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THE LIBRARY 
 
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 GIFT OF 
 
 Catherine K, "Wheeler 
 

 C i 1 ^ C H I S M 
 
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 OF 
 
 NATURAL THEOLOGY. 
 
 "evert HOrSE IS BtJILDEB BY SOME MAN 
 BUT HE THAT BUILT ALL THI5GS IS COD.' 
 
 BY I. NICHOLS, D. D. 
 
 PASTOR OF THE FIRST CHURCH IK PORTLAND. 
 
 SECOND edition: 
 
 WITH ADDITIONS AND IMPROVEMENTS 
 \ 
 
 BOSTON: 
 PUBLISHED BY WILLIAM HYDE 
 
 1831. 
 
Entered, according to Act of Congress, in the year 1831, by 
 William Htde, in the Clerk's office of the District Court of 
 Massachusetts. 
 
 GIFT 
 
 PRESS 
 
 OP C. S. D. &C B. r. ORIFFIZt. 
 

 CATECHISM 
 
 OP 
 
 \ 
 
 \ 
 
 NATURAL THEOlrOGY 
 
 INTRODUCTION. 
 
 Teacher. What do you understand by Natural 
 Theology ? 
 
 A. Theology, derived from two Greek words em- 
 ployed to signify our knowledge of God, is divided 
 into two parts, natural and revealed. Revealed the- 
 ology embraces those extraordinary discoveries which 
 God has made to mankind in the holy scriptures. 
 Natural theology teaches what may be known of 
 God, from the manifestations of his existence and 
 perfections in the natural world. 
 
 T. What do the scriptures observe respecting 
 natural theology ? 
 
 A. While the scriptures principally require us to 
 know God, as he has revealed himself to us in his di- 
 
 *^ 421 
 
6 INTRODUCTION. 
 
 vine word, they also require us to contemplate his 
 being and providence, as they are manifested in the 
 objects of nature. Lift up your eyes on high, and 
 behold who hath created these things. They speak 
 of the works of creation as presenting the plainest 
 proofs of an all-powerful and divine Author. The 
 invisible things of him from the creation of the world 
 are clearly seen, being understood by the things ivhich 
 are made,, even his eternal power and Godhead. — 
 They invite our attention to the wonders of creation, 
 as a most noble and delightful study. The works of 
 the Lord are great, sought out of all them who have 
 pleasure therein. They call upon the heavens^ and 
 earth, the seas and mountains, the animal, the herb, 
 and every thing which exists, to celebrate the praises 
 of the Creator : that is, they require of us to study 
 his providence ourselves, as exhibited in these vari- 
 ous forms, and elevate our souls to him, in the con- 
 templation of that almighty power and munificence, 
 which are displayed in every part of the universe. 
 It was a common practice with our Saviour, in teach- 
 ing his disciples, to make use of the works of nature 
 in leading them to reflect on heavenly and spiritual 
 things. Behold the fowls of the air. Consider the 
 lillies of the field. 
 
 T. What other reasons recommend this study ? 
 
 A. While it is adapted to cultivate our devout 
 feelings, and render the universe a perpetual temple 
 for the worship of its infinite Author, the study of na- 
 ture is most worthy of a rational curiosity. It is suit- 
 ed to every capacity. It may be enjoyed in every 
 
NATURAL THEOLOGY. i 
 
 situation. Its field is boundless ; its novelty inex- 
 haustible. If the eminence of an artist attach a high- 
 er interest to his productions ; if we should crowd to 
 see the works of a Phidias, a Praxiteles, or a Rapha- 
 el, with what emotions should those objects be sur- 
 veyed, which lead up our thoughts to an Almighty 
 Author. Shall we reserve our curiosity for the im- 
 perfect exhibitions of our own limited powers, and be 
 indifferent to the study which reveals in every form . 
 the hand of Infinite Wisdom ? Whatever reason we 
 can imagine for the study of human inventions, a far 
 higher, surely, may be adduced for directing our at- 
 tention to those Divine contrivances which immeasur- 
 ably surpass them. There is scarcely an art but has 
 its more simple and admirable parallel in some natural 
 provision. Nature either furnishes the pattern, or ex- 
 emplifies the result in a more perfect manner. The 
 telescope was improved, and the first idea of it proba- 
 bly suggested, from an examination of the Eye. What 
 is the most finished statue, compared with the living 
 form ? The works of art are soon exhausted ; and 
 by a critical inspection we can easily discover blem- 
 ishes and imperfections in them. But the more close- 
 ly we examine their great originals in the vast king- 
 dom of nature, the more proofs do they afford us of 
 the perfection of the works of God, in comparison with 
 the highest efforts of human skill. Shall our interest 
 then be excited at hearing of any new engine or piece 
 of machinery which some one has invented? shall 
 novelty be attractive and almost irresistible, when 
 
8 INTRODUCTION. 
 
 there are these imperfect objects to call it forth ? and 
 shall we be indifferent to the innumerable wonders of 
 nature around us, the examination of whifch would 
 prove a sure mean of enlightening our minds, exalting 
 our thoughts, and advancing our piety ? 
 
 T. How do we arrive at the knowledge of an Al- 
 mighty Creator, from contemplating the spectacle of 
 the universe ? 
 
 A, The countless manifestations of design, and 
 the continued display of bountiful provisions through 
 all nature, are a proof of some designing power, and 
 of a power beneficent and good, that is, of the Being 
 whom we denominate God. If we should deem it 
 absurd to suggest that a watch was an accidental com- 
 bination of wheels and springs, not intended for any 
 purpose, how much more irrational to suppose tha:t so 
 many manifestations of design, in the universe, exist 
 without design ! When the humblest appearances of 
 order, arrangement, and adaptation to use, in any ob- 
 ject, even in a birdVuest, would lead us to pronounce 
 it not a casual formation, but the production of some 
 animal, shall the infinite spectacle of subserviency, 
 proportion and harmony, which the universe presents, 
 impress no conviction of design or of a designing 
 cause ? Shall design cease to be deducible when once 
 we have ascended from the mysterious operations of 
 animal instinct and human reason ? We know there is 
 designing intelligence in animals or men, only from 
 what they perform. We call them intelligent, only 
 because they act as if they were so. This is our only 
 evidence. If they were destitute of interior faculties, 
 
NATURAL THEOLOGY. V 
 
 they would still preserve the same outward appear- 
 ance. It is only, in any case, the existence of intelli- 
 gent acts that proves the existence of an intelligent 
 principle. And shall the work evince the workman 
 in e very instance but where the work is an exhibition 
 of infinite contrivance ? Must he be pronounced in- 
 telligent, who has written a book concerning the won- 
 ders of nature, and those wonders themselves not be 
 equal to sustain a similar conclusion ? What incredi- 
 ble blindness, to have suggested such a presumptuous 
 absurdity ! 
 
 T. If we should see the most superb palace in the 
 world, or the most magnificent production of human 
 art, should we not be delighted and amazed ? Why 
 then, are we not daily and hourly filled with raptu- 
 rous emotions, in contemplating that infinitely nobler 
 spectacle which is continually open to our inspection ? 
 
 A, '' The miracles of nature are exposed to our 
 eye, (as a celebrated French writer beautifully ex- 
 presses it), long before we have reason enough to de- 
 rive any light from them. If we entered the world, 
 with the same reason which a spectator carries with 
 him to an opera, the first time he enters a theatre, — 
 and if the curtain of the universe, if we may so term 
 it, were to be rapidly drawn up, struck with the gran- 
 deur of every thing which we saw, and all the obvi- 
 ous contrivances exhibited, we should not be capable 
 of refusing our homage to the Eternal Power, which 
 had prepared for us such a spectacle." But we do 
 not think of marvelling at objects we have seen for 
 
10 INTRODUCTION. 
 
 SO many years, or we think of them less, because 
 they have so often been before us. 
 
 T. Is this an argument in favor of those studies 
 which are adapted to awaken an attention to the 
 works of God ? 
 
 A. It is. We ought, if possible, to be always ex- 
 tending our acquaintance with the wonders with 
 which we are surrounded, which proclaim an all-wise 
 and beneficent Creator, so that we may pause and 
 suspend our thoughts, and feel more sensibly the 
 demonstrations of Providence, by observing them con- 
 tinually displayed in some new form. 
 
 T. It is for this reason, in part, we shall particu- 
 larly examine the human structure, which has not 
 probably been much attended to by most of you. But 
 I intended to ask you, whether it is requisite to the 
 evidence of design, that we should at once perceive 
 the architect himself? 
 
 A. By no means. I do not require to see the ma- 
 ker of a machine, to be convinced that a maker was 
 originally employed in the construction. If I should 
 find a palace in a desolate wild — with not a human 
 being to be seen, this would not lead me to suppose 
 that it never had an architect. It does not, therefore 
 weaken the demonstration of a creative Intelligence, 
 that the Architect of the universe is unseen. In 
 truth, when I come to reflect, I am sensible I never 
 beheld any architect, in reality, — not even a human 
 one. The outward form, which is all I ever perceiv- 
 ed is not the architect. The real architect is the 
 thinking, contriving mind ; and this was never seen 
 
NATURAL THEOLOGY. 11 
 
 by any human being. I could not, therefore, expect 
 to behold the Author of the universe, when I never 
 beheld the author of any other production. 
 
 T. This was the thought of Soci^ates. Does it 
 lessen the proof of an Infinite Intelligence, that we do 
 not understand every part of the universe, and that 
 many events are mysterious ? 
 
 A. Far from it. There are many productions of 
 human skill, which the inventors only can explain. 
 The wisest conduct of the parent often appears mys- 
 lirious to the child. We cannot wonder, therefore, 
 if the ways of Infinite Wisdom are frequently inscru- 
 table. 
 
 T. Can you mention any religious advantage, 
 which young persons particularly may be expected to 
 derive from this study ? 
 
 A. Every religious impression is most important 
 in early life. Our admiration of outward objects 
 should be directed into a devout channel at that pe- 
 riod, when they strike our senses the most powerfully. 
 Happy, if we are not then deficient in any know-^ 
 ledge which may enable us to perceive in every thing 
 around us, the proofs of divine wisdom and benefi- 
 cence, and lead us to view the beauties of nature with 
 perpetual reference to their Author. 
 
 T. Has this study any recommendation as a use- 
 ful exercise to the mind ? 
 
 A. The study of uses and designs in nature, must 
 conduce to a habit of careful observation and just rea- 
 soning, — and thereby promote one of the most impor- 
 tant objects of education, in that way in which the 
 
12 INTRODUCTION. 
 
 young would be most likely to be interested in the 
 pursuit. 
 
 T. For this purpose, which seems the more use- 
 ful, general contemplation of what is beautiful and 
 sublime in the works of nature, or examining carefully 
 into particular instances of design ? 
 
 A. To gain clear and distinct impressions, it is 
 necessary to inspect single examples minutely, and 
 to fix our attention upon the details of divine wisdom 
 and goodness. 
 
 T. What example most directly invites our ncv 
 tice ? 
 
 A. That example we have in ourselves, seems 
 most immediately our concern. Every part of the 
 universe may be equally curious, but none can be so 
 interesting to us, as our own frame. Whatever we 
 may know of the wisdom displayed in our own strue- 
 ture, how frequent are the occasions which remind us 
 of it ! We cannot but feel the most sensibly that 
 care which is manifested for our own benefit. Not a 
 child could be indifferent to an instance of divine 
 goodness, immediately concerning himself We need 
 not be anatomists, but we certainly ought to possess 
 some general knowledge of those exhibitions of Al- 
 mighty power and skill which have the most intimate 
 claims upon our regard, 
 
 T. What you are to describe, is only a general 
 outline of our wonderful machine. The object is not 
 to teach you a system of anatomy, but merely to no- 
 tice some of the leading marks of design in the hu- 
 man frame, so fearfully and wonderfully made. I 
 
NATURAL THEOLOGY. 13 
 
 hope they may lead you to a more realizing sense of 
 the Being around us, and dispose you to study with 
 more attention that still higher revelation of himself, 
 with which he has privileged us in his holy word. 
 Though we shall speak only of particular instances of 
 design, it is not because there are not innumerable 
 others equally deserving our notice ; the object mere- 
 ly being, to select a sufficient variety of examples 
 that may be easily understood, and to present them 
 in some order which may assist your recollection. 
 You may begin with what has been called the noblest 
 part of the human structure. 
 
 THE HEAD. 
 
 A. The head holds the first rank of all the visible 
 parts of the body. 
 
 T. Principally, because it contains the brain. — 
 You are aware how important the brain is, and that 
 the least injury may occasion the loss of the senses, 
 and be followed by fatal consequences. What do 
 you remember upon this subject ? 
 
 A. The brain is considered as the seat of sen- 
 sation, to which the impressions of all the nerves 
 are transmitted; the more immiediate residence of the 
 living principle ; and the organ with which Provi- 
 dence has mysteriously connected the exhibition of 
 
 B 
 
14 
 
 HEAir, 
 
 sensitive and intellectual powers. How it is the in-* 
 strument of such important uses, we are wholly un- 
 able to explain. No anatomical examination has 
 led to the least discovery. It is sufficient that, while 
 it is the most important organ of the animal system, 
 we see a corresponding care in several natural provi- 
 sions, to protect it from injury, and to preserve its 
 delicate texture from the least derangement. 
 
 JB. You observed that the exhibition of sensitive 
 and intellectual powers is mysteriously connected with 
 the brain. Did you mean that the mind itself is only 
 a certain property or quality of the animal brain ? 
 
 A. No. Only that certain injuries to the brain 
 seem to disturb the senses, and to produce insanity or 
 stupidity. So one^s sense of seeing would be impaired 
 or destroyed, to appearance, if his spectacles were 
 smoked or broken ; though the real difficulty would 
 be, not that the faculty of vision itself was injured, but 
 only the instrument by which that faculty is enabled to 
 shew itself, was rendered incapable of performing its 
 duty. Thus it may be, in the present appearance. 
 The brain is the instrument of the mind ; and when 
 the instrument is affected, the mind, to all appear- 
 ance, is affected too. But then, it is easy to show 
 bow it may be only appearance. 
 
 B. I believe I understand you. 
 
 T. I am happy you do in so few words ; for I do 
 not wish you to enter upon any metaphysical specu- 
 lations at present. We will reserve these for another 
 opportunity. I want you now to confine yourselves 
 to the consideration of the wisdom and goodness of 
 
NATURAL THEOLOGY. 
 
 15 
 
 the all-bountiful Creator, as manifested in the visible 
 frame, and in those things which are subjected to the 
 notice of our senses. You was speaking of the deli- 
 cate textare of the brain, and what striking instances 
 of care may be seen in the provisions which are made 
 for its preservation and security. 
 
 B. First, I wish you would give me some idea of 
 this organ, 
 
 A, It is a soft substance filling the hollow of 
 the head, composed of various parts differing in tex- 
 ture and figure, but unknown in their uses. — The 
 two principal divisions of this organ are called the 
 cerebrum and cerebellum ; the former occupying the 
 forward part of the head, and the latter, the poste- 
 rior or hinder part. What is called the spinal mar- 
 row, is a continuation of the brain into the hollow of 
 the back-bone, and is extended down through its 
 whole length. From this most of the nerves of the 
 body are given out. Gall and Spurzheim maintain 
 that the fore part of the brain has a particular con- 
 nexion with the intellectual powers ; and the back 
 part, with animal propensities. 
 
