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XX. Of Animated Nature.

52. Animals are a class of beings differently organized from vegetables; because they have different destinations, have different habits, and have the power of moving from place to place, called the faculty of loco-motion.

See, thro' this air, this ocean, and this earth,
All matter quick, and bursting into birth.
Above, how high progressive life may go!
Around, how wide! how deep extend below
Vast chain of being! which from Gop began,
Natures ethereal, human, angel, man,

Beast, bird, fish, insect, what no eye can see,
No glass can reach; from Infinite to thee,
From thee to nothing.

POPE

Obs. The principal object of the study of natural history, is to teach us the characteristics, or distinctive marks of each individual natural object, called classification. To distinguish a species from all others that exist in nature, it is necessary to express in its characters almost the whole of its properties. A number of species brought together, constitutes a genus or tribe. Those properties which are common to all genera, compose a cha racter that distinguishes this assemblage or group from all other groups. Such an assemblage is called an order. By bringing together such orders as are more nearly allied, we form a more general assemblage, called a class; and by the union of several classes, we obtain a higher division, to which naturalists have given the name of kingdom.

453. When the all-wise Creator determined on making beings which should be able to move from place to place, he contrived for them a different organization from that of beings which were fixed.

As moveable beings could not have their roots in the ground, he provided them with the cavity

of the stomach, in which they were to carry about what should be equivalent to the soil for plauts and the suckers of their nutriment eentering in that cavity, were destined to act like the roots of plants in the soil.

154. Hence, in all animals, exists the necessity of eating frequently, to fill the cavity of the stomach; hence the folly and mischief of filling it with heterogeneous and unnatural substances; it being the object of nature simply to extract from the matter in the stomach a single uniform milky substance called chyle; no other juice but chyle being admitted into the animal sys tem, the rest being rejected and expelled.

455. As animals were intended to move about, the perfect are therefore provided with eyes, to see objects which might endanger their exist ence; with cars to hear, for a similar reason; with a voice to warn others, or to obtain assistance in danger.

Hence, also, they were provided with the senses of smelling and tasting, to discriminate the food which was proper for the stomach; and with the sense of feeling, or irritability, to secure their identities, and excite them to action.

And though things sensible be numberless,
But only five the senses' organs be

And in those five, all things their forms express,
Which we can touch, taste smell, or hear, or see.

456. The organs of sense and the powers of volition proceed from the head and brain, by the nerves, which direct the muscles and tendons; but the functions of animal life are sus

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tained by a simple, yet wonderful arrangement, in the stomach and cavities of the body.

The heart is the centre of a thousand tubes, called arteries; and by its never-ceasing contractions, it carries the blood through them, to all parts of the frame, diffusing every where warmth and life,

457. The blood of a man, thus driven by the contraction of the heart (a force like that by which water is driven out of a syringe of bladder), weighs 30 pounds; and, as this is the stock of the precious fluid possessed by each of us, and our lives depend on its constant circulation, it is not allowed to remain at the extremity of the arteries, but is there taken up by another set of tubes called veins, and by them brought back again to the heart.

458. Thus, there is a constant circulation, outward and inward, of this same blood, at the rate of an ounce to each contraction, from the heart through the arteries, and back to the heart by the veins. To warm, revive, nourish it, and keep up its quantity, there are various other wonderful, but very simple contrivances.

Were once the energy of air deny'd,

The heart would cease to pour its purple tide;
The purple tide forget its wonted play,
Not back again pursue its curious way.

459. The heart consists of four cavities, from one of which called the left ventricle, the blood is driven into the arteries through the body; by another, called the right auricle, it is received back again by the veins: it then passes into the

right ventricle, whence it is forced into the Jungs.

Having there been revivified by coming into contact with the air, it is carried back by a set of veins into the left auricle, and, from thence, into the left ventricle, where it began its course; it is then again forced into the arteries, brought back by the veins, &c., till the end of life.

460. The lungs are a large spongy substance filling nearly the whole cavity of the chest, which rises as they fill, and falls as they empty, in respiring air through the mouth and nostrils.

The act of respiration is performed about 20 times in a minute; and about 40 cubic inches of air are respired every time; of which 2 inches of oxygen are absorbed by the blood on the lungs, producing, at the same instant, 98 degrees of vital heat, and restoring the veinous blood to its bright red colour.

Obs.---The lights used in families to feed ents, are the lungs of sheep or oxen, and are exactly similar to the longs of man, On inspection, they will be found to be wonderfully adapted to their design of bringing the nie in contact with the blood. Any rupture in this tender fabric, or defect in their action, leads to that fatal class of diseases, called Consumption.

461. Four thousand times in every hour, each cavity of the heart is called into action: and all the blood in the body passes through the heart 14 times in every hour.

The arteries, into which it is forced, branch in every direction through the body, like the roots, branches, and leaves of a tree, running through the substance of the bones, and every

part of the animal substance, till they are lost in such fine tubes as to be wholly invisible. .462. In this manner, they distribute nourishment; supply perspiration; and renew all the waste of the skin; and, by passing through glands in every part of the body, all the vari ous animal secretions are elaborated.

In the parts where the arteries are lost to the sight, the veins take their rise, and in their commencement are also imperceptible. The blood is then of a dark colour; and, as it returns to the heart with a less impetus, there is always twice as much blood in the veins as in the arteries.

463. As the blood, in this discoloured state, has lost some of its vital power, it is driven through the lungs, and its colour is restored, but on its passage back to the heart, it also receives a supply of a new fluid extracted from the food of the animal in the stomach and intestines.

The loss of weight in a human body by perspiration in 24 hours is about four pounds; and what is gained by the inspiration of air into the lungs, is lost by the expulsion of moisture, and of gas generated in the lungs.

464. The motion of the lungs is preserved by that of the chest containing them; that of the heart, may be felt on the left breast; and the circulation of the blood, by the action of the pulse in various parts of the body, and particu larly at the wrist.

Ta ohildren, the pulse gives 120 strokes in a

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