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veins. The heart is enclosed in the pericardium, a membranous bag, which contains a quantity of water, or lymph. This water lubricates the heart, and facilitates all its motions. The heart is the general reservoir of the blood. When the heart contracts the blood is propelled from the right ventricle into the lungs, through the pulmonary arteries, which, like all the other arteries, are furnished with valves that play easily forward, but admit not the blood to return toward the heart. The blood, after circulating through the lungs, and having there been revivified by coming in contact with the air, and imbibing a portion of its oxygen, returns into the left auricle of the heart, by the pulmonary vein. At the same instant, the left ventricle drives the blood into the aorta, a large artery which sends off branches to supply the head and arms. Another large branch of the aorta descends along the inside of the back-bone, and detaches numerous ramifications to nourish the bowels and inferior extremities. After serving the most remote extremities of the body, the arteries are converted into veins, which, in their return to the heart, gradually unite into larger branches, till the whole terminate in one great trunk, called the vena cava, which discharges itself into the right auricle of the heart, and completes the circulation. Each ventricie of the heart is reckoned to contain about one ounce, or two tablespoonsfull of blood. The heart contracts 4000 times every bour; and, consequently, there passes through it 250 pounds of blood in one hour. And if the inass of blood in a human body be reckoned at an average of twenty-five pounds, it will follow that the whole mass of blood passes through the heart, and consequently through the thousands of ramifications of the veins and arteries, fourteen times every hour, or about once every four minutes. We may acquire a rude idea of the force with which the blood is impelled from the heart, by considering the velocity with which water issues from a syringe, or from the pipe of a fire-engine. Could we behold these rapid motions incessantly going on within us, it would overpower our minds with astonishment, and even with terror. We should be apt to feel alarmed on making the smallest exertion, lest the parts of this delicate machine should be broken or deranged, and its functions interrupted. The arteries, into which the blood is forced, branch in every direction through the body, like the roots and branches of a tree; running through the substance of the bones, and every part of the animal frame, till they are lost in such fine tubes as to be wholly invisible. In the parts where the arteries are lost to the sight, the veins take their rise, and in their commencement are also imperceptible.

Respira ion.-The organs of respiration are the lungs. They are divided into five lobes; three of which lie on the right, and two on the

left side of the thorax. The substance of the lungs is chiefly composed of infinite ramifica tions of the trachea, or windpipe, which, after gradually becoming more and more minute, terminate in little celis, or vesicles, which have a free communication with one another. At each inspiration, these pipes and cells are filled with air, which is again discharged by expiration. In this manner, a circulation of air, which is necessary to the existence of men and o her animals, is constantly kept up as long as life remains. The air-cells of the lungs open into the windpipe, by which they communicate with the external atmosphere. The whole internal structure of the lungs is lined by a transparent membrane, estimated at only the thousandth part of an inch in thickness; but whose surface, from its various convolutions, measures fifteen square feet, which is equal to the external surface of the body. On this thin and extensive membrane innumerable veins and arteries are distributed, some of them finer than hairs; and through these vessels all the blood of the system is successively propelled, by a most curious and admirable mechanism. It has been computed, that the lungs, on an average, contain about 280 cubic inches, or about five English quarts of air. At each inspiration, about forty cubic inches of air are received into the lungs, and the same quantity discharged at each expiration. On the supposition that 20 respirations take place in a minute, it will follow, that, in one minute we inhale 800 cubic inches; in an hour, 48,000; and in a day, one million, one hundred and fifty-two thousand cubic inches-a quantity which would fill seventyseven wine hogsheads, and would weigh fiftythree pounds troy. By means of this function, a vast body of air is daily brought into contact with the mass of blood, and communicates to it its vivifying influence; and, therefore, it is of the utmost importance to health, that the air, of which we breathe so considerable a quantity, should be pure, and uncontaminated with noxious effluvia.

Digestion. This process is performed by the stomach, which is a membranous and muscular bag, furnished with two orifices. By the one, it has a communication with the gullet, and by the other, with the bowels. The food, after being moistened by the saliva, is received into the sto mach, where it is still farther diluted by the gastric juice, which has the power of dissolving every kind of animal and vegetable substance. Part of it is afterwards absorbed by the lymphatic and lacteal vessels, and carried into the circulating system, and converted into blood for supplying that nourishment which the perpetual waste of our bodies demands.