 T. This will suffice. We are now confining our 
 attention to exhibitions of design, and not going into 
 mere descriptions of parts. Taking for granted, what 
 it will require no argument to prove, the peculiar im- 
 portance of protecting the brain, on account of its 
 being the most delicate and essential organ in the ani- 
 mal frame, you may mention some of the principal 
 provisions, in which we are led to admire the displays 
 of ingenuity and contrivance, if we may so express it. 
 
16 HEAD. 
 
 for this purpose. They are very remarkable, and 
 you may be somewhat particular. 
 
 A. Anatomists speak with admiration of the car- 
 pentry and architectural contrivances exhibited in the 
 head, for the security of the brain. In the first place, 
 the skull is a hollow bone. A carpenter cases a deli- 
 cate article in a close, firm, solid box. It is the more 
 remarkable in the skull, because a bony case is not 
 the covering which is generally adopted in the body. 
 All the great cavities of the system are principally 
 sacs, formed chiefly by skins or membranes. But the 
 one which encloses the brain is hewn out of a bone. 
 The heart, the lungs, the stomach, the bowels, are 
 not equally tender, and have no such security. We 
 can see the wisdom of this arrangement. But we 
 discover no natural reason for it, besides design. — 
 The brain requires a stronger protection. Its su- 
 preme delicacy and importance render such a protec- 
 tion necessary. But this is no cause tahy a more 
 solid case should surround it, except as we refer ta 
 the agency of an intelligent Contriver. 
 
 B. So the strength of the cover is proportioned 
 to the tenderness of the substance which is lodged 
 within it. 
 
 A. The brain is not only protected by a solid 
 case, but is enclosed in a case by itself. The heart 
 and lungs occupy one cavity together ; the liver, sto- 
 mach, spleen, intestines, are packed in another cavity 
 below it. They are not of so soft and delicate a con- 
 sistency as to be disturbed by each other's motions, 
 or a slight degree of compression. But the brain is 
 
NATURAL THEOLOGY. 
 
 17 
 
 of such exquisite tenderness, that it would be injured 
 by the least pressure of surrounding parts. The skill 
 of the architect is here displayed, in causing the 
 brain to occupy a separate apartment. 
 
 B. How striking when it is mentioned 1 and yet 
 I doubt whether one person in a milhon has ever 
 thought of the circumstance. 
 
 T. Perhaps not ; and yet, I presume, nothing is 
 more true, than, that if the brain had been placed in 
 the chest, or in any such situation as is assigned to 
 the other vital organs, the pressure upon this tender 
 substance would have been instantly fatal. Do you 
 think of any evidence of design in the form of the 
 head ? 
 
 A. Round vessels are the least liable to be bro- 
 ken, or pressed in. Thus — a thin watch-glass, be- 
 cause it is rounded up in the middle, will bear a very 
 hard push. A full cask may fall with impunity, 
 where a square box would be dashed to pieces. A 
 yery thin, globular flask or glass, corked and sent 
 down many fathoms into the sea, will resist the pres- 
 sure of water around it. where a square bottle, with 
 sides of almost any thickness, would be crushed to 
 atoms. The common egg-shell is another example 
 of the same class. What hard blows of the spoon or 
 knife are often required to penetrate this wonderful 
 defence, provided for the dormant life, or living prin- 
 ciple, contained within the egg ! * The arches of 
 bridges, the roofs of houses, the helmets of soldiers, 
 
 * Arnott 
 
 b2 
 
18 HEAD. 
 
 Sic. , are all constructed upon the same principle. 
 This is not only the general form of the case which 
 has to cover and protect the brain ; but, wonderful to 
 think, the head is most rounded precisely in those 
 places, where, in falling, it would be most likely to 
 strike the ground. These are, the middle of the fore- 
 head, the projecting part of the head behind, and the 
 upper portions upon each side, or those least protect- 
 ed by the shoulders. Anatomists also observe, that 
 just in those situations where a carpenter strength- 
 ens his roofs by braces, there the roof of the skull 
 will be found to be strengthened by strong ridges of 
 bone on the inside, which answer the same purpose. 
 
 B. Any one may perceive; that the round form of 
 the head is the most beautiful, but few, it is probable, 
 have ever thought of any other advantage. 
 
 T. But this is a small part of the wisdom dis- 
 pjayed in this wonderful structure. 
 
 A. The skull is a double case ; and may be com- 
 pared to two bowls, one within the other. The outer 
 bowl is a tough and woody kind of bone. The inner 
 bowl is of a much more hard and brittle texture : 
 anatomists give it the name of vitreous, from a Latin 
 word which signifies glass. What completes the con- 
 trivance, there lies between, a corky, spongy kind of 
 bone, anatomists call it the diploe, — and each of these 
 particulars has its advantage. Our kind Architect 
 seems to have contemplated several distinct securities 
 in this structure, which are made necessary by differ- 
 ent and not infrequent dangers to which we are expo^ 
 sed. It is readily seen, that one familiar danger is. 
 
NATURAL THEOLOOT. 19 
 
 that of the head being pierced through by any pene- 
 trating body, as a fork, a penknife, the corner of a 
 stone, &c. ; and hence the advantage of a hard and 
 glassy cover about the brain, capable of turning the 
 edge of any sharp or pointed instrument. But then, 
 a covering hard and glassy throughout would be sub- 
 ject to be chipped and cracked continually. Under 
 these circumstances, the double case is plainly the 
 true mechanical contrivance, that is, an inner bone 
 calculated to resist any cutting or pointed body, 
 — plated over with another, less subject to be scaled 
 or splintered by strokes upon the outside. Such is 
 tlie architectural contrivance exhibited in the skull. 
 
 B. Who could ever have supposed all this to 
 be accidental ! If a man's ingenuity were to be ex- 
 ercised in contriving a protection for the brain, it 
 is difficult to say how he could have obtained the 
 object better. It seems as though there could be no 
 danger now from any common accident, except the 
 brain might be hable to be jarred by blows or falls 
 occasionally. 
 
 T. These blows and falls, however, are apt not 
 to be very infrequent ; and the brain is so tender 
 and sensitive an organ, as might render even a jar a 
 very serious affair. A celebrated anatomist observes, 
 that a blow upon a man's head, by a body which shall 
 cause a vibration, (or jar), through the substance of 
 the brain, may more effectually deprive him of sense 
 and motion, than if an axe or a sword penetrated into 
 the substance of the brain itself. There is, in several 
 respects, a remarkable structure of the head, adapted 
 
20 HEAD. 
 
 to this very danger. In most of the instances, the 
 structure has reference to other advantages, but it is 
 suited in every one to the advantage of which we are 
 now speaking. What have you learned upon this 
 subject ? 
 
 A. The globe of the head is composed of ssveral 
 bones. They admit, at birth, of being easily separa- 
 ted ; and during youth and up to the period of man- 
 hood, the seams or joinings of the pieces are still loose. 
 Now, it is apparent that unless the union of the joints 
 of any vessel is absolutely solid, as much so as in any 
 other part, it must tend to prevent a ringing, or jar, 
 from extending through. Hence it is, that the slight- 
 est disunion in a piece of ware may be detected by a 
 stroke of the knuckle, which could not else be dis- 
 covered ; the flaw impedes the vibration, and this af- 
 fects the sound. There is reason to believe, that in 
 early childhood, especially during the lessons of walk- 
 ing, this is one cause why falls are borne with so 
 much impunity. (Arnott on the Elements of Phy- 
 sics.) But anatomists mention another security ; the 
 more curious, because it has so precise a resemblance 
 to a kind of precaution we adopt ourselves in similar 
 cases. The skull is lined within, like a soldier's steel 
 cap ; — one advantage of which lining to the soldier is, 
 that it diminishes the jar occasioned by the sword, 
 and which would be capable of bringing him to the 
 ground without any penetration by the weapon. The 
 effect may be seen in a wine glass, which will not 
 ring if we but touch our finger upon the cup. There is 
 the same principle of security in the bony case, which 
 
NATURAL THEOLOGY. SI 
 
 surrounds the brain, and which is termed by anato- 
 mists, cranium^ from a Greek word signifying a helmet, 
 
 B. So, without knowing it, we have made our 
 helmets to cover the head, upon the very principle 
 upon which the head itself is constructed. 
 
 T. Yes, and in another circumstance quite as cu- 
 rious as this. 
 
 A. The helmet is not only lined with leather, but 
 covered with hair^ which is said not to be intended for 
 an ornament merely, but is an essential part of the pro- 
 tection. It breaks the force of the blow, and lessens 
 the agitation of the metal. Nature has done the same. 
 The advantage of the hair is two-fold. It tends to 
 prevent any tremulous motion in the skull, upon the 
 principle of a coating ; — and besides, furnishes the 
 general benefit of a cushion for the head ; for which 
 it is eminently fitted, it being the very material of 
 which cushions are usually made, on account of its 
 particular excellence as a springy or elastic substance. 
 Such are some of the uses which the wisdom of na- 
 ture has contrived to unite with this beautiful orna- 
 ment. 
 
 B. It appears, then, that the greater abundance 
 of the hair, when we are young and heedless, is no 
 unimportant circumstance. 
 
 A. There is one practice with regard to children, 
 however, that would not seem to accord very well 
 with this provision of Providence, — I mean that of 
 rocking them to sleep. The violence with which this 
 mechanical anodyne is often applied by the impatient 
 nurse, argues no great sensibility, one would think, in 
 the brain of the infant. 
 
22 HEAD. 
 
 T. It is possible that the regularity of the motion, 
 like that of musical sounds, may have a lulling effect, 
 and, so far as this cause is concerned, no injury per- 
 haps may arise. But you may be aware, the prac- 
 tice is, after all, objectecfto by some medical writers. 
 They say, that sleeping should be purely natural in a 
 healthy infant, as it is in after life, and not induced 
 by the stupifying effects of any artificial means. 
 
 You spoke of the skull as composed of several 
 bones. Is there any thing remarkable in the manner 
 in which they are united ? 
 
 A. It is surprising, anatomists observe, to see how 
 the pieces are joined in the best possible mode for se- 
 curity. The edges, where the bones unite, are cut 
 into little teeth, in a sawlike manner, and interlock 
 closely with one another, so as to produce the firmest 
 joint. It resembles that strong mode of uniting which 
 is called the dovetail, — or, more exactly, it is the fox- 
 tail joint of the carpenter, which he always employs 
 for strong work, when the pieces are small. Anato- 
 mists call it a suture. It makes the crinkling lines 
 which may be noticed on the outside of a dry skull. 
 
 a, one of the sutures on the outer portion of the skull. 
 
NATURAL THEOLOGY. 23 
 
 B. Are there no other bones which are united in 
 this manner? 
 
 T. None ; it is only in the skull, that it would be 
 found useful. 
 
 B. It is not the nature, then, of bones, as such, 
 to grow into one another in this dovetail form, but it 
 is confined to the brain case. 
 
 T. And hence, no doubt, you considered the de^ 
 sign more conspicuous, that there should be an ex- 
 ception for a single instance, and the only instance in 
 which it is required. If you know what is meant by 
 a dovetail joint, you are aware it only prevents the 
 parts which are united, from being drawn asunder. 
 The form of the joint does not secure them from 
 being lifted up, or crowded in, out of their places. 
 The mechanical contrivance for this purpose, as a 
 carpenter would say, must be a rabbeting or lapping 
 of the edges. What do the anatomists tell you as to 
 this matter in regard to the head ? 
 
 A. That if a carpenter were to inspect this in- 
 genious work, he would be struck with observing that 
 every bone overlaps the adjoining bone at some 
 points, and at other points it is itself overlapped by 
 them ; so that it is literally impossible that any bone 
 should be driven in upon the brain without absolutely 
 breaking it, which requires a great degree of violence. 
 
 B. One must be quite a mechanic, I perceive^ 
 to understand this surprising structure. 
 
 A. Anatomists further invite attention to another 
 particular. The teeth, which form the sutures, ar« 
 said not to extend through, that is, the processes or 
 
24 HEAD. 
 
 juttings out between the bones, and by which they 
 are interlaced, are observable only upon the outer sur^ 
 face, which belongs to the tougher, woody bowl of 
 the skull. On the internal surface, the pieces are 
 laid together in a manner more nearly approaching a 
 smooth line. This mode of joining is called by anat- 
 omists, harmonia, or harmony. The same joint, and 
 the same name for it, are used by architects in mason- 
 ry. This is pronounced remarkable, because it is so 
 plain, that, while the superior toughness of the exter- 
 nal surface will better admit of uniting by a dovetail 
 edge, as carpenters do in their work, the brittle na- 
 ture of the inside is not so suitable for this species of 
 joint : " as if a workman in glass or marble," says Dr. 
 Bell, " were to enclose some precious thing, he would 
 smooth the surfaces and unite them by cement, be- 
 cause, even if he could succeed in indenting the line 
 of union, he knows that his material would chip off 
 on the slightest vibration." Such is the ingenious 
 and provident structure of the skull. 
 
 Fig. 2. 
 
 b, one of the joints upon the internal surface of the skull. 
 
 B. One would think anatomists must be the most 
 devout persons in the w^orld, when they know so 
 
NATURAL THEOLOGY. 
 
 25 
 
 much more than others, of the wisdom of the human 
 frame. 
 
 T, I Gould detain you much longer, however, up- 
 on this wonderful workmanship. 
 
 B, No particular can be uninteresting, where the 
 hand of a Divine Architect is seen. 
 
 T. Do you know the use of those iron pieces, in 
 the shape of the letter S, you will often see on the 
 outside of brick buildings ? 
 
 B. I presume they are connected with the beams 
 upon the inside, and serve to keep the walls from 
 spreading apart. 
 
 T. And you must be sensible, as the dome of the 
 head is composed of several bones, in case of a vio- 
 lent pressure or blow upon the top, some security 
 might be useful for the same purpose. It is said, that 
 when a man falls, so as to strike the crown of his 
 head upon the ground, if the skull yields, it yields in 
 the temples, or it spreads out at the bottom of the 
 dome ; just where any other dome would spur out, 
 should the roof be too heavy for the support. Now, 
 is there any architecture of the head, that manifests a 
 knowledge of this danger ? 
 
 A. Anatomists describe a remarkable structure 
 which evidently contemplated it : wonderful as it 
 may seem, there is a bone, called the sphenoid bone, 
 which runs across the bottom of the skull, and turns 
 up with a plate at each extremity, so as to overlap 
 the walls upon the outside. The plate, (see 5, in 
 Fig. 1.), is thin in the head, but stronger, compara- 
 c 
 
HEAD. 
 
 lively than that which is used for the security of a 
 brick wall. 
 
 B. There seems to be no species of contrivance 
 but what is exemplified about this admirable archi- 
 tecture — and the more remarkable in the present 
 case, as there can be no natural tendency in the pres- 
 sure of the avails of the head to create tie pieces upon 
 each side, but the reverse : as well might we say, 
 that the pressure of the dome of St. Paul's Church in 
 London, has made the double chain which encompas- 
 ses it around the bottom to hinder it from spreading. 
 
 T. And you are aware this is the very object we 
 have in view, to show a creative Intelligence by dis- 
 playing actual and original purpose and contrivance, 
 in our frame, such as can only be referred to design. 
 You may mention some other particulars respecting 
 this wonderful mechanism. 
 
 A. The head is lined with a thick, firm mem- 
 brane, called the dura mater, and this lining is also 
 lined with a thinner membrane termed the pia mateVy 
 — -pia, (from one of the meanings of the word), ten- 
 der, affectionate . 
 
