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immediately strike us. A plant is a system of life, but insensitive, and fixed to a certain spot.
An animal hath voluntary motion, sense, or perception, and is capable of pain and pleasure. Yet in the construction of each there are some general principles which very obviously connect them. It is literally as well as metaphorically true, that trees have limbs, and an animal body branches. cular system is also common to both, in the channels of which life is maintained and circulated. When the trachea, with its branches in the lungs, or the veins and arteries, or the nerves, are separately represented, we have the figure of a tree. The leaves of trees have a fibrous and a fleshy part; their bark is a covering, which answers to the skin in animals. An active vapour pervades them both, and perspires from both, which is necessary to the preservation of health and vigour.
The parallel might be extended to their wounds and distempers: but we must not be too minute, when our purpose is rather to raise devotion than to satisfy curiosity. However, it ought not to be omitted, that the vis vitæ, or involuntary, mechanical force of animal life, iş kept up by the same elements
which act upon plants for their growth and support.
The organs of respiration, acted upon by the air, are as the first wheel in a machine, which receives the moving power; heat preserves the fluidity of the blood and humours, and acts as an expanding force in the stomach, heart, and blood-vessels ; which force is counteracted from without by the atinospherical pressure; for the want of which, the vessels would be ruptured by the prevailing of the force within.
The nerves form another distinct branch of the animal system, and are accommodated by the Creator to the action of that subtile, forcible fluid, which in its different capacities we sometimes call light, and sometimes ether. Late experiments have shewn us how little this acts on the blood-vessels, and how powerfully on the nerves and muscles, the functions of which it will therefore restore, and hath done in several cases, when they have been impaired by diseases or accidents.
The animal mechanism, and the forces of life, are things fearful and wonderful in thema selves, and of such deep research, that I am afraid of venturing too far; but thus far I think we are safe, that animal life, considered only as motion, is maintained like the other motions of nature, by the action of 'contrary forces; in which there is this wonderful property, that neither appears to have the priority; and their joint effect is a motion, which in theory is perpetual. The flame of a candle cannot burn without fire, nor be lighted without air: which of these is first we cannot say, for they seem co-instantaneous; and they continue to work together till the matter fails which they work upon.
Thus, when an animal is born into the world, and the candle of life is lighted up, it is hard to give any precedence to the elementary powers which support it. The weight of the atmosphere forces into the lungs, as soon as they are exposed to its action, that air which is the breath of life ; but this could not happen, unless the more subtile element were to occasion a rarefaction within : and this reciprocation, once begun, is continued through life: though it will fail if either of the elements cease to act upon it. With extreme cold, the circulation of the blood will stop; and the want of air, or the admission of that which is improper, will extinguish the vital motion in the lungs. But here, as the power
of the Creator is found to maintain a vegetable life in plants, where the necessary means seem to be wanting ; so, when we think the mechanism of animal life is understood, and that heat, and respiration, and circulation, are all necessary to it, - we look farther, and find animals living without respiration; some totally, and others (which is more wonderful) occasionally. Some are comparatively, if not positively, cold in their temperature; as those which lie under water in the winter months. These are unable to endure that degree of heat which is the life of others: as there are plants which fix themselves upon the bleak head of a mountain, and will never be reconciled to a richer soil, and a warmer air. Thus doth the . wisdom of God work by various ways to the same end; and animal life is maintained where, the means of life seem to be wanting. That the elements which act upon the barometer and thermometer are necessary to animal life cannot be doubted, however the receptive faculties of organised matter may be varied. We have musical sounds from the pipe, the string, and the drum; but never without the musical elernent of air.
If we enquire how the wisdom of the. Creator is displayed in the different kinds of
animals, the field is so large, that the time will permit us to consider those only to which we are directed by the words of the text, beasts of the earth and cattle after their kind. And that we may proceed herein without confusion, we must take advantage of a plain and significant distinction which the Holy Scrip ture hath proposed to us for our learning.
The law of Moses, in the with chapter of Leviticus, divides the brute creation into two grand parties, from the fashion of their feet, and their manner of feeding; that is, from the parting of the hoof, and the chewing of the cud; which properties are indications of their general characters, as wild or tame. For the dividing of the hoof and the chewing of the cud: are peculiar to those cattle which are serviceable to man's life, as sheep, oxen, goats, deer, and their several kinds. These are shod by the Creator for a peaceable and inoffensive progress through life; as the Scripture exhorts us to be shod in like manner with the prepardtion of the Gospel of Peace. They live temperately upon herbage, the diet of students and saints; and after the taking of their food, chew it deliberately over again for better digestion; in which act they have all the appears ance a brute can assume of pensiveness or me