Perspiration is the evacuation of the juices of the body through the pores of the skin. It has been calculated that there are above three hundred thousand millions of pures in the glands of the

skin which covers the body of a middle-sized man. Through these pores, more than one-half of what we eat and drink passes off by insensible perspiration. During a night of seven hours' sleep, we perspire about forty ounces, or two pounds and a half. At an average, we may estimate the discharge from the surface of the body, by sensible and insensible perspiration, at from half an ounce to four ounces an hour. This is a most wonderful part of the animal economy, and is absolutely necessary to our health, and even to our very existence. When partially obstructed, colds, rheumatisms, fevers, and other inflammatory disorders, are produced; and were it completely obstructed, the vital functions would be clogged and impeded in their movements, and death would inevitably ensue.

Sensation. The nerves are generally considered as the instruments of sensation. They are soft white cords which proceed from the brain and spinal marrow. They come forth originally by pairs. Ten pair proceed from the medullary substance of the brain, which are distributed to all parts of the head and neck. Thirty pair proceed from the spinal marrow, through the vertebræ, to all the other parts of the body; being forty in all. These nerves, the ramifications of which are infinitely various and minute, are distributed upon the heart, lungs, blood-vessels, bowels, and muscles, till they terminate on the skin or external covering of the body. Impressions of external objects are received by the brain from the adjacent organs of sense, and the brain exercises its commands over the muscles and limbs by means of the nerves.

Without prosecuting these imperfect descriptions farther, shall conclude this very hasty sketch with the following summary of the parts of the body, in the words of Bonnet. "The bones, by their joints and solidity, form the foundation of this fine machine: the ligaments are strings which unite the parts together: the muscles are fleshy substances, which act as elastic springs to put them in motion: the nerves, which are dispersed over the whole body, connect all the parts together: the arteries and veins, like rivulets, convey life and health throughout: the heart, placed in the centre, is the focus where the blood collects, or the acting power by means of which it circulates and is preserved: the lungs, by means of another power, draw in the external air, and expel hurtful vapours: the stomach and intestines are the magazines where every thing that is required for the daily supply is prepared: the brain, that seat of the soul, is formed in a manner suitable to the dignity of its inhabitant: the senses, which are the soul's ministers, warn it of all that is necessary either for its pleasure or use.* Adorable Creator! with what wonderful art hast thou formed us!

• Contemplation of Nature, vol. i. p. 64.

Though the heavens did not exist to prociaim thy glory; though there were no created being on earth but myself, my own body might suffice to convince me that thou art a God of unlimited power and infinite goodness."

This subject suggests a variety of moral and religious reflections, but the limits to which I am confined will permit me to state only the following:

1. The economy of the human frame, when seriously contemplated, has a tendency to excite admiration and astonishment, and to impress us with a sense of our continual dependence on a suTMperior power. What an immense multiplicity of machinery must be in action to enable us to breathe, to feel, and to walk! Hundreds of bones, of diversified forms, connected together by various modes of articulation: hundreds of muscles to produce motion, each of them acting in at least ten different capacities, (see p. 40;) hundreds of tendons and ligaments to connect the bones and muscles; hundreds of arteries to convey the blood to the remotest part of the system; hundreds of veins to bring it back to its reservoir the heart; thousands of glands secreting humours of various kinds from the blood; thousands of lacteal and lymphatic tubes, absorbing and conveying nutriment to the circulating fluid; millions of pores, through which the perspiration is continually issuing; an infinity of ramifications of nerves, diffusing sensation throughout all the parts of this exquisite machine; and the heart at every pulsation exerting a force of a hundred thousand pounds, in order to preserve all this complicated machinery in constant operation! The whole of this vast system of mechanism must be in action before we can walk across our apartments! We admire the operation of a steam-engine, and the force it exerts. But, though it is constructed of the hardest materials which the mines can supply, in a few months some of its essential parts are worn and deranged, even though its action should be frequently discontinued. But the animal machine, though constructed, for the most part, of the softest and most flabby substances, can go on without intermission in all its diversified movements, by night and by day, for the space of eighty or a hundred years; the heart giving ninety-six thousand strokes every twenty-four hours, and the whole mass of blood rushing through a thousand pipes of all sizes every four minutes! And is it man that governs these nice and complicated movements? Did he set the heart in motion, or endue it with the muscular force it exerts? And when it has ceased to beat, can he command it again to resume its functions? Man knows neither the secret springs of the machinery within him, nor the half of the purposes for which they serve, or of the movements they perform. Can any thing more strikingly demonstrate our dependence

every moment on a superior Agent, and that it is in God we live, and move, and have our being? Were a single pin of the machinery within us, and over which we have no control, either broken or deranged, a thousand movements might instantly be interrupted, and our bodies left to crumble into the dust.