 B. Then, there is a softer wrapper in contact 
 with the brain, and a firmer one upon the outside. 
 
 T. Precisely the same mode we adopt ourselves, 
 in packing a precious article of which we wish to be 
 very careful. 
 
 B. Excepting the danger of some great violence, 
 against which no security could avail, it does not seem 
 possible to conceive what more could have been done 
 
NATURAL THEOLOGY. 27 
 
 in this wonderful piece of mechanism, to fit it for the 
 purposes it has to answer. 
 
 T. There is, at least one happy circumstance 
 more, deserving to be mentioned, and that is one 
 which contributes to the safety of the brain, even 
 when the head is broken in. Can you describe it ? 
 
 A. The principal lining of the head, which anato- 
 mists call the dura mater, (dura, — hard and unyield- 
 ing, to signify its strength), is so substantial a mem- 
 brane, that when the skull is fractured, it is not easy 
 for the pieces to fall in. In this respect, it may be 
 compared to the skin upon the outside of an egg, 
 which we often see preserving the form of the egg en- 
 tire, >vhen the shell is broken in a thousand pieces. 
 But for this, the surgeon would rarely be able to raise 
 the fragments of a skull without fatal consequences to 
 the brain. This lining is found ^1^ in the spine, 
 which contains a continuation of the substance of the 
 brain. We discover no such lining in the hollows of 
 the other bones. They contain nothing which re- 
 quires it. 
 
 T. You spoke of the packing of the brain as re- 
 markable. There is another instance, more curious 
 still, of the same kind. 
 
 A. There is a place where the membranes that 
 enclose the brain suddenly turn inward, and divide it 
 into two parts, so as to prevent one part from pressing 
 upon the other. The partition takes place in a re- 
 markable situation. It is where that portion of the 
 brain called the cerebrum, and which occupies the for- 
 ward and upper part of the head, begins to descend 
 
28 HEAD. 
 
 upon the other portion, viz. the cerebellum, which 
 lies in the lower and hinder section of the box; the 
 consequence of which would be, that one would com- 
 press the other, if it w^ere not for the partition between. 
 In ravenous animals, whose brain is subject to violent 
 motions from leaping, he, the partition is said, for 
 the most part, to be nearly, or quite, of the consisten- 
 cy of bone. 
 
 Fig. 3. 
 
 a, the cerebrum, b, the partition, or falx, separating the two 
 lobes or divisions of the brain, c, the cerebellum. 
 
 B. What an astonishing resemblance to art ! We 
 often see boxes containing a variety of precious wares, 
 parted off in this manner, where one must not be per- 
 mitted to be crowded by the others around it. There 
 seems to be no ingenuity but what is exemplified in 
 the construction of this wonderful case. 
 
 T. Is the head the same from infancy to old age ? 
 
 A. The changes are exceedingly remarkable. At 
 birth, the bones are said not to be locked together at 
 all. They are separated by membranous or skinny 
 spaces between them, so that they can overlap each 
 
NATURAL THEOLOOr. 29 
 
 Other considerably, and suffer the head to be reduced 
 in size. Besides this, there is another difference. 
 As we advance into dechning life, the whole skull be- 
 comes more like one uniform bone, when our own 
 care and our usual aversion to personal exposures, 
 render the securities of nature of less importance to 
 us. "The alteration in the substance of the bones, 
 and more particularly in the skull," says a most dis- 
 tinguished modern anatomist, " is marvellously order- 
 ed to follow the changes in the mind of the creature, 
 from the heedlessness of childhood to the caution of 
 age, and even to the helplessness of superanuation." 
 
 B There seems to be no end to the wonders of 
 this curious box. Who would have thought of the 
 skull's changing its structure and texture to suit dif- 
 ferent periods of life ! We have only to lift our hand 
 to our heads to be persuaded of a Divine Architect. 
 
 T. Can we trace any particular wisdom in the 
 different form of the head in different parts ? 
 
 A. The strongest form is at the back. Here the 
 head is the most rounded. Here also the skull is 
 particularly thick ; and besides both these provisions, 
 there are strong ridges of bone upon the inside, which 
 render it incapable, or nearly so, of any crack. It is 
 by far the strongest part of the head. Now, what is 
 remarkable, it happens to be the most exposed part, 
 as to being liable to the heaviest blows, from fajling 
 backward. In short, here is that marked and distin- 
 guishing species of foresight, in which a distant danger 
 is taken into view ; that is, in which the structure of 
 the head is adapted to the accidents of the feet. 
 c2 
 
30 HEAD. 
 
 B. Now we can understand why what always 
 seems to be so dangerous should be attended with no 
 more injury, the falling of boys upon the ice, as if 
 they would sometimes beat their heads in. It is in- 
 deed a beautiful fact, that the part of our head which 
 cannot have the protection of our hands, when we 
 fall, should be particularly guarded by the make of 
 the head itself. 
 
 A. We further observe, in this wonderful combi- 
 nation of precautions, that the temple bones, which 
 are the thinnest part of the box, are placed directly 
 over the shoulders, which secure them in case of a 
 fall ; and, besides, are a little flattened in within the 
 general circle of the head, which preserves them still 
 further from any blow ; and what is again remarkable, 
 are composed, anatomists say, of the hardest bony 
 matter in the whole body. " Generally it is observ- 
 able," says Dr. Bell, " of the whole structure of the 
 head, that those parts which would be most apt to 
 strike the ground when a man falls are the strongest." 
 
 T. Anatomists speak of a* remarkable display of 
 design in regard to preserving the brain from the 
 pressure of the blood. 
 
 B. I can easily conceive of this danger. I have 
 frequently felt a disagreeable sensation after running 
 or stooping, as of a fulness or pressure in the head. 
 
 T. Apoplexy, the most fatal of all disorders in 
 the brain, and which is generally occasioned by the 
 bursting of a blood vessel, or the interruption of the 
 passage of the blood in this delicate organ, has been 
 known to be brought on by persons whose vessels 
 
NATURAL THEOLOGY. 31 
 
 happened to be more crowded, or more feeble than 
 common, bending the head down m the act of tying 
 a shoe or drawing on a boot. Children and tumblers, 
 being much in the habit of placing their bodies in all 
 positions, feel no inconvenience from having the head 
 downwards, because blood vessels always become 
 strong enough to bear the pressure to which they are 
 habitually exposed ; but to many old people ac- 
 customed to keep the head always upright, the 
 attempt to imitate such feats would be dangerous. 
 This will lead you to appreciate the remarkable pro- 
 vision to which I alluded. Can you describe it ? 
 
 A. The principal blood vessels which carry up 
 the blood into the brain, and about one tenth part of 
 the whole blood in the body, it is said, is thrown into 
 that organ, are so contrived, that the force of the 
 stream, and it is thrown with a smart stroke, owing to 
 the nearness of the heart, is principally spent against 
 the bone of the skull. The provision is this. The 
 main artery of the head makes a sudden turn in the 
 base of the skull, by which the force of the current 
 is broken, and then distributes itself over the brain ; 
 the consequence of which is, the discharge is made 
 against the bony walls of the skull. It is like a 
 stream of water from an engine, striking against the 
 side of a building, which being done, the water drips 
 down or diffuses itself without any considerable vio- 
 lence. In quadrupeds, the poshion of whose headsj„ 
 being nearly upon the same line with their heart, 
 exposes the blood to flow with more force into the 
 brain, the blood vessels, where they enter the skull, 
 
32 HEAD. 
 
 are previously divided into a number of little branch- 
 es, which, by multiplying the channels, diminishes the 
 rush of the stream. 
 
 B. I shall never feel a throb in the head again ^ 
 after any violent exertion, without thinking of these 
 admirable securities. 
 
 A. The principal vessels which bring the blood 
 back from the brain are also a curiosity of contri- 
 vance. What is extraordinary, they differ from all 
 other veins in the body which are used for returning 
 the blood to the heart. It is plain, the blood ought 
 to have the freest and easiest return possible from the 
 brain. Any obstruction would be followed by the 
 most serious consequences immediately. " There- 
 fore, it is one of those particulars which powerfully 
 aftect a contemplative mind, as proofs of a designing 
 intelligence," says a late eminent writer, (Arnott on 
 Physics), " that the chief channels which return the 
 blood from the head, are not common compressible 
 veins, (the common veins are skinny or membranous 
 tubes, easily pressed together), but they are what 
 anatomists call sinuses, or grooves in the bone itself, 
 with exceedingly strong membranous coverings, sup- 
 ported so powerfully, that the channels become in 
 strength little inferior to complete channels of bone." 
 
 T. There are many varieties adapted to the na- 
 ture and circumstances of different animals. The 
 head most nearly resembling the human is that of the 
 monkey ; but there are several respects in which the 
 similitude fails, as may be seen in treatises upon 
 comparative anatomy 
 
NATURAL THEOLOGY. 33 
 
 The head of the elephant is remarkable for con- 
 taining uncommonly large vacuities in the frontal 
 bone, which render the enormous mass of the skull 
 much lighter and more easy to be borne in proportion 
 to the bulk than that of many other animals. 
 
 THE SENSES 
 
 T. Besides the mechanism of the head, what 
 other marks of design are mentioned in this wonder- 
 ful structure ? 
 
 A. That it is the seat of the principal senses, 
 such as sight and hearing. We know not why they 
 should be situated here, or why the eye and the ear 
 are not on some lower part of the body ; except, as 
 having to take notice of distant objects, they require 
 the highest situation they can have, to enable them 
 the better to perform their duty. But this is no rea- 
 son for their having this situation, as we can see, only 
 as we take into view an Architect, who was aware of 
 the advantage. Again, the eye looks forward in the 
 same direction with the motions of the hands and 
 feet ; but for which circumstance, the eye would 
 have been of very little use to us ; and yet there was 
 a whole circle of positions around the head, in which 
 it might have been differently situated. Let a child 
 only reflect upon the inconvenience of having his 
 eyes upon the side of his head, as over his ears, for 
 
34 SENSES. 
 
 example ; that is, of being compelled to look in one 
 direction and walk in another. The senses of sight 
 and hearing are given us in pairs ; so that if one eye, 
 or one ear should fail us, the duplicate may still an- 
 swer our purpose. None of the senses are single. 
 None of them are confined to one solitary spot of the 
 body, so as to be made dependent upon the safety of 
 that particular spot. 
 
 T. Does not the same wise arrangement appear 
 in the situation of the other senses ? 
 
 A. The situation of each is adapted to its use. 
 The sense of smell, which makes us acquainted with 
 the presence of odors, of which the air is the vehicle, 
 is placed in a continual current of air ; that is, in the 
 nostrils. In this situation, it not only best enjoys 
 what is agreeable to it, but by thus occupying one of 
 the main passages of the breathy it is enabled to per- 
 form the important office of apprizing us of the en- 
 trance of any unwholesome effluvia into the lungs ; 
 air unfit for respiration being usually offensive to this 
 sense. As most substances are also distinguishable 
 by their odor as to their being fit or unsuitable for 
 food, especially, it is said, in dumb animals, it is 
 striking to observe that the position of the smell is 
 immediately over the passage where every thing 
 must enter that we eat. The sense of taste, discov- 
 ers the same evidence of design. We can assign no 
 reason why it is placed within the cavity of the 
 mouth, except, that to enjoy our food, the faculty of 
 tasting it must be situated where the food is broken ; 
 and^not only so, but where the food is received, and 
 
NATURAL TJSEOLOGY. 33 
 
 masticated ; that is, not over the mouth, but within 
 it. The sense of feehng completes this wonderful 
 arrangement, by having no particular situation assign- 
 ed to it. Being spread over every part, it warns us 
 of dangers of which we could not have been apprized 
 by our other senses. It would have been exceeding- 
 ly unfortunate, if we must have had to see every nail 
 and splinter before we could draw back from a dan- 
 gerous puncture ; or could only know we were 
 scorching up, by observing the smoke. We can offer 
 no natural explanation why this particular sense 
 happens to be extended over the whole body. The 
 eye can perform its duty from one little spot in the 
 head ; and why the sense of feeling should not have 
 been confined to the head also, we can only answer, 
 because it is a sense which cannot perceive at a dis- 
 tance, but must be present at every part, where its 
 office is required. 
 
 T. You might have added another fact respecting 
 feeling, or, more properly speaking, the touch ; that 
 it is thi3 most nice and delicate, where we have the 
 most occasion for its use, viz. in the ends of the fin- 
 gers ; though it is said to be more delicate in the tip 
 of the tongue. 
 
 B. Is it not stated that there are more nerves, in 
 proportion, in the fingers, than in most other parts of 
 the body ? and we use the sense of touch more in 
 this part also, which must tend by practice to render 
 it more perfect. 
 
 T. The mechanism of touch exists in perfection 
 in the ball of the finger. But whatever the reason 
 
36 SENSES. 
 
 may be of the superior delicacy of the power in this 
 part — and there are several reasons, the fact is a 
 happy one, especially for blind persons. No doubt 
 you have heard of many curious instances. 
 
 A. The blind have been said to detect a joint 
 by the finger, which others were unable to discover 
 with the eye. It is mentioned, they are now learn- 
 ing to read print merely by feeling the indentations 
 made upon the paper by the types. 
 
 B. Have they not also been said to feel colors ? 
 though this seems incredible. 
 
 T. As every color requires a different substance 
 to produce it, it is only supposing every coloring 
 matter to be different in the shape or arrangement of 
 the particles of which it is composed, to account for 
 an extreme delicacy of touch being able to distin- 
 guish it. You have spoken of the touch as becom- 
 ing improved, when other senses are wanting. Is 
 this compensating providence confined to the touch ? 
 
 A. It extends to all the senses. It has been 
 observed of persons who have been deprived of any 
 particular sense, that peculiar power and delicacy 
 seem bestowed on those which remain. Thus, blind 
 persons are not only often distinguished by the ex- 
 quisiteness of their touch ; but, the deaf and dumb, 
 who gain all their knowledge through the eye, are 
 remarkable for the keenness with which they make 
 use of this channel of observation. 
 
 B. I should think one of the most extraordinary 
 instances, if we may judge from recent accounts, 
 might now be found in our own country. It is men- 
 
NATURAL THEOLOGY. 37 
 
 tioned that there is a pupil in the Hartford Asylum, 
 who is entirely deaf, dumb, and blind, and her touch 
 and smell are so exceedingly heightened, especially 
 the latter, that it seems to have acquired the proper- 
 ties of a new sense, and to transcend even the sagacity 
 of a spaniel. At her first reception into the Asylum, 
 she immediately busied herself in quietly exploring 
 the size of the apartments, and the height of the 
 stair cases ; she even knelt and smelled fo the 
 thresholds ; and, now, as if by the union of a myste- 
 rious geometry with a powerful memory, never makes 
 a false step upon a flight of stairs or enters a wrong 
 door, or mistakes her seat at the table. Her simple 
 wardrobe is systematically arranged, and it is impos- 
 sible to displace a single article in her drawers without 
 her perceiving and restoring it. She executes the 
 most beautiful work ; she gathers the first flowers 
 with a delight bordering on transport. Without ever 
 having been sick herself, she so readily comprehends 
 the efficacy and benevolence of the medical profession, 
 that she has been known, upon a physician placing her 
 finger upon her pulse — to lead him immediately to 
 the chamber of one of the pupils whose absence by 
 sickness she had niysteriously detected. She distin- 
 guishes the return of the Sabbath — and appears sa- 
 credly to observe it, as those intimately acquainted 
 with her habits assert.* 
 
 T. And all this merely by the aid of two senses, 
 the touch and the smell ! What a comment upon the 
 
 * Mrs. Sigourney's very interesting account in the Juvenile 
 Miscellany. 
 
