.

JULY

JULY XXVII.

ON THE GRAVITY OF BODIES.

GOD has endowed bodies with a force which acts at all times, in all places, and in all senses. If a body endeavours to move towards one point more forcibly than to another, we say that it gravitates towards that point. For experience teaches us, that bodies are inclined to descend; or, that if they are far from the surface of the earth without support, they fall on it in a perpendicular line. It is by no means in the body itself that we must seek the cause of its weight; for a body which falls remains in the state it was put, till some exterior cause changes it. It is equally impossible that the air should occasion this gravity, since being itself heavy, it ought rather to lessen the swiftness of the fall of bodies. We must therefore seek the cause elsewhere. Perhaps the opinion nearest truth, is that which supposes the earth to have the virtue of attracting bodies placed at a certain distance, as the magnet attracts iron: Or else possibly it may be imputed to a foreign substance distributed throughout all bodies. But though we cannot positively ascertain the cause of weight, nothing is more evident than the advantages which accrue from it. Without it we should not be able to move as we do. Our centre of gravity is about the middle of our bodies. When we raise the right foot, we make the left to be the centre: If we then bend our body forward, we are near falling; but by putting out the right foot, we prevent the fall, and make a step. Thus our walk is, in some respects, a continual course of falls; during which the centre of

VOL. II.

K

gravity

gravity is preserved between our feet. This is the reason we bend forward in going up a hill, and backward in coming down it. We also lean forward when we carry a load on our shoulders, and backward when we carry it before us. All this is according to the laws of gravity, which govern the motions of animals when they walk, swim, or fly. These same laws govern the motions of the immense bodies which roll in the firmament: The sun attracts the planets; and each planet in its turn attracts its satellites: Or, what is just the same, the planets gravitate towards the sun, and the satellites towards the planets; for a body made to turn round, always flies in a direct line from its centre, if it meets with no obstacle in its way. It is with the greatest swiftness that the planets run their course; and the moon is not fastened by a chain to our earth. It seems then, as if a motion so rapid as that of the moon, must throw it very far from us in the immeasurable space, if there was not a force which continually pushes it towards our globe; and which counteracts the force that removes it from hence. That first force is the gravitation of the moon towards the earth. If our earth was either lighter or heavier than it is, what would be the consequence? It would either draw too near or too far from the sun. In the first case, the heat would be insupportable; and in the latter, the cold would be equally on: every thing in our globe would be consumed or frozen. What would then become of the seasons, and a thousand things so indispensible for man, and so necessary for his happiness?

Here again, then, O supreme Wisdom! I find a monument of thy wonders. By a means so small in appearance, thou givest motion to the celestial bodies, and to all animals. By the laws of gravity

alone,

alone, thou preventest the least grain of sand from being lost upon this or any other globe. But it is in this that the greatness of thy power and wisdom consists, that often the greatest and most astonishing effects are produced by means that appear to us the most insignificant.

.....

JULY XXVIII.

NUMBER OF EFFECTS IN NATURE PROCEEDING FROM ONE AND THE SAME CAUSE.

THE whole of nature is one endless chain of causes and effects; and as all parts of the universe are connected together, each motion, each event, depends on a preceding cause; and will, in its turn, become a cause of the effects which follow it. The whole constitution of the world may convince us, that it is not chance, but a divine power, and a wisdom beyond all conception, which first erected this wonderful fabric, and impressed motion upon its different parts, and regulated the great chain of events depending on and succeeding each other. This degree of knowledge is not difficult to acquire; for though that which we have of nature is very limited, we still see numberless important effects derived from causes evident to the human understanding. Many natural phenomena may furnish examples of this. What variety of effects does the heat of the sun visibly produce? It not only contributes to preserve the life of multitudes of animals, but also to the vegetation of plants, the ripening of corn and fruit, the fluidity of water, the exhalation of vapours, and formation of clouds, with

cross over.

out which neither rain nor dew would fall upon the earth. The air likewise is so constituted as to fulfil several purposes at once. By means of this element, the animal bodies are preserved, the lungs are relieved, and all the vital motions acquire force. It is the air which kindles fire, and nourishes the flame. The air, by its motion and undulation, conveys every sort of sound to the ear. It gives a spring to the winged animals; and enables them to fly from place to place. It opens to man an casy passage through the seas; the vast expanse of which he could not otherwise It is the air which supports the clouds in the atmosphere, till becoming too heavy, they fall again in rain. It is the air which prolongs the day by morning and evening twilights; and without it the gift of speech, and the sense of hearing, would be useless to us. All these blessings, and many more, depend on the formation of the air in which we live and breathe. This wonderful element, which surrounds our globe, which is too subtile to be visible to us, and yet so strong, that no element can resist its force, is it not a striking proof of the wisdom of our Creator? The force of gravitation alone, which exists in every thing, holds the earth firm, preserves the mountains, and renders water fluid. It confines the ocean in its depths, and the earth within the circle prescribed. It maintains each being in its place throughout all nature; and preserves between the celestial bodies the proper distance from each other. Who can describe the many properties of water! In general, it serves to dilute, to soften, to mix a great many bodies which we could not otherwise make use of. It is the most wholesome drink: It is the best nourishment for plants: It turns mills and several

other