It was considerations of this kind that led the celebrated physician Galen, who was a skeptic in his youth, publicly to acknowledge that a Supreme Intelligence must have operated in ordaining the laws by which living beings are constructed. And he wrote his excellent treatise "On the uses of the parts of the human frame," as a solemn hymn to the Creator of the world. "I first endeavour from His works," he says, "to know him myself, and afterwards, by the same means, to show him to others; to inform them, how great is his wisdom, his goodness, his power." The late Dr. Hunter has observed, that astronomy and anatomy are the studies which present us with the most striking view of the two most wonderful attributes of the Supreme Being. The first of these fills the mind with the idea of his immensity, in the largeness, distances, and number of the heavenly bodies; the last astonishes us with his intelligence and art, in the variety and delicacy of animal mechanism. 2. The study of the animal economy has a powerful tendency to excite emotions of gratitude. Man is naturally a thoughtless and ungrateful creature. These dispositions are partly owing to ignorance of the wonders of the human frame, and of the admirable economy of the visible world; and this ignorance is owing to the want of those specific instructions which ought to be communicated by parents and teachers, in connexion with religion. For, there is no rational being who is acquainted with the structure of his animal system, and reflects upon it with the leas degree of attention, but must feel a sentiment of admiration and gratitude. The science which unfolds to us the economy of our bodies, shows us on what an infinity of springs and motions, and adaptations, our life and comfort depend. And when we consider, that all these movements are performed without the least care or laborious effort on our part, if we be not altogether brutish, and insensible of our dependence on a superior Power, we must be filled with emotions of gratitude towards Him "whose hands have made and fashioned us, and who giveth us life, and breath, and all things." Some of the motions to which I have adverted depend upon our will; and with what celerity do they obey its commands? Before we can rise from our chair, and walk across our apartment, a hundred muscles must be set in motion; every one of these must be relaxed or constricted, just to a certain degree, and no more; and all must act harmoniously at the same instant of time; and, at the command of the soul, all these movements

are instantaneously performed. When I wish to lift my hand to my head, every part of the body requisite to produce the effect is put in mo. tion: the nerves are braced, the muscles are stretched or relaxed, the bones play in their sockets, and the whole animal machine concurs in the action, as if every nerve and muscle had heard a sovereign and resistless call. When I wish the next moment to extend my hand to my foot, all these muscles are thrown into a different state, and a new set are brought along with them into action and thus we may vary, every moment, the movements of the muscular system, and the mechanical actions it produces, by & simple change in our volition. Were we not daily accustomed to such varied and voluntary movements, or could we contemplate them in any other machine, we should be lost in wonder and astonishment.

Besides these voluntary motions, there are a thousand important functions which have no dependance upon our will. Whether we think of it or not, whether we are sleeping or waking, sitting or walking-the heart is incessantly exert ing its muscular power at the centre of the sys tem, and sending off streams of blood through hundreds of pipes; the lungs are continually expanding and contracting their thousand vesicles, and imbibing the vital principle of the air; the stomach is grinding the food; the lacteals and lymphatics are extracting nourishment for the blood; the liver and kidneys drawing off their secretions; and the perspiration issuing from millions of pores. These, and many other important functions with which we are unacquainted, and over which we have no control, ought to be regarded as the immediate agency of the Deity within us, and should excite our incessant admiration and praise.