38 
 
 SENSES. 
 
 inward powers of man, when they can accomplish so 
 much with so little external intercourse, or percep- 
 tion. But speaking of the sense of feeling, are not 
 many parts of the body so exposed to be chafed and 
 worn away by severe rubbing, as must be apt to ren- 
 der the delicacy of this sense very painful to us ? 
 
 A. There was an evident foresight of this very 
 difficulty ; and it is curious to see how it has been 
 provided against. The sailor covers his ropes with 
 leather where he knows they will be likely to be 
 frayed. He always carries leather to sea with him 
 for this purpose. But this is nothing to what nature 
 has done. We may notice her contrivance upon the 
 bottom of the heel. It is the scale or crust we there 
 observe, and which is produced altogether by the con- 
 stant rubbing and pressing of the foot in walking, as 
 infants have no such cases upon their heels. We see 
 the same, or what resembles it, in the hands, and 
 wherever the skin is subjected to hard usage. By 
 being tender of the part for a short time, the case dis- 
 appears, and the skin returns to its ordinary state. 
 The leather comes upon the rope, of its own accord, 
 and gradually goes off, as it ceases to be wanted. 
 
 B, What a happy provision, especially for the 
 poor laborer! The rock is made to give him his 
 gloves. 
 
 T. Are there any remarkable varieties in animals, 
 with respect to the senses ? 
 
 A. It is observable that in the fish the organs of 
 smell are placed on the outside, at the extremity of 
 the muzzle, so as to receive impressions from the 
 
NATURAL THEOLOGY. 39 
 
 water, as the fish swims forward. It is also noticed 
 that the animals which have the sense of smelling in 
 the greatest perfection, are those which live by hunt- 
 ing, and .have occasion to trace their prey to the 
 greatest distance. 
 
 THE EYE. 
 
 T. What evidences of design may be discovered 
 in the eye ? 
 
 A. If any instrument may be said to exhibit con- 
 trivance, it is this admirable and beautiful little organ. 
 The eye is made almost precisely upon the model 
 of a telescope or spying-glass. There is the same 
 general kind of mechanism ; the same principles ap- 
 plied ; the same knowledge discovered of the laws 
 and properties of light ; only the construction of the 
 eye is much more ingeniously adapted to these laws, 
 and parts for the same purposes are contrived to 
 much better effect, than in any other telescope. In 
 short, an eye taken to pieces, for this is necessary to 
 form any idea of it, is such a wonderful spying-glass, 
 that it has taught the best telescope makers how to 
 improve their own instruments. It discovers several 
 curious contrivances, of which the most skilful artists 
 had never dreamt. Some of them are so wonderful, 
 ^ that we shall probably never be able to imitate them ; 
 
40 Et^E. 
 
 but they will always leave the eye, it is likely, ther 
 most finished instrument of the kind, that ever was or 
 ever can be made. 
 
 B. One must be quite learned, then, about teles- 
 copes to understand the construction of the eye. 
 
 T. The more learned the better ; but every one 
 must understand enough for the present purpose. If 
 you have ever pulled out the tube of a spying-glass, 
 and unscrewed the joints, you know it contains seve- 
 ral little rounded glasses ; — ^it is these glasses that 
 make the telescope. The eye is just such another 
 instrument ; so that when we are espying, we may 
 say there are two telescopes, — ^the one in our hand, 
 and the other in our head ; and the use of the one 
 without; is to assist the one which is within in seeing 
 further. They are both constructed on the same 
 principles. You may describe the eye. 
 
 A. The principal parts of the eye are, as in other 
 telescopes, rounded glasses, or substances which re- 
 semble them, and which answer the same end, though 
 they are not of glass. They are all situated in the 
 ball. The front of the ball is covered with a transpa- 
 rent skin, which is termed the cornea, from a Latin 
 word signifying horn, because it has a certain resem- 
 blance to a very delicate shaving of this substance. 
 It is a little thicker in the middle than towards the 
 edges, and has in a degree the same effect as a mag- 
 nifying or telescope glass. Next to this is a fluid, 
 commonly called the aqueous humor, and which will 
 run out when the eye is pricked. It derives its name 
 from the Latin word for water. It fills the forward 
 
Katural theology. 
 
 41 
 
 part of the ball, and is kept in a round form by the 
 shape of the eye. It serves the same purpose as the 
 magnifying glasses which are used in telescopes ; it 
 being well known that a round drop of water will 
 magnify like a piece of glass of the same shape. Next, 
 and immediately behind this water glass, if we may 
 so term it, we come to a curtain, called the irisy 
 stretching entirely across from side to side, with a 
 small round hole in the middle. This hole is named 
 the pupil. We see the same in a spying-glass ; it 
 being found to increase the clearness of the sight, 
 when the light passes through a little aperture. In 
 telescopes the contrivance is what the instrument ma- 
 kers call the field. This is a plate of brass inside the 
 tube, perforated in the middle with a small round 
 hole directly in a line with the centre of the glass be- 
 fore which the field is placed. This contrivance is 
 found to improve the instrument by not permitting 
 
 Fig. 4^5. 
 
 A telescope glass, I, with its curtain before it, a a, in which there 
 is an aperture at the centre : being a precise imitation of the 
 eye, where the same parts are indicated ia the Figure by the 
 same letters ; viz. 1, the principal glass of the eye, called the 
 chrystaline ; a a, the iris, with the pupil in the middle. 
 D 2 
 
42 
 
 UTE. 
 
 the passage of any light but what enters about mid- 
 way of the glasses. To this structure there is a won- 
 derful resemblance in the natural telescope ; the iris 
 being the field ; and the pupil answering to the little 
 aperture in the field, it being exactly before the cen- 
 tre of the principal glass of the eye.. (See Fig. 4 
 and 5.) 
 
 But the hole in the eye, which is called the pupil, 
 is made to answer another purpose. It enlarges or 
 contracts, to suit the quantity of light, s6 that in a 
 bright sun too much light may not be admitted into 
 the eye ; which would be painful and injurious. If 
 we examine the eye of a person by bringing up a can-' 
 die, we shall see this opening diminish, as the light in- 
 creases ; or, if we darken the eye with our hands, and 
 suddenly remove them, we shall notice the same eflfect. 
 The curtain, which we term the iris, has, in different 
 persons, different colors around the pupil in front, ma- 
 king that painted circle we observe in the middle of 
 the eye ; in some people, black, in others, blue, he. 
 It has been remarked, that it is generally either light 
 or dark, according to the color of the hair. Behind 
 the pupil is situated the next glass of the eye, called 
 the chrysialine humor.* This is still more rounded ; 
 and is of a gristly substance, but perfectly clear and 
 transparent ; and is the most powerful glass in the 
 
 • A small portion of the aqueous humor is situated between th» 
 pupil and the chrystaline ; but this is not of essential impor- 
 tance in the present description. One use of this mtermediate 
 water is supposed to be, to moisten the iris, and enable this 
 important curtain to perform its office with more ease. 
 
NATURAL THBOLOGT. 43 
 
 eye. It is the little ball we take out of a fish's eye. 
 Immediately behind the chrystaline, is situated the 
 last glass of the eye, something in the shape of the 
 water glass in front, and is called the vitreous humor y 
 . from its resemblance to melted glass. The light, by 
 passing through all these glasses, so to term them, is 
 drawn to a little round spot, such as is made by a 
 burning-glass ; and this spot contains an image of the 
 object at which we look. Thus, if we hold up a 
 a spectacle or telescope glass between the window 
 and a sheet of paper, there will be a small bright spot 
 on the paper, and in that spot we shall see the image 
 of the window and the objects on the outside. The 
 glasses in the eye do the same ; and it is so contrived, 
 that the image falls exactly upon the delicate sub- 
 stance of the nerve which is spread out on tlie back 
 part of the eye, like a sheet of paper, and is called 
 the retina. If the skin on the hinder part of an ox's 
 eye be carefully removed, and the eye be held up to 
 the window, the images of objects in the street will 
 be seen distinctly painted on the back, where the re- 
 tina is situated. If any injury happen to the eye to 
 prevent the image from being formed, we are unable 
 to see. This, therefore, is the demonstration of de- 
 sign, — nature requiring an image for the purposes of 
 vision, has furnished an instrument perfectly adapted 
 to produce it ; a mechanical and complicated instru- 
 ment ; in sh(5rt, a literal telescope. 
 
 T. You spoke of the roundness of the eyeball. 
 Is it a perfect sphere ? 
 
44 
 
 SYB. 
 
 A. Not exactly. The front projects beyond the 
 general curvature. The effect is, the compass of 
 our vision is enlarged, and we can see further around 
 us, than if this part of the eye were not so protu- 
 berant. 
 
 B. What a multiplicity of provisions for the per- 
 fection of this beautiful and noble organ. 
 
 Fii 
 
 6. 
 
 e, aqueous humor, t, t, iris, o, pupil, d, chrystaline humor. 
 e, e, vitreous humor. a, a, rays of light crossing at the pu- 
 pil, and passing from the object a, a, to form the image on 
 the retina, a, a. f, optic nerve. 
 
 T. In speaking of the pupil, do you remember 
 what is stated as to the contrivance by which it is al- 
 ways kept in a round form ? 
 
 A. The constant exactness of the circle, notwith- 
 standing its changing its dimensions almost every mo- 
 ment, has .been always mentioned as a curious phe- 
 nomenon. No artist would find it easy to imitate this 
 contrivance. It has been supposed to be effected by 
 means of fibres or threads in the iris, so arranged with 
 reference to the central opening as to enlarge or con- 
 tract it like a purse ; though some anatomists are not 
 entirely satisfied how it is produced. They say the 
 
NATURAL THEOLOGY. 45 
 
 apparatus is so delicate and obscure that they cannot 
 decide upon its true character. 
 
 B. There must be some wonderful mechanism 
 about this aperture, the membrane of the iris must be 
 exceedingly sensitive to feel every change of the light 
 so immediately. 
 
 T. Why, here is another remakable fact, which 
 shews what amazing design runs through every part 
 of our structure. The changes in the pupil are to 
 benefit the retina, so that too much light may never 
 fell upon this tender substance. Now, as the retina 
 is the part to be benefitted, it is evidently desirable 
 that this should have the management of the pupil by 
 which the light is admitted. Had the curtain, or iris, 
 which contains the pupil contracted or enlarged the 
 opening by any sensibility which it has itself to the 
 light ; and this, till recently, has always been suppo- 
 sed to be the fact ; it is easy to see, that the tender- 
 ness of the retina might sometimes be greater or less, 
 than that of the curtain, (for it often varies), — and 
 would consequently be liable to suffer. Do you re- 
 collect any notice of this particular ? 
 
 A. It is said, by a late valuable writer,* to have 
 been ascertained by a very delicate experiment, that 
 if a ray of light be admitted into the eye in such a di- 
 rection as only to strike upon the iris or curtain, with- 
 out passing through the pupil — the pupil is not affect- 
 ed — no change of the aperture takes place ; but if it 
 enter the pupil, and thereby fall upon the retina, a 
 contraction immediately ensues. The. sensibiUty is 
 
 Pr. J. Ware, of Boston. 
 
46 EYE. 
 
 lodged not in the coritr acting part, but in another 
 part at a distance from it, for whose benefit the pro- 
 vision is designed. 
 
 B. It seems like one holding a screen which he 
 spreads or folds according to the wish of the person 
 whom he is protecting. No wonder it should be said, 
 the eye is a cure for atheism. We can suppose the 
 Almighty Creator could have enabled us to see with- 
 out all this machinery ; — but then, observing the ma- 
 chinery makes us more sensible of an actual Architect 
 in our frame. Still there appears to be one difference 
 between the eye and a telescope. If we look with a 
 telescope or spying-glass at a far object, as a vessel 
 upon the ocean, and then turn it to a person standing 
 by us at a few feet distant, we find we are now un- 
 able to see : but it is not so with the eye. Our sight 
 is not affected by any moderate change of distance. 
 What can be the reason ? 
 
 A. The reason is, and it is a new reason for ad- 
 miring the eye, that the spying-glass requires to be al- 
 tered, or fixed anew, before we can see a near object, 
 after looking at a distant one. Now this is done in 
 our eyes in an instant. In the spying-glass, we have 
 to pull out or thrust in a tube, so as to change the 
 distances of the glasses from one another, — or else 
 put in glasses of a different form. There is exactly 
 the same or a similar contri«vance in the eye. It is 
 difficult to describe it, it is so exceedingly curious, 
 But the effect is to enable the eye to suit its glasses 
 imraedialely to the different distances at which we 
 have occasion to look. 
 
NATURAL THEOLOGY. 47 
 
 B. It must be very perfect ; when we think how 
 quickly we can glance from one object to another, — 
 from surveying a sta?- to threading a needle. Still, 
 one would hardly have thought there was occasion 
 for all this machinery to enable the eye to do what it 
 appears to do in such cases, without any exertion ; — 
 and yet we can feel there is some apparatus at work 
 about our eyes, which seems to strain when we try to 
 look at an object close up to our faces, or at a very 
 unusual distance. 
 
 T. We have had a wonderful account of this or- 
 gan of the eye. But it is worthy a more minute de- 
 scription still. Its Divine Architect has introduced 
 contrivance upon contrivance, to render it the most 
 surprising telescope that was ever made. You may 
 go on with the description. 
 
 A. In telescopes it is necessary, and the discove- 
 ry is a somewhat late one, that the glasses should not 
 all be of one Icind of glass. Though most persons 
 are not in the habit of observing it, for it requires a 
 close attention, yet it is a truth with regard to every 
 telescope or magnifying glass, let it be formed of what 
 kind of glass it may, that it produces a rainbow ap- 
 pearance, or variety of colors about the little bright 
 spot or image where the light is collected. The rea- 
 son is this. " Light consists of different colored parts, 
 as Sir Isaac Newton discovered, some of which are 
 sooner collected by the glass, or more quickly drawn 
 to a little circle or image, than the others ; the conse- 
 quence of which is, when we hold up a burning-glass 
 or a telescope glass to the sun, the lights of different 
 
48 , EYE. 
 
 colors come to a point at different distances, and thus 
 create several circles, which makes a confusion. — 
 This was long found to make our telescopes imper- 
 fect, insomuch that it became necessary to make them 
 of reflectors or mirrors, and not of magnifying glas- 
 ses.*' But it has since been discovered, that if cer- 
 tain different kinds of glass, viz. flint glass and crown 
 glass, be placed together, so as to make a compound 
 magnifier, they serve to correct this defect. No rain- 
 bow is then produced. The improvement was intro- 
 duced not many years ago, in the celebrated teles- 
 copes known by the name of the Dolland telescopes. 
 But it is now ascertained, that the whole discovery 
 was well understood in the first telescope that ever 
 was constructed ; that is, in the eye. " It is found 
 that the different natural magnifiers of the eye are 
 combined upon a principle of the same kind." What 
 is more curious, thirty years after the time of Dolland, 
 a discovery was made by Dr. Blair, of Edinburgh, of 
 the greatly superior effect which combinations of fluid 
 and solid magnifiers have in correcting the imperfec- 
 tion ; and, most wonderful to think, when the eye is 
 examined, we find it contains solid and fluid magni- 
 fiers combined, acting naturally upon the same prin- 
 ciple which was thus recently found out by many in- 
 genious mechanical and chemical experiments. 
 
 B. One can hardly understand so much contri- 
 vance ; and yet it is beautiful as an evidence of de- 
 sign, and of an all-^jise Author, to find so much ma- 
 chinery in the eye, which shews the deepest acquaint- 
 ance with philosophical principles ; and to know that 
 
NATUBAL THEOLOGY. 
 
 49 
 
 the most celebrated artists have been forestalled and 
 outdone in what they supposed to be their own dis- 
 coveries and inventions. 
 
 T. There is another imperfection to which teles- 
 cope glasses are subject, and it has occasioned much 
 trouble and perplexity to the makers of these instru- 
 ments, but which affords new reason to admire the 
 h^nd of a perfect Artist in the construction of the 
 eye. 
 
 A. The difficulty has been, and it still remains 
 an insuperable difficulty, to make any magnifying glas- 
 ses, of the usual shape, act equally in every part. 
 The rays of light which pass through near the edge^ 
 will come to a focus, and form the little circle or im- 
 age, before those do which pass through the middle 
 of the glass ; — and so in proportion, at every inter- 
 mediate point. This makes numerous images ; and 
 although the different images are all sufficiently uni- 
 ted in one, for common purposes, yet, in glasses 
 intended for very distinct and accurate vision, it 
 has been found a very serious inconvenience. It 
 is found to be owing to the form of the glass, as the 
 form commonly is, which is that of a spectacle glass. 
 This form, it can be demonstrated, has less power at 
 the middle than at the more distant parts of the glass. 
 The attempt has been made, by changing the form, to 
 get rid of this difficulty ; and by great skill and atten* 
 tion, the improvement perhaps can be effected. Sir 
 Isaac Newton doubted whether it ever could be per- 
 fectly effected. But there is another remedy, though 
 
50 EYE. 
 
 beyond our ingenuity, it is probable ; and that is, as 
 the difficulty is owing to the form of the glass not 
 being so powerful in the middle, to increase the power 
 by making the middle of a more powerful kind of 
 glass, that is, of a more dense or solid kind. Wonderful 
 as it may seem, this contrivance is actually adopted in 
 the eye. The chrystaline, or principal glass of the 
 eye, is of greater solidity toward the middle. The 
 solidity increases from the edge to the centre. For 
 the glasses in a telescope to possess the same advan- 
 tage, it would be necessary they should each be made 
 of innumerable kinds of glass, gradually increasing in 
 solidity, from the edge to the middle of the glass. 
 This can hardly be done ; and hence the eye exhibits 
 an example of telescopical knowledge and ingenuity 
 which stands unrivalled. 
 
 B. This is all new information. If one could not 
 understand a word, it would be delightful to hear of 
 all this curious philosophy in our eyes ; because it 
 seems a signal illustration of divine wisdom and in- 
 telligence. 
 
 T. Are there any other respects in which this 
 wonderful organ displays the same sort of superiority ? 
 
 A. Yes, there is one no less remarkable. The 
 light which comes from an object into a spying-glass 
 or telescope, and by which the object is seen, does 
 not all reach the eye. A part of it is thrown back 
 from every glass in the instrument; and this is no 
 benefit but a disadvantage. But there is no remedy. 
 It is a settled principle with respect to light, that 
 when it passes from the air into a telescope, some of 
 
 .^.. 
 
NATURAL THEOLOGY. 51 
 
 it will be reflected, or thrown back in this manner ; 
 — or, more generally, the principle is this : when 
 light passes from air into glass, or from water into 
 glass — or from any such substance into another of a 
 different kind, though most of it will be transmitted, a 
 portion will be stopped at the surface, and be thrown 
 back or reflected. The glistening upon the surface 
 of a bright window is this effect. The light, in pass- 
 iHg from the air into the window, undergoes a reflec- 
 tion, in some measure, at the surface of the glass. It 
 is because the air and the glass are not the same sub- 
 stance. There is the same glistening upon the sur- 
 face of the ocean ; but there is none within the ocean 
 itself; because the water continues the same. How 
 it should fail to be quite considerable in the eye, 
 when there are no less than three different kinds of 
 substances through which the light must pass, has 
 been a question. It is stated that there is a most 
 curious and provident contrivance which meets this 
 difficulty. Notwithstanding the three substances in 
 the eye differ, generally speaking, like air, water and 
 glass, though the difference is less ; yet, where they 
 touch, and where the light passes from one to the 
 other, and where it must be reflected, if reflected at 
 all, they are nearly of the same substance. The 
 middle one, which is the chrystalline, and which is 
 quite solid toward the centre, diminishes its consis- 
 tency on its two opposite sides, to approach that of 
 the vitreous behind, and that of the aqueous before. 
 Thus, there is less chance for the light to be thrown 
 back or reflected from the glasses ; the principle of 
 the reflection requiring that the light, in passing from 
 
52 
 
 EYE. 
 
 one substance to another, should find a sudden differ- 
 ence. Such is the structure of the eye ; discovering 
 such perfect acquaintance with some of the most 
 curious properties of light ; and uniting philosophi- 
 cal contrivances, various, as they are admirable and 
 inimitable. 
 
 T. Speaking of the reflection of the light, do you 
 understand why the inside of a spying-glass is always 
 painted hlack around the glasses ? 
 
 A. To prevent the glistening of that portion of 
 the light which strikes against the sides of the tube. 
 There is a similar provision in our eyes. The inside 
 lining on the back part of the eye, called the choroid 
 coat, is blackened over with a substance termed the 
 pigmentum nigrum, hlack pigment, or paint. In 
 many animals, such as cats, owls, &;c., this paint is of 
 a bright color which reflects the light. The precise 
 object of the difference seems yet to be a subject of 
 inquiry. Some have conjectured that it enables the 
 animal to see better in the dark. It has, no doubt, 
 some design. It is ascertained in our own eyes, that 
 if from any cause the black pigment happens to be 
 wanting, the sight is injuriously affected. The sin- 
 gular persons called 'Albinos, from a Latin word sig- 
 nifying white, have no such pigment in their eyes ; 
 and it is found their vision is extremely imperfect in 
 a bright light ; so that they can scarcely see how to 
 direct themselves. 
 
NATURAL THEOLOGY. 
 
 53 
 
 Securities of the Eye. 
 
 T. In a tekscope it is necessary the glasses 
 should be preserved from the least scratch, dust, or 
 injury ; how is this managed in the] eye ? 
 
 A. The principal securhy is the eye-lid. This 
 active little shutter seems almost animated with a 
 sense of the important office assigned it. It closes 
 immediately, as if of its own accord, whenever any 
 thing approaches very near the eye. Every person 
 is sensible how hard it is to keep from winking in 
 such a case, even though challenged to do it if he 
 can. It seems to be one of the natural securities 
 provided originally by the all-wise Architect ; for we 
 discover the same in infants. It is not, therefore, the 
 result of habit or experience. It is a further mark of 
 design, that the shutter shoald be made in two parts ; 
 the eye, of course, is sooner covered by dividing the 
 duty between them ; nor is this the only advantage. 
 The middle of the ball, being the spot where the 
 light enters, by having two shutters, the one above 
 and the other below, we are enabled to see, and to 
 cover our eyes at the same time : that is, to cover 
 them, all but a little space ; whereas with a single 
 lid, one half of the front must always have been open 
 and exposed, to enable us to see at all. 
 
 B. What perfect mechanism ! How admirable 
 the whole art of divine wisdjm in the formation of 
 this fine organ ! 
 
 T, Very perfect for a shutter ; but still a dehcate 
 place for a shutter to be employed. You may judge 
 £ 2 
 
54 KTE. 
 
 of this, by touching your eye with your finger, or let- 
 ting the nib of a pen fly into it. What is to prevent 
 a constant suffering, with a shutter rubbing directly 
 and immediately upon the eye at every wink ? 
 
 A. A wonderful apparatus evinces how distinctly 
 this danger has been foreseen. An oily liquor is 
 continually oozing out from a row of little glands 
 resembling bags and situated at the roots of the eye- 
 lashes. There is also another wash : this is thinner 
 and in much greater quantity. We call it the tears. 
 The tears help to lubricate the eye ; and, besides, 
 answer another purpose. The lids could not have 
 squeezed out the dust ; a water was necessary to 
 carry it off. It is found also that when the ball hap- 
 pens to become dry, it loses its clearness and trans- 
 parency in some degree. Now with reference to 
 hoth these uses, it is admirable to notice how many 
 little circumstancs are made to increase the tears, 
 when the tears are the most wanted. Thus our eyes 
 water the most in the wind, which would otherwise 
 immediately dry them ; — and any offending body 
 falling into the eye produces the same effect. 
 
 B. The flow of the tears is an exquisite contri- 
 vance ; but what becomes of the wash ? It cannot 
 remain pure for a long time. 
 
 A. To complete this wonderful structure, there is 
 a provision for this also. There is situated at the 
 inner corner of the eye, an outlet which empties into 
 the nose, and by which the tears are discharged. It 
 is the same contrivance as the dripping hole to a 
 water trough, which continually carries off the water, 
 
NATURAL THEOLOGY. 55 
 
 and permits a constant renewal from the fountain. 
 
 Fig, 7. 
 
 A reservoir for water — exhibiting the fountain and outlet. 
 
 This outlet in the eye is furnished with two small ori- 
 fices, which the anatomists call puncta lachryma lia, 
 or tear holes. The water is conducted along within 
 the eye by a structure of the lids, not very easy to 
 describe ; but entirely mechanical, and the effect of 
 which is to incline the tears to run easily to the open- 
 ing. The winking of the lids is a part of the contri- 
 vance ; it presses the water toward the place of dis- 
 charge ; and hence the quickened motion of the eye- 
 lids when persons are endeavoring to conceal a tear. 
 
 B. This now explains the disease we sometimes 
 see in those whose tears run down in a constant stream 
 upon the outside of their faces. 
 
 T. Yes, and a very serious disease it is : the t)ri- 
 fices are closed up. Many persons have submitted to 
 the painful operation which is rarely successful, of 
 having the outlet opened anew by artificial means. 
 We see, therefore, the kind intention which provided 
 the opening in the first instance. " It is easily per- 
 ceived the eye must want moisture ; but could the 
 
56 EYE. 
 
 want of the eye generate the gland which produces 
 the tear, or bore the hole by which it is discharged, 
 — a hole through a bone ! " 
 
 1, the lachrymal gland, the source of the tears. &, the channels 
 or ducts which lead the tears from the lachrymal gland into 
 the eye. c, c, the puncta lachrymalia, or tear holes, which 
 conduct the tears into the outlet or lachrymal sac, by which 
 they are discharged into the nostril. It will here be noticed, 
 that the reservoir precisely resembles the eye, not only as to 
 having an outlet, but as to the fountain being in both cases 
 elevated above the place of reception. Owing to this circum- 
 stance, the tears more readily enter the eye. It will also be 
 observed, that in each instance the source is at one corner, 
 and the outlet at the opposite. This is evidently beneficial to 
 the eye ; as hereby the tears must pass the entire length of 
 the organ, and lubricate its whole surface, before they are 
 discharged. 
 
 Are there any other respects in which we discover 
 intentional contrivance for the security of the eye ? 
 
 A. It is lodged in a strong, bony socket, called 
 the orbit, composed of several bones, the upper of 
 
NATURAL THEOLOGY. 57 
 
 which is arched and sustains a portion of the brain. 
 In the back part of the socket, a large quantity of 
 fat is deposited, on which the ball rests as upon a 
 cushion, so as to enjoy easy motion in every direc- 
 tion ; and it is because this cushion is apt to be wast- 
 ed by disease, the eye usually appears sunk after a 
 long sickness. The eyebrows are described by Socra- 
 tes as a thatched pent house, to prevent the sweat and 
 moisture from running down into the eye. The eye- 
 lashes are another additional protection. 
 
 B. What is most striking, there is such a number 
 of these protections, the lid, the socket, the brows, 
 the lashes, the tears, displaying an extraordinary de- 
 gree of care and solicitude, proportionate to the im- 
 portance and delicacy of the organ ; — ^not one of 
 which, moreover, as we can see, has the least tenden- 
 cy to produce another, and therein presenting the 
 more evidence of design. But notwithstanding the 
 perfection of this wonderful mechanism, has it not 
 been said that there is a certain spot on the part 
 where the image is formed which is insensible ? 
 
 A. It is supposed to be the spot where the nerve 
 enters the eye ; but the manner in which the defect is 
 remedied is a new proof of the wisdom with which our 
 eyes are made. There is the same little blind spot, 
 it is said, in both eyes. But it is stated, that if one 
 eye should happen to be insensible, the same difficulty 
 cannot occur in the other at the same time ; or both 
 spots cannot blind us at once ; so that we shall never 
 be conscious there is any such spot, when both eyes 
 are open. The contrivance is this. The nerve, 
 
58 EYE. 
 
 which has to enter somewhere to make the retina on 
 which the image is received, does not enter exactly 
 at the centre, but a Uttle towards the nose. Now, 
 mathematicians say, that owing to this slight vari- 
 ation from the centre, it can be calculated to a de- 
 monstration, that the little circle or image in the eye, 
 can never fall on both insensible parts at the same 
 time. The experiment is easily tried. Place two 
 small circles of white paper upon a dark colored wall, 
 at the height of the eye, and at the distance of nearly 
 two feet from each , other. If the spectator, at a 
 proper distance, shuts his right eye, and looks with the 
 left directly at the paper on his right hand, he will 
 not see the left hand paper, although the objects 
 around it are visible. But let both eyes be opened, 
 and it will appear distinctly. 
 
 Varieties of Eyes. 
 
 T. Are the eyes of all animals constructed alike ? 
 
 A. The differences are very numerous and strik- 
 ing. Besides the evidence of design in the structure 
 of the eye itself, we have a further proof of the exist- 
 ence of wisdom in its formation, and that it is no blind 
 production of nature, when we observe that the sense 
 of seeing is not given to all animals in the same way, 
 but that the organs are varied as is best adapted to 
 the different kinds of animals. The varieties extend 
 to almost every part of the eye. Fishes have a re- 
 
NATURAL. THEOLOGY. 59 
 
 markable peculiarity in their eyes, which is required 
 by the nature of the element they inhabit. It is a 
 fact with respect to light, that whenever it passes 
 directly from water into a magnifying glass, the glass 
 must be more rounded, in order to produce the same 
 effect as would take place, if the glass was surrounded 
 by air. Agreeably, it is found, that the chief mag- 
 nifier in the eyes of those animals which inhabit the 
 water, is far more round than in those of land animals. 
 The structure which produces the tears is wanting in 
 fishes. The water in which they live renders the 
 tears unnecessary. The eel, which has to work its 
 way in the mud amid the hardest and roughest sub- 
 stances, is provided with a horny, transparent case 
 for the eye, which protects the part without ob- 
 structing the vision. The frog has a similar security. 
 
 B. What, pray, can the frog want of a pair of 
 spectacles ? 
 
 T. To defend the eyes from the sharp edges of 
 the spear-grass, Sic, among which these little crea- 
 tures have to live. But you may give the descrip- 
 tion. 
 
 A. As the progressive motion of this animal is 
 not by walking but by leaping, — ^if his eyes were not 
 provided with such a case, he must either shut them, 
 and so leap blindfolded, or, by leaving them open, 
 must run the risk of having the front part of the eye 
 cut, pricked, or otherwise injured ; but this mem- 
 brane, like a kind of spectacle, covers the eye without 
 taking away the sight ; and, as soon as the occasion 
 
60 EYE. 
 
 Ceases, the animal withdraws it into a little cell, where 
 it rests till its use is again required. 
 
 B. A pair of goggles, and a pocket to keep them 
 in ! If this be not design, it would be difficult to say 
 what would be so. 
 