There is one peculiarity in the constitution of our animal system, which we are apt to overlook, and for which we are never sufficiently grateful. and that is, the power it possesses of self-restoration. A wound heals up of itself; a broken bone is made firm again by a callus; and a dead part is separated and thrown off. If all the wounds we have ever received were still open and bleeding afresh, to what a miserable condition should we be reduced? But by a system of internal powers, beyond all human comprehension as to the mode of their operation, such dismal effects are effectually prevented. In short, when we consider that health depends upon such a nume rous assemblage of moving organs, and that a single spring out of action might derange the whole machine, and put a stop to all its complicated movements, can we refrain from joining with the psalmist, in his pious exclamation, and grateful resolution, "How precious are thy wonderful contrivances concerning me, O God! how great is the sum of them! will praise thee; for I am fearfully and wonderfully made. Mat.

vellous are thy works, and that my soul knoweth right well."

Omitting the consideration of several other departments of science, I shall in the mean time notice only another subject connected with religion, and that is History.

HISTORY.

History embraces a record and description of past facts and events, in reference to all the nations and ages of the world, in so far as they are known, and have been transmitted to our times. As natural history contains a record of the operations of the Creator in the material world, so sacred and civil history embraces a record of his transactions in the moral and intellectual world, or, in other words, a detail of the plans and operations of his providence, in relation to the inhabitants of our globe. Through the medium of Sacred History, we learn the period and the manner of man's creation-the reason of his fall from the primitive state of integrity in which he was created, and the dismal consequences which ensued: the various movements of Providence in order to his recovery, and the means by which human redemption was achieved; the manner in which the gospel was at first promulgated, the countries into which it was carried, and the important effects it produced. Through the medium of Civil History we learn the deep and universal depravity of mankind, as exhibited in the wars, dissensions, and ravages, which have desolated our fallen race, in every period, and in every land; we learn the desperate wickedness of the human heart, in the more private acts of ferocity, cruelty, and injustice, which, in all ages, men have perpetrated upon each other; we behold the righteousness of the Supreme Ruler of the world, and the equity of his administration, in the judgments which have been inflicted on wicked nations-and the improbability, nay, the impossibility, of men being ever restored to moral order and happiness, without a more extensive diffusion of the blessings of the gospel of peace, and a more cordial acquiescence in the requirements of the divine laws.

Such being some of the benefits to be derived from history, it requires no additional arguments to show, that this branch of knowledge should occasionally form a subject of study to every intelligent Christian. But in order to render the study of history subservient to the interests of religion, it is not enough merely to gratify our curiosity and imagination, by following out a succession of memorable events, by tracing the progress of armies and of battles, and listening to the groans of the vanquished, and the shouts of conquerors. This would be to study history merely as skeptics, as atheists, or as writers of novels. When we contemplate the facts which he historian presents to our view, we ought to 15

raise our eyes to Him who is the Governor among the nations, "who doth according to his will in the armies of heaven, and among the inhabitants of the earth," and who overrules the jarring interests of mortals, for promoting the prosperity of that kingdom which shall never be moved. We should view the immoral propensities and dispositions of mankind as portrayed in the page of history, as evidences of the depravity of our species, and as excitements to propagate, with unremitting energy, the knowledge of that religion, whose sublime doctrines and pure precepts alone can counteract the stream of human corruption, and unite all nations in one harmonious society. We should view the contests of nations, and the results with which they are ac companied, as guided by that invisible Hand, which "mustereth the armies to the battle;" and should contemplate them either as the accomplishment of divine predictions, as the inflictions of retributive justice, as paving the way for the introduction of rational liberty and social happiness among men, or as ushering in that glorious period, when "the knowledge of the Lord shall cover the earth," and the nations shall learn war no more.

Thus I have taken a very cursory survey of some of those sciences which stand in a near relation to the objects of religion; and which may, indeed, be considered as forming so many of its subordinate branches. There are many other departments of knowledge, which, at first view, do not seem to have any relation to theological science; and yet, on a closer inspection, will be found to be essentially connected with the several subjects of which I have been treating For example-some may be apt to imagine that arithmetic, geometry, trigonometry, and other branches of mathematics, can have no relation to the leading objects of religion. But if these sciences had never been cultivated, the most important discoveries of astronomy, geography, natural philosophy, and chymistry, would never have been made; ships could not have been navigated across the ocean; distant continents, and the numerous" isles of the sea," would have remained unexplored, and their inhabitants left to grope in the darkness of heathenism; and most of those instruments and engines by which the condition of the human race will be gradually meliorated, and the influence of Christianity extended, would never have been invented. Such is the dependence of every branch of useful knowledge upon another, that were any one portion of science, which has a practical tendency, to be discarded, it would prevent, to a certain degree, the improvement of every other. And, consequently, if any one science can be shown to have a connexion with religion, all the rest must likewise stand in a certain relation to it. It must, therefore, have a pernicious effect on the

ninds of the mass of the Christian world, when preachers, in their sermons, endeavour to undervalue scientific knowledge, by attempting to contrast it with the doctrines of revelation. It would be just as reasonable to attempt to contrast the several doctrines, duties, and facts recorded in the New Testament with each other, in order to deermine their relative importance, and to show which of them might be altogether overlooked and discarded. The series of facts and of divine revelations comprised in the bible; the moral and political events which diversify the history of nations; and the physical operations that are going on among the rolling worlds on high, and in the chymical changes of the invisible atoms of matter, are all parts of one comprehensive system, under the direction of the Eternal Mind; every portion of which must have a certain relatien to the whole.

And, therefore, instead of attempting to degrade one part of the divine fabric in order to enhance another, our duty is to take an expansive view of the whole, and to consider the symmetry and proportion of its parts, and their mutual bearings and relations-in so far as our opportunities, and the limited faculties of our minds, will permit.

If the remarks which have been thrown out in this chapter, respecting the connexion of the sciences with religion, have any foundation, it will follow-that sermons, lectures, systems of divinity, and religious periodical works, should embrace occasional illustrations of such subjects, for the purpose of expanding the conceptions of professed Christians, and of enabling them to take large and comprehensive views of the per

fections of the providence of the Almighty. I is much to be regretted, that so many members of the Christian church are absolute strangers to such studies and contemplations; while the time and attention that might have been devoted to such exercises, have, in many cases, been usurped by the most grovelling affections, by foolish pursuits, by gossiping chit-chat, and slanderous conversation. Shall the most trifling and absurd opinions of ancient and modern heretics be judged worthy of attention, and occupy a place in religious journals, and even in discussions from the pulpit, and shall "the mighty acts of the Lord," and the visible wonders of his power and wisdom, be thrown completely into the shade? To survey, with an eye of intelligence, the wide-extended theatre of the divine operations-to mark the agency of the Eternal Mind in every object we behold, and in every movement within us and around us, are some of the noblest attainments of the rational soul; and, in conjunction with every cther Christian study and acquirement, are calculated to make "the man of God perfect, and thoroughly furnished unto every good work." By such studies, we are, in some measure, assimilated to the angelic tribes, whose powers of intellect are for ever employed in such investigations and are gradually prepared for bearing a part in their immortal hymn-"Great and marvellous are thy works, Lord God Almighty; just and true are thy ways, thou King of saints. Thou art wor thy to receive glory, and honour, and power; for thou hast created all things, and for thy pleasure they are and were created."

CHAPTER III.

THE RELATION WHICH THE INVENTIONS OF HUMAN ART BEAR TO THE OBJECTS OF RELIGION.

In this chapter, I shall briefly notice a few philosophical and mechanical inventions which nave an obvious bearing on religion, and on the general propagation of Christianity among the

nations.

The first, and perhaps the most important, of the inventions to which I allude, is the Art of Printing. This art appears to have been invented (at least in Europe) about the year 1430, by one Laurentius, or Lawrence Koster, a native of Haerlem, a town in Holland. As he was waking in a wood near the city, he began to cut some letters проп the rind of a beach tree, which, for the sake of gratifying his fancy, being impressed on paper, he printed one or two lines as specimen for his grandchildren to follow. This

having succeeded, he meditated greater things, and, first of all, invented a more glutinous writing ink; because he found the common ink sunk and spread; and thus formed whole pages of wood, with letters cut upon them.* By the gradual

has been claimed by other cities besides Haerlem, I am aware, that the honour of this invention particularly by Strasburg, and Mentz, a city of Ger many; and by other individuals besides Laurentius, chiefly by one Fust, commonly called Dr. Faustus; by Schoeffer, and by Gutenberg. It appears that the art, with many of its implements, was stolen from Laurentius by one of his servants, whom he had bound, by an oath, to secrecy, who fled to Mentz, and first commenced the process of printing in that city. Here the art was improved by Fust and Schoef fer, by their invention of metallic, instead of wooden types, which were first used. When Fust was in

Paris, disposing of some bibles he had printed, at

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