 A. Many birds have a similar security. The eye 
 of the mole, which has to work its way under ground, 
 is singularly suited to the habits of this animal. Ev- 
 ery thing about the construction of this little creature, 
 seems to decide that it must dig the earth and live in 
 the ground. The form of the feet, for example, is 
 like that of so many shovels. Unless the eye, there- 
 fore, were adapted to such a mode of life, the situ- 
 ation of the animal would be truly unfortunate. This 
 adaptation exists. ^' The eyes of this little pioneer 
 are scarcely larger than the head of a pin, and are, 
 besides, sunk down very deeply into the skull. To 
 shelter them still farther, the eyebrows, if so they 
 may be termed, not only cover the eyes, but present 
 a considerably large prominence, or cushion to any 
 sharp or protruding substance which might push 
 against them. In short, the eye of a mole looks like 
 a pin hole in a piece of velvet." 
 
 The eyes of animals which catch their food by 
 night, such as the cat, owl, &tc., possess a faculty not 
 given to those of other species, viz., of closing the 
 pupil entirely. By this means, they are able to favor 
 their eyes in a bright sun, and avoid the glare which 
 must needs be painful to such eyes as theirs, which 
 have to be made very delicate and sensitive to see in 
 the dark ; besides, the glare must injure the delicacy 
 
NATURAL THEOLOGY. 6| 
 
 of the eye. Dr. Herschell, the celebrated astrono- 
 mer, while pursuing his nicest observations, was in 
 the habit, it is said, of practising upon this very prin- 
 ciple ; that is, of covering his eyes in the day, to in- 
 crease the sharpness of his sight in the night. 
 
 It has been often noticed, that the pupil of a cat's 
 eye, and that of several other animals, is not round, 
 like our own, — but it is in the form of a long slit, 
 reaching from the top to the bottom of the eye. It 
 is made in two parts, like the sliding doors of a mod- 
 ern parlor, so as to admit of a close joint to exclude 
 the daylight entirely ; or, of being wholly drawn 
 back, so as to leave no obstruction to the light, in 
 the dark places the animal loves to frequent. 
 
 T. Is the number of eyes the same in all ani- 
 mals? 
 
 A. The fly, the bee, and various insects, have 
 many eyes, or what is equivalent, set round on each 
 side of the head, though they are so united, as to re- 
 semble only two eyes at the first inspection. It re- 
 quires a microscope to see them, and the appearance 
 is extremely beautiful. Some insects, it is compu- 
 ted, have as many as several thousand eyes. 
 
 T. What design of Providence do you here dis*- 
 cover ? 
 
 A. As these insects have no motion of the eye, 
 they would labor under an evident disadvantage, un- 
 less their organ of vision was a kind of multiplying 
 glass, looking in every quarter, and catching every 
 object. 
 
62 
 
 EYE. 
 
 Fig. 9. 
 
 The head of an eel ; the skin is represented as turned back. — 
 m, TO, the transparent horny coverings of the eyes, which 
 being situated in the skin, are separated with it. 
 
 T. Upon a review of the construction and prop- 
 erties of the eye, what general reflection is suggest 
 ed as to the proofs of intelligence and wisdom it ex- 
 hibits ? 
 
 A. That it embraces so many distinct and inde- 
 pendent contrivances, not one of which has any tend- 
 ency, as was observed, to produce another; that 
 there is such a variety of provisions, dissimilar in 
 their nature, and which nothing but design could have 
 brought together ; giving great complexity to the in- 
 strument, but each adding a distinct excellence. The 
 greater the variety, and the more intricate the struc- 
 ture, the more evident the design. The eye sees^ it 
 may be said, and this is design enough. But because 
 the eye sees, it does not follow, there should be so 
 many provisions to enable it to see so perfectly ; — 
 
NATURAL THEOLOGY. Oo 
 
 it does not follow, there should be a curious mechan- 
 ism by which it can adjust its glasses, to enjoy the 
 advantage of a microscope and a telescope at the 
 same time ; — it does not follow, there should be the 
 contrivance of a perforated curtain, by which the 
 quantity of light admitted or excluded is tempered to 
 the delicate sensibility of the eye ; — it does not fol- 
 low, that the glasses should be of different substances, 
 or so constructed as to contain the highest improve- 
 ment of the modern telescope, in regard to prevent- 
 ing a certain rainbow appearance, which would ob- 
 scure the sight ; — it does not follow, there must be an 
 increasing consistency of the principal glass, from the 
 edge to the middle, remedying another inconvenience 
 to which all the telescope glasses of the same form 
 that ever were or can be made are unavoidably sub- 
 ject ; — it does not follow, that the principal glass must 
 also lessen its consistency from the centre to the 
 sides, so as to agree and make, as it were, one sub- 
 stance with the glasses between which it is situated, 
 thus avoiding another difficulty which in every other 
 telescope, of a similar nature, is perfectly incurable ; 
 — it does not follow, that the nerve of the eye, which 
 receives the image, should enter a little out of the 
 centre towards the nose, so as to prevent any image 
 from being lost in both eyes at the same time ; — and, 
 when we have a perfect eye, it does not follow, it 
 should be so well protected, and preserved so con- 
 stantly bright and fit for use ; that it should be lodged 
 in a bony cavern for its more perfect protection from 
 all outward violence, with a soft, flexible veil hang- 
 
64 EYE. 
 
 ing before it, susceptible of the quickest motions, to 
 be interposed upon every occasion, — and furnished 
 with an exquisite contrivance to cleanse and moisten 
 it, and a conduit to conduct off the liquid which has 
 been employed ; and even then, there is no natural 
 consequence by which it follows, that it must be fit- 
 ted with such a complete set of muscles to turn it in 
 every direction, and give us the most perfect com- 
 mand over the organ. 
 
 T. After having examined the most wonderful 
 instrument with which we are acquainted, and with 
 which no work of human ingenuity admits of compa- 
 rison, it is quite superfluous to extend our research to 
 other parts of the animal structure, for any purpose 
 of religious conviction. There is no occasion for 
 multiplying examples of contrivance, to prove a con- 
 triver. The organ of hearing is more obscure in 
 some parts of its construction ; but as it exhibits a 
 new description of philosophical principles, quite as 
 admirably applied, you may give some account of 
 this structure. What traces of a Divine Intelligence 
 do you discover in the ear 1 
 
 B. Before leaving the eye, there might have 
 been remarked one design, more interesting, perhaps, 
 than any which has been named. 
 
 T. And what may that be ? 
 
 B, The pleasures and use of sight seem to be the 
 most delightful proofs of a designing Providence, in- 
 dependent of any particular construction of the organ 
 itself Without this sense, a large part of our capaci- 
 ties would be lost to us. Our sensibility to the plea- 
 
NATURAL THEOLOGY. 65 
 
 sures of vision, one of the most constant and exqui 
 site we possess, would have been given us in vain. 
 Not only so, our intellectual capacities would have 
 been in a great measure useless ; for how little could 
 we know without the eye! In this view, the mere 
 existence of this little telescope, without any refer- 
 ence to its structure, does of itself conduct our minds 
 to an intelligent and beneficent Author. It forms the 
 same evidence of design, as the artist exhibits, who, 
 when he has made a machine, provides the spring, 
 the pendulum, or the weight, which is necessary to 
 put it in motion. 
 
 T. Very true ; there can be no more decisive evi- 
 dence of intention and wisdom, as to this wonderful 
 organ, than that it is not only a most exquisite piece of 
 workmanship in itself considered, but that when the 
 instrument is made, it is perfectly adapted to our 
 wants, and is necessary for the exercise and improve- 
 ment of our noblest faculties. 
 
 B. The ^ame thought is beautifully suggested by 
 Addison. " Our sight is the most perfect and most 
 delightful af all our senses ; it fills the mind with the 
 largest variety of ideas, converses with its object at 
 the greatest distance, and continues the longest in ac- 
 tion without being tired or satiated with its proper en- 
 joyments." 
 
 T. Sturms, after giving a minute description of 
 the eye, has expressed in his devout and animated 
 manner, a reflection upon its uses, which is very 
 pertinent in a religious view, and which you may 
 quote. 
 
 f2 
 
66 EYE. 
 
 A. " I praise thee, O Lord God, for having form- 
 ed my eye in so wonderful a manner ! I have not 
 hitherto considered the gift of sight as I should have 
 done, that is, as a masterpiece of thy hands, and as a 
 convincing proofs that even the most minute parts of 
 my body are the works of God and not of blind 
 chance. Pardon me, O wise and Almighty Creator ! 
 if, while I have used my eyes, I have not thought of 
 thee with the warmest gratitude. May I employ 
 them in examining thy word and works ; and wheth- 
 er I contemplate the heavens or the earth ; my- 
 self or the sacred volume ; may I be induced to bless 
 and praise thy wonderful goodness. When I behold 
 the miseries of many of my fellow-creatures, let not 
 my eye refuse them tears, nor my heart be shut up 
 to compassion ; thus may I fulfil the views of thy 
 goodness, and through Jesus Christ be worthy of thy 
 approbation." 
 
 T. A similar reflection might with but too much 
 propriety, be extended to all the powers with which 
 our Creator has endowed us ; — that we do not devote 
 them, as we should do, to his service. I trust, that, 
 in contemplating new proofs of his power and wisdom, 
 we may be excited to a stronger disposition to honor 
 him with " our bodies and spirits which are his." — 
 You may proceed to the next description. 
 
NATURAL THEOLOGY. 67 
 
 THE EAR. 
 
 A. Although the construction of the ear, anato- 
 mists observe, is not so well understood as that of the 
 eye, it exhibits in its general form, both internal and 
 external, a mechanism which is admirably contrived 
 for the reception of sound. It is fitted with a fleshy 
 rim on the outside, which is called the concha, or 
 trumpet, — because it spreads like the mouth of a 
 trumpet, around the hole of the ear where the sound 
 enters the head ; and the use of the trumpet is, to 
 collect the sound into this passage. Ear trumpets 
 are constructed upon this principle, for the benefit of 
 persons who are hard of hearing ; — only the spreading 
 part is much larger than it is in the ear. The artifi- 
 cial invention-sho\\B the wisdom of the natural msivu- 
 ment, and how evidently it was designed with reference 
 to the uses it answers in the animal structure. The ris- 
 ings and furrrows which give the rim of the ear such an 
 irregular appearance are said to perfect the trumpet, 
 by directing the sound more completely into the hole. 
 In those persons who have not flattened their ears 
 down upon their heads by tight bandages, but suffer- 
 ed the rim to take its natural position, it slightly in- 
 clines forward, like holding our hand back of the ear, 
 when we wish to hear more distinctly. This has 
 been mentioned as remarkably the case in savages, 
 whose hearing is uncommonly delicate. Many ani- 
 mals, especially the little, timid, and helpless rabbit, 
 have the trumpet much larger and more perfect than 
 
68 EAR. 
 
 in the human species ; and are also capable of turning 
 it to any quarter from which they may be anxious to 
 collect the slightest sound. '^ This motion of the 
 ear," says Richerand, " is lost, or more properly 
 speaking, not employed in the human ear, as long as 
 the organ continues in a perfect state ; but when its 
 more internal mechanism is injured, and ceases to act 
 upon the sound as usual, the external ear resumes the 
 office to which it was originally adapted, and by a de- 
 gree of motion and erection assists the hearing." A 
 little distance within the hole of the ear, we come first 
 to a membrane stretching entirely across from side to 
 side, forming a complete partition. It may be com- 
 pared to the pelt or head of a drum ; and is common- 
 ly called the drum of the ear ; anatomists term it the 
 membrane of the tympanum, which means, skin of a 
 drum. Behind this partition, we come to an open 
 space usually termed the barrel of the ear, — the ana- 
 tomical expression is tympanum, from a Latin word 
 signifying a drum. What is most curious to observe, 
 is the little clock work within this barrel. It is a con- 
 trivance of four extremely minute bones, one of 
 which is fastened by the end into the main drum 
 head, that is, the membrane of the tympanum, and 
 the others, connecting along from the opposite end of 
 this bone, stretch up into the barrel of the ear, till the 
 last stops upon another drum head, drawn over the 
 mouth of another barrel, which is deeply situated in 
 the solid bone of the skull, and which contains a wat- 
 ery matter, and also the nerve of the ear, floating in 
 this liquid. The second barrel, so to terra it, is called 
 
NATURAL THEOLOGY. 69 
 
 the labyrinth, from its being so winding and full of 
 passages. There are some other little internal cavi- 
 ties and passages ; one especially leading into the 
 main barrel with a membrane over it, called the fo- 
 ramen rotundum, or round opening ; another, called 
 the Eustachian tube. This is about the whole of the 
 machinery. 
 
 B. There seems to be an abundance of it, but 
 rather complicated and obscure. 
 
 A. The waves of the air, and what is called 
 sound, is attributed to a certain peculiar motion in 
 the air, resembling waves, produced by the sounding 
 body, are supposed to enter the ear and strike upon 
 the principal drum head, or membrane of the tympa- 
 num, like a drum-stick, — and to be communicated, by 
 means of the little bones and the air on the inside to 
 the other drum heads ; these, in their turn, are pre- 
 sumed to operate upon the fluid contained in the bar- 
 rels they cover, so as to affect the delicate filaments 
 of the nerves which float about in this fluid — and 
 thereby produce the sensation of hearing. It is 
 one continued transmission through a complicated 
 chain of conductors most mechanically fitted up for 
 the purpose. The sound is also supposed to be car- 
 ried to the nerve, in some degree, through the solid 
 walls of the ear ; just, as in a stick of timber, we 
 can hear the slightest tap upon one end, by holding 
 our ear to the other. 
 
 B. The little bones seem to be the most curious 
 part of the contrivance. 
 
70 EAE. 
 
 A. To look upon, anatomists say, they are more 
 like what we are accustomed to call machinery, than 
 almost any thing beside in animal bodies. It is, as if, 
 upon cutting open a drum, we should find a chain of 
 little rods hinging one upon another across the whole 
 length of the barrel from head to head. It has been 
 suggested, that they probably tighten or loosen the 
 drum heads, with which these bones communicate ; 
 just as the musician loosens or strains up the head of 
 his drum by means of the cords and leathers, which 
 we see on the outside. By stretching or loosening 
 the head, he strengthens or weakens his sounds ; and 
 the little bones are supposed by many anatomists, to 
 produce the same effect. 
 
 B. They make a tuning apparatus then, it seems, 
 for our ears. 
 
 T. Their chief use is generally conceived to be, 
 to conduct the sound from one drum head to the 
 other. Do you know that every drum has a hole in 
 the barrel ? and are you acquainted with the reason ? 
 
 B. It would seem necessary to admit the air into 
 the drum ; otherwise, the air would not be the same 
 on both sides of the drum head, and whichever should 
 press the most, — the external, or the internal air, — it 
 would crowd against the skin and be injurious to the 
 sound ; at least, I suppose it is for some such reason, 
 that the hole is made. 
 
 T. Why then are we not subject to some incon- 
 venience in the ear, when the barrel has no commu- 
 nication with the air by means of the external ear. on 
 account of the membrane of the tympanum, which 
 
NATURAL THEOLOGY. 71 
 
 Fig. 10. 
 
 a, the external ear, called the concha, or trumpet. 10, hol« 
 of the ear, slit open ; termed the meatus auditorius externus, 
 or outward passage of the ear. 9, membrane of the tym- 
 panum, stretching across the ear; or the main drum head of 
 the ear. It makes a complete partition at the bottom of the 
 hole of the ear. 1, 2, 3, 4, lines pointing to the four little 
 bones seen extending across the tympanum or drum, behind 
 the membrane of the tympanum, the last of the bones being 
 in the shape of a stirrup : and the lower end of the first bone 
 being inserted into the membrane of the tympanum. 6, en- 
 trance into the labyrinth, or back drum of the ear, having 
 a membrane over it on which the stirrup plays. 5, three 
 lines pointing to the semicircular canals, which form a part 
 of the labyrinth. 7, the cochlea or shell, so named from its 
 resemblance to a cockle, and forming a portion of the laby- 
 rinth. 8, the Eustachian tube, leading from the tympanum 
 or drum to the back part of the mouth. - 
 
 you know extends across and shuts up the passage, a 
 little within the entrance ? 
 
 jL. Though there is no communication in this di- 
 rection, there is another passage, called the Eusta- 
 
72 EAR. 
 
 chian tube, which is a slender pipe sufficient to 
 conduct the air, and which leads from the inside of 
 the barrel to the back part of the mouth. 
 
 B. How wonderful to notice the many particulars 
 wherein our own ingenuity has been anticipated in 
 the contrivances of nature ! 
 
 T. Do we discover any provision in the structure 
 of the ear, to guard against the dangers to which it is 
 exposed ? 
 
 A. The hairs which are placed at its entrance, 
 together with the cerumen or wax within the cavity, 
 prevent the introduction of foreign bodies, such, for 
 example, as grains of sand, dust, insects, &c. 
 
 B. Then it must be cruel to remove this hair, as 
 is practised upon some dumb creatures. 
 
 T. I presume you speak of the horse. The loss 
 of this protection no doubt occasions much suffering 
 to the poor animal. He has no means, like our- 
 selves, of removing obstructions from the ear; and 
 therefore should not be deprived of any natural 
 security. 
 
 B. I do not see but that the organ of hearing is 
 as admirably contrived as the eye, notwithstanding it 
 is said to be so obscure. Perhaps we may still say 
 of this organ, however, as of the eye, that the most 
 striking demonstration of a designing intelligence is 
 its relation and necessity to our other faculties. '' It 
 enables us to hold communion with our fellow crea- 
 tures, to inspire and exalt our understandings, by the 
 mutual interchange of ideas, and thus to increase the 
 circle not only of our physical but our moral relations. 
 
NATURAL THEOLOGY. 73 
 
 The charms of eloquence, the pleasure resulting from 
 the concord of sweet sounds, are other sources of 
 intellectual enjoyment, which contribute to place this 
 sense among the most delightful as well as the most 
 important we possess. Whoever has witnessed and 
 attentively observed the distressing effects arising 
 from a loss or diminution of its sensibility will readily 
 acknowledge that such deprivation throws us at a 
 distance from our fellow-creatures and in the present 
 state of society renders us more solitary beings, than 
 the loss of sight itself." One would therefore say, 
 the first manifestation of Providence in this admirable 
 organ relates to its importance. 
 
 T. No doubt, an All-wise Creator principally ap- 
 pears in such views of the subject as these. We 
 are to be most grateful for the uses and enjoyments 
 for which every part is fitted, rather ^han for the skill 
 displayed in the construction of the part itself. 
 These considerations should again induce us to adore 
 the ineffable wisdom and Vonderful Jgoodness which 
 our maker displays in every part of our frame. 
 They should make us more sensible of the value of 
 the organ by which we are enabled to enjoy the 
 benefits of speech, and to receive the various delight- 
 ful impressions which are imparted by sound. While 
 we reflect how much our happiness would be dimin- 
 ished, if we could not communicate our thoughts by 
 conversation ; how lamentable we should feel it, if 
 we were to be denied this medium of intercourse 
 with our friends ; it should teach us to value our own 
 
 G 
 
74 SPINE. 
 
 blessings, and to praise God who among his innu- 
 merable benefits has given us the power of hearing. 
 There is now another field we are to survey, which 
 will bring into view new occasions for admiration. 
 The head contains the organs by which the ^ body is 
 directed. We are to see the machinery by which 
 the motions are performed ; that is, the bones and 
 muscles generally, which are the active parts of the 
 body. You may describe the principal and most 
 important bone, — the one immediately connected 
 with the head. 
 
 THE SPINE. 
 
 A. The head rests upon a strong, upright, bony 
 column, which forms the centre of the back, and is 
 •ailed the spine, or back-bone. 
 
 B. 1 never could conceive why this should be 
 called a bone. We certainly bend it very easily, 
 and therefore it cannot be one continued, solid body, 
 like a bone. 
 
 T. It is a chain of joints of very admirable con- 
 struction, and this you will see. 
 
 A. Anatomists describe it as a wonderful speci- 
 men of mechanism. It has to answer several impor- 
 tant purposes most difficult to be united. A portion 
 of the most delicate substance of the brain, called th« 
 spinal marrow^ is continued down through the hoi- 
 
NATURAL THEOLOGY. / 75 
 
 low of this bone, resembling the pith in the stalk of 
 a plant. This substance is so exceedingly tender, 
 and vital, that the slightest wound, or even pressure, 
 would be productive of serious and probably fatal 
 consequences. It might seem, therefore, that in or- 
 der to secure it the more completely from any injury, 
 the case which contains it ought to be a firm and 
 unbending tube. Yet the spine must bend to admit 
 of the motions of the body. Any considerable bend- 
 ing in one particular spot, however, would press upon 
 the marrow within, and be highly dangerous. 
 
 The danger is happily avoided by the bone being 
 composed of a great number of little rings piled one 
 upon another, as many as twenty-four, which are 
 called the vertebrce, from a Latin word, which signi- 
 fies to turn. They admit of a great flexure through 
 the whole, without requiring each to bend but a very 
 little. Thus, stooping is not a sudden, hinge-like 
 motion in a single spot, like shutting a penknife ; but 
 is the united bending or curvature of several bones, 
 for a considerable extent upon the back, like bending 
 a piece of whale-bone. If the bend were entirely 
 at one place, a wrinkle or crease would be made in 
 the spinal marrow, such as we may see on the inside 
 of the joint of the finger, when we bend the finger 
 inward. No other bone in the body is so constructed. 
 No other requires it. 
 
 B. By no other requiring it, is meant, no doubt, 
 that no other bone which has to bend, contains the 
 same delicate contents. This is truly a wonderful 
 expression of design. The only bone in the body 
 
76 SPINE, 
 
 which bends with an elastic curve instead of a hinge, 
 is the only one where a hinge would be dangerous. 
 Every one knows that his back is composed of little 
 bones ; but few, probably, are aware how much wis- 
 dom it exhibits, and that their lives would have been 
 in danger every moment, upon any other construc- 
 tion. Still, it would seem that a bone composed of 
 so many little rings, must be very liable to be slipped 
 apart, especially, when we consider what violent mo- 
 tions we sometimes have occasion to make with it. 
 
 T. Do we discover any evidence of intentional 
 precaution against this accident ? 
 
 A. We behold a wonderful structure, having an 
 immediate respect to this very danger. The bone is 
 as skillfully secured, as the substance entrusted to it 
 is vital and teruier. It is as safe, as we might sup- 
 pose it dangerous. Notwithstanding all the sudden 
 and violent motions to which this part is subject, 
 there is no injury to the body perhaps which is more 
 infrequent than disuniting or displacing any of the 
 bones of the spine. Although the bones are in such 
 constant motion upon one another, the hollows of the 
 rings perfectly agree ; so that the hole in one bone 
 corresponds exactly with the holes in the two bones 
 contiguous to it — else it would produce a break in 
 the spinal marrow. They always form one close, un- 
 interrupted channel. Bend the spine as we please, 
 practise all the contortions upon it we can, not one of 
 the little bones can be made to project upon the inte- 
 rior cavity, so as to injure the smoothness of the bore. 
 Let an artist be requested to execute a similar piece 
 of work. Bespeak a hollow cane of twenty-four 
 
NATURAL THEOLOGY. 77 
 
 joints, to be used for the ordinary purposes of such 
 an instrument, and yet to inclose a most tender sub- 
 stance, exceedingly precious, to which it would be 
 fatal if a wrinkle should be produced in it at any one 
 of the flexures. No mechanic could probably be in- 
 duced to undertake so difficult a task. 
 
 T, And how is it done in the spine ? 
 
 A. The first contrivance is a firm bandage from 
 ring to ring. Besides this, there is a further secu- 
 rity ; and a more studied security, — one more care- 
 fully contrived, or more evidently evincing care, it 
 is impossible to imagine. The bones are not smooth 
 and regular: on each of them there are what anato- 
 mists term processes — projections or spurs, which 
 give them, at first view, quite a deformed appear- 
 ance, and such as we see in no other bone in the 
 body. Every one of these protuberances, or pro- 
 cesses upon the bone, is found, upon examination, 
 to be a check to some improper motion. What- 
 ever slip attempts to take place, it is supported by 
 the form of the bone. It is past the ingenuity of man 
 to dislocate the spine : that is to say, to find a mode 
 hy which he can elude the wisdom of the construc- 
 tion ; in which, by any pressure short of breaking the 
 parts, he can thrust one of the bones from between 
 its neighbors. " Let him take, for example, into his 
 hands, a piece of the clean picked bone of a hare's 
 back ; consisting, we will suppose, of three vertebrae. 
 He will find the middle bone of the three so implica- 
 ted, by means of its projections, or processes, with 
 the bone on each side of it, that no pressure which 
 g2 
 
78 
 
 SPINE. 
 
 he can use, will force it out of its place between 
 them. It will give way neither forward, nor back- 
 ward, nor on either side." 
 
 T. And what is most impressive, here, we have a 
 structure which cannot be interpreted as a natural 
 effect. The processes of the . spine are not naturally 
 produced by any motions — ^but they are checks to 
 hinder motion. When we endeavor to bend back- 
 ward too far — the tendency of this endeavor would 
 be to smooth away the joint, and suffer the motion to 
 be made : it would be any thing but that of forcing 
 out little spurs Xo prevent it. 
 
 This admirable structure, therefore, has but one 
 conceivable explanation, — that of an original design. 
 We observe securities introduced, where the natural 
 result would have been the very opposite. We see 
 the reverse of a natural cause. We see design, and 
 that is all we perceive. Truly may we say, how evi- 
 dent the indications of his agency, whose fingers have 
 fashioned us, and in whom we live, and move, and 
 have our being. 
 
 But you will not overlook another curiosity in this 
 wonderful part — the provision for turning the head. 
 
 A. The plan of the spine, upon which the head 
 is supported, forbids the turning of one bone upon 
 another. Its joints are hinges, confining to one mo- 
 tion, that of stooping and bending merely. We can- 
 not turn our breasts opposite to our feet. We see 
 the wisdom of this, if only on one account, — ^the 
 safety of the spinal marrow, which ought evidently 
 to be spared every unnecessary motion. This is the 
 principle of the spine through an extended series of 
 
NATURAL THEOLOGY. 7^ 
 
 more than twenty bones. But one exception was 
 necessary to enable the head to turn, by a motion of 
 its own, without always being at the trouble of turn- 
 ing the whole body. To admit of this, one solitary 
 deviation is introduced. One bone of the neck, which 
 is a part of the spine, is permitted to turn round, — 
 and only one. The construction is this. The head, 
 together with the first bone of the neck, forms a per- 
 fect swivel, like the head of a cane, made to twirl 
 round upon the staff. There is a notch in the first 
 bone which receives a pin that runs up into it from 
 the second, making what mechanics would call ^ pin, 
 or pivot joint. Upon this joint the head has a firm 
 and accurate motion within a certain extent on each 
 side, as far as is necessary. 
 
 B. Every part seems to be the most wonderful, 
 till we hear another described. Still, one might al- 
 most tremble to think of turning the neck, after what 
 anatomists say of the spinal marrow. 
 
 T. It is this which renders the mechanism truly 
 remarkable. There was plainly a choice of joints to 
 enable the head to turn. Now, anatomists invite our 
 attention to the singular safety of the joint by which 
 tliis motion is performed. 
 
 A. There are several joints which would have 
 permitted it. The bone which revolves might have 
 been fitted with a cavity to the head of the bone im- 
 mediately beneath. There are a number of these 
 joints in the body. They are called ball and socket 
 joints, in which the head of one bone is received into 
 a cup or socket in the other. There is such a joint 
 
80 SPINE. 
 
 in the neighborhood of the neck, at the shoulder 
 blade ; and no other kind is ever employed in the 
 body, for a revolving joint, except in the single in- 
 stance of the neck. They are all liable, however, to 
 flip in some degree, in the socket ; which, while of no 
 importance in any other situation, would have been 
 dangerous to the spinal marrow. A smart blow might 
 easily dislocate such a joint. But nothing can slip a 
 pin joint, short of breaking the pin. 
 
 B. I do not see how any atheist could ever have 
 been acquainted with his own structure. 
 
 T. Do you think of any striking resemblance to 
 the works of art, in the mechanism of the neck ? 
 
 A. When we bend the head downward, we make 
 use of the hinge joint, which is situated between the 
 head and the first vertebra of the neck. In moving the 
 head horizontally, that is, in turning it round on either 
 side, we make use of the pin joint, which lies immedi- 
 ately under the former, and plays between the first 
 bone of the neck and the second. The same two 
 kinds of joints, similarly situated, and exactly resem- 
 bling those of the human head, are employed in the 
 frame or mounting of a telescope. It is occasionally 
 requisite to move the telescope up and down, as when 
 we want to point it to a star which lies higher or lower 
 than another. It is also required, that it should be 
 able to take a circular motion, as when we want to re- 
 move it from one star and point it to another star, by 
 the side of it. For the first motion, there is a hinge 
 upon which the telescope plays up and down ; for the 
 next, there is an axis or pivot on which the hinge and 
 the telescope upon it turn round together. This is 
 
NATURAL THEOLOGY. 81 
 
 precisely the mechanism which is used in the motions 
 of the head ! 
 
 T. You can turn the telescope, however, entirely 
 round ; but you are aware, it is not the same with the 
 head. The head has only a certain degree of motion 
 from side to side ; and this is confined to a very small 
 compass, though sufficient for the purpose ; — suffi- 
 cient, that is, with the motion of the eyes, which 
 nearly completes the circle. But f )r this limitation 
 of this motion, I need not tell you the spinal marrow 
 would have been in danger of being twisted or com- 
 pressed. A most artificial contrivance is introduced, 
 which prevents this danger — can you describe it? 
 
 A. There are two ligaments, small, but exceed- 
 ingly strong, which are attached to the joint in such a 
 manner, as to allow it sufficient play, but not to admit 
 of any motion beyond a certain extent. They are 
 called the moderator ligaments, from a Latin word 
 signifying to moderate or check. 
 
 S. Then, if I understand it, when we attempt to 
 turn the head upon either side farther than would be 
 safe, one of these cords immediately arrests the mo- 
 tion, like a check rope, such as we sometimes see em- 
 ployed on gates, doors, he, and acting exactly upon 
 the same principle. 
 
 T. But there is another circumstance which it be- 
 longs to our present purpose to understand. You 
 have seen that the structure of the skull is admirably 
 adapted to preserve the brain from being jarred. Is 
 there any harmony of provision for the same purpose, 
 in the structure of the spine, that is, of the support on 
 which the brain immediately rests ? 
 
82 
 
 SPINE. 
 
 A. Between all the twenty-four bones of tjie spine 
 there are springs introduced, of a substance resem- 
 bling gum elastic or Indian rubber. They are carti- 
 lages or gristles ; and may be seen to perfection in a 
 loin of veal. They operate between the vertebrae 
 as so many spring cushions, so that, when we jump 
 or light heavily upon the ground, the violence of the 
 blow is in some measure broken by the spring, and 
 the jar is diminished upon the brain. " We can read- 
 ily understand," says Dr. Bell, "how great the influ- 
 ence of these twenty-four joinings must be in giving 
 elasticity to the whole column ; and how much this 
 tends to the protection of the brain. Were it not 
 for this interposition of elastic material, every motion 
 of the body would produce a jar to the delicate tex- 
 ture of the brain, and we should suffer almost as 
 much in alighting on our feet, as in falling on our 
 head.'' 
 
 But there is another very curious provision for the 
 protection of the brain; the curved form of the spine, 
 which resembles an italic/. Elastic as this bone is, 
 yet if it were perfectly straight, a jar would have ex- 
 tended through it to the head with much more power. 
 Thus, if we should place a ball upon the end of a 
 long, straight spring of steel or whale-bone, and strike 
 the other end upon the ground, the ball would proba- 
 bly be shaken off by the concussion of the blow. But 
 if we first bend the spring in the shape of the letter/, 
 we should see the ball would not be jarred, but would 
 have an easy motion, like a bird rising and falling up- 
 on a bending branch. Thus admirably calculated is 
 
NATURAL THEOLOGY. 
 
 83 
 
 the spine to carry the head without a jar or injury of 
 
 any kind. 
 
 Fig. 11. 
 
 The human spine, so named from a Latin word signifying thorn, 
 on account of the sharp processes, 5, s, s, which project from 
 the bones, and form the outer ridge of the back, a, a, a 
 the cartilages, or plates oS> gristle, inserted between all the 
 vertebrae. It will be seen that in bending backward, the pro- 
 cesses will touch and prevent the motion ; also, that the 
 strongest processes are in the lowest division of the spine, 
 t(there the loins are situated, and where the motions of the 
 back are greatest. In the middle portion, between the verte- 
 brae B, B, it will be observed that the processes are almost 
 in contact with one another ; so that in this part the ^pine 
 hardly admits of any flexure. The ribs enclosing the hearty 
 lungs, &c., are attached to this portion of the spine, and con- 
 sequently, any considerable bending would here be unsafe. 
 In the upper division, the processes are again spread ; tl»i« 
 being required for the flexibility of the neck. 
 
84 SPINE. 
 
 T. Is this wonderful mechanism the same in all 
 
 animals ? 
 
 A. In quadrupeds the number of the vertebrae is 
 from thirty to fifty. In the common serpent it is 
 about three hundred. In the shark the number is 
 somewhat upwards of two hundred. In the eel it ex- 
 ceeds an hundred ; while in common fish it is nearly 
 the same as in quadrupeds. Nor is this all with re- 
 spect to the serpent. Not only is the flexibility of 
 the back increased by the multiplicity of the joints, 
 but the manner in which the vertebrae are united is 
 truly remarkable. They are not united by surfaces 
 which are nearly smooth, as in the spine of a quadru- 
 ped, nor is their flexion impeded in any direction by 
 any projections of the bone. They play freely into 
 one-another like a cup and ball. One extremity is 
 rounded and received into a corresponding cavity in 
 the contiguous vertebra. At the other extremity the 
 arrangement is reversed. Here is a cavity which re- 
 ceives the point of the next bone. So that the whole 
 spine is a continued chain of ball and socket joints, 
 affording a free motion on every side. As a piece of 
 mechanism for pliancy and flexibility, without too 
 much sacrificing a secure union of the joints, it is as 
 palpable a contrivance as a watch-chain, which it 
 does not a little resemble. 
 
 B. This explains why these nimble creatures are 
 able to twist themselves into so many forms. 
 
 T. Yes ; but the more interesting explanation is, 
 it afibrds them a compensation for their want of feet. 
 Having no feet they need this structure of the spine. 
 
NATURAL THEOLOGY. 
 
 85 
 
 J5. I perceive it. As they have to make all their 
 motions with their bodies, if their backs were not as 
 jointed and flexible as possible, they would not be' 
 able to move ; at least, not with any facility. 
 
 T. Do you see any natural cause why the want 
 of feet should have given them an unusual number of 
 bones in their backs ? 
 
 B. 1 see no cause but design. 
 
 A. The vertebrae of the fish differs from that of 
 the serpent in there being a cavity at each end. Ev- 
 ery joint resembles two cups united together by their 
 edges, so as to leave a hollow inclosed space. This 
 space is filled with a gristly substance less solid than 
 bone. One design may be to diminish the weight of 
 the spine, and render the fish thereby more buoyant 
 in the water. 
 
 The neck joints of the bird are remarkable. It is a 
 structure by which the animal is assisted in smoothing 
 and adjusting its feathers, turning its head backward 
 under the wing, and thrusting out or drawing in its 
 beak with rapidity in collecting its food. In the first 
 place, the vertebrae are not united by flat surfaces, as 
 in quadrupeds. They are rounded at the point of 
 contact, so as to roll upon one another with more ease, 
 and be capable of more flexion. Secondly, the upper 
 joints of the neck can only bend forward^ and the un- 
 der ones admit only of a bacJcward motion. The con- 
 sequence is, there are two curvatures in opposite di- 
 rections, like the letter S, so that by spreading or con- 
 tracting them at the same time the neck is lengthened 
 
 H 
 
86 
 
 SPINE. 
 
 or shortened much more expeditiously. The elegant 
 form of the swan's neck is owing to this construction. 
 But there is more to be noticed. The vertebrs of 
 the back are as remarkable for the rigidity of the joints, 
 as inose of the neck for their uncommon flexibility. 
 The bird wants a solid support in the back, to sustain 
 the motions of the wings in flying. Had this portion of 
 the spine been as flexible as in other animals, the body 
 would have been liable to be bent or twisted round. 
 The more unwieldly birds which do not fly, are said 
 to be without this construction. 
 
 B. This is the more remarkable, because it seems 
 to be the very reverse of a natural effect. The natural 
 tendency of the exercise of the wings, I should sup- 
 pose, would be to bend the joints of the back and not 
 to stiffen them. 
 
 A. In general the length of the neck is such, that, 
 added to the head, the length of both is equal to the 
 height of the animals' shoulders from the ground. In 
 some fowls it greatly exceeds this proportion. This 
 is necessary to enable them to seek their food below 
 the surface of the water in which they swim. The 
 same proportion is equally remarkable in quadrupeds ; 
 otherwise they could not easily reach the herbs on 
 which they feed, or the water they drink. Among all 
 those in which this rule is observed, the size of tjie 
 head is less in proportion as the length of the neck is 
 greater. But for this circumstance, the animal would 
 he put to great exertion in raising up his head. This 
 rule, however, is not observed with regard to animals 
 
NATURAL THEOLOGY. 87 
 
 that have means for raising their food without extend- 
 ing their necks, — such, for example, as man, the ele- 
 phant, &c. 
 
 THE BONES. 
 
 T. We might now pass to some other views of 
 this masterpiece of divine wisdom and powder, besides 
 those which invite our attention in the solid parts of 
 the animal structure. But I will detain you a little 
 longer. If the bones and joints have been called the 
 coarsest parts of nature's workmanship, — still they are 
 more easy to be understood, because they more nearly 
 resemble the kind of mechanism to which we are 
 accustomed : we can compare them with works of 
 art ; — and therefore, they are the properest to be al- 
 leged as proofs and specimens of design. There is 
 one remarkable variety in the bones, which challenges 
 our admiration as an evidence of original purpose and 
 wisdom : a portion of them are hollow ; and it is won- 
 derful to observe the skill displayed in the selection ; 
 and the acquaintance exhibited with mechanical prin- 
 ciples. 
 
 A. The bones of the limbs belong to this class. — 
 We may notice the tubular construction in the wing or 
 leg bones of a bird. Mathematicians demonstrate, that 
 in any instrument requiring strength, size, and th« 
 
^^ MECHANISM OF THE BONES. 
 
 greatest possible lightness at the same time, as in the 
 limb bones, for example, the hollow form is the best. 
 Every boy is sensible of the superior strength of a cane 
 pole beyond that of any other rod of the same weight. 
 The reason is, it is hollow. If he should split the cane 
 into strips, and glue the strips together ever so strong- 
 ly, but without leaving any hollow, though he would 
 have the same wood, he would find the rod hardly ca- 
 pable of supporting its own weight. A tin tube has 
 very considerable strength ; but flattened together, 
 that is, no hollow remaining, it bends with ease. We 
 see, therefore, it was not accident, but the skill of a 
 wise Mechanician which has assigned the tubular form 
 to the bones of the limbs, in which strength and light- 
 ness are particularly needed. What is more remark- 
 able, this form is the most conspicuous in the bones 
 of the bird. These animals have the most occasion, 
 plainly, for light bones. Their bones, that is, the 
 hollow bones, differ in three properties. First, the 
 hollows are much larger in proportion to the w^eight of 
 the bone than in those of men or of four footed ani- 
 mals. Secondly, these hollows are empty, or con- 
 tain only air. They have a direct communication also 
 with the lungs ; the air which is received into the 
 lungs, escaping and returning alternately by a hole in 
 some of the bones; whereas, in man, &c., they are 
 filled with marrow. Thirdly, the shell is of a firmer 
 texture than is the substance of other bones ; and 
 therefore, less bone is required to furnish the same de- 
 gree of strength. 
 
NATURAL THEOLOGY. 89 
 
 Why this peculiar advantage bestowed upon the 
 bird ? It could only proceed from a designing intelli- 
 gence. We see nothing in the nature or habits of this 
 animal in particular to funish him with bones more 
 hollow or more empty than those of other species. 
 And again, what natural tendency, which we can im^ 
 agine, has a bone of unusual lightness to cover itself 
 with feathers ? One is suited to the other ; but what 
 effect had one to produce the other? Remarkably 
 hollow bones might naturally enough have occasioned 
 a remarkably nimble animal ; but how could it have 
 given him wings ? We see a connexion of design, and 
 that is all we perceive. 
 
 T. There are nerves and blood-vessels, which en- 
 ter through the sides of the bones. Just for the pur- 
 pose of shewing the wonderful attention which is paid 
 to the most minute particulars where utility is con- 
 cerned, can you mention what anatomists observe as 
 to the direction in which the channels are bored for 
 this purpose ? 
 
 T. The holes are generally winding : they take a 
 zig-zag course, so that they are nowhere in a single 
 line directly across, which would most have weakened 
 the bone. 
 
 B. We often find trees perforated by worms in 
 this serpentine manner ; and Providence has, perhaps, 
 so directed the instinct of these little creatures for the 
 same object. 
 
 A. In all the two hundred and sixty bones in the 
 human body there is not one, but what is suited to its 
 h2 
 
90 MECHANISM OF THE BONES. 
 
 place, or that would do, in any other place. Change 
 the situation, proportion, dimensions, shape, of any 
 bone, — and we can see at once, we violate some me- 
 chanical principle. Yet the bones are original, fixed 
 parts. They do not take their form from our mo- 
 tions. They do not wear into the right configuration. 
 The limbs of the infant are as perfect as those of the 
 adult. They exhibit examples of almost every kind 
 of mechanical power of which their nature' admits,; 
 and whatever be the instance, anatomists observe, it is 
 invariably the simplest, the most beautiful, and the 
 least subject to derangement, which would have an- 
 swered the purpose. 
 
 The manner in which the bones are articulated, or 
 jointed, afibrds evidences of contrivance and contriv- 
 ing wisdom still more striking if possible, than those 
 we discover in the configuration and proportions of the 
 bones themselves. There is nothing perhaps in the 
 whole frame a mechanic would be more likely to no- 
 tice. The greatest curiosity and wonder to him would 
 probably be the appearance of selection, that is to say, 
 the employment of chosen joints in the different limbs, 
 and the admirable adaptation of each to the particular 
 motion required, as well as to the particular dangers 
 of injury in the situation in which it is used. Every 
 child knows that the bones are jointed ; but he is not 
 probably aware that no two joints are exactly alike, 
 except in corresponding parts of the frame. We have 
 the ball and socket joint, the pin or pivot joint, the 
 hinge joint, and as perfect in every respect as could 
 be produced from a cabinet maker's shop. One or 
 
NATURAL THEOLOGY. 91 
 
 Other prevails as may be best adapted to the motion 
 which is wanted. Thus, a hinge joint admits only of 
 a backward and forward motion. We have this joint 
 in our fingers, enabling us to open and close them — 
 which is all the motion that would be of any use. It 
 would have been of no conceivable advantage to have 
 turned the joints of the fingers completely round, so 
 as to bring the nails upon the inside. At the should- 
 er, on the contrary, we want a joint which will per- 
 mit us to stretch and expand the arm in every direc- 
 tion : there we have a hall and socket joint ; where 
 the round head of the bone is received into a cup, 
 which gives it a free play on every side. At the 
 neck, a joint is necessary that will suffer the head 
 to revolve, but the spinal marrow requires that the 
 joint should be subject to no slip, and that no loose 
 motion should be allowed it, which, in the common 
 ball and socket joint, it is difficult to avoid. Here 
 we have a pivot joint, — a joint with a firm pin run- 
 ning up and accurately fitted into a cavity which al- 
 lows the motion demanded, but permits no irregular- 
 ity. Sometimes the same bone is constructed at the 
 opposite ends for different species of joints where dif- 
 ferent kinds of motions happen to be necessary.— 
 Thus, the extremity of the thigh bone is made for a 
 ball and socket joint, where it is united at the hip, but 
 for a hinge joint, where it is united at the knee. The 
 utihty is obvious. A hinge joint at the upper end 
 would have permitted a backward and forward mo- 
 tion, but no other; and not a step could have been 
 taken beyond a certain width, except by spreading 
 
92 MECHANISM OF THE BONES. 
 
 the limbs at the knee to a most awkward and uncom- 
 fortable angle. Again, had the ball and socket been 
 placed at the knee, it would have been less firm than 
 the hinge joint ; — " and there would have been no 
 use that we know of, in being able to turn the calves 
 of our legs before." 
 
 The bones are all cased over at the joints with firm, 
 leathern-like caps, resembling the rings which artists 
 employ to prevent the joints of their machinery from 
 wearing away. The substance is gristle, and it is 
 found in no other part of the bones, but at the joints. 
 Besides this, there is around every joint a little bag 
 which passes from bone to bone, containing a liquid, 
 anatomists call it the synovia, which keeps the surface 
 smooth, and is exactly the same, in effect, with the 
 oil which mechanics employ for a similar purpose. 
 The joints, in short, are both leathered and oiled. 
 
 This fluid is vulgarly called joint-oil, but it has no 
 property of oil. It is more like mucilage, smooth and 
 slippery to the touch ; and therefore better adapted, 
 than any oil to lubricate the interior of the joints and 
 prevent ill effects from friction. It is regularly sup- 
 plied by means of a membrane in the joint furnished 
 with little glands, which pour it out as it is wanted. 
 *' A late improvement,' observes Dr. Paley, * in what 
 are called friction wheels, which consists of a mechan- 
 ism so ordered, as to be regularly dropping oil into a 
 box, which encloses the axis, the nave, and certain 
 balls upon which the nave revolves, may be said, in 
 some sort, to represent the contrivance in the animal 
 joint ; with this superiority, however, on the part of 
 
NATURAL THEOLOGY. 93 
 
 the joints, viz. that here, the oil is not only dropped 
 but made.^^ 
 
 T. This is not the only superiority of the natural 
 contrivance. The more the joints are used, the more 
 abundantly is the oil supplied. It would be thought a 
 wonderful -invention, if a wheel should be so made as 
 ■^o supply more oil to the axis, in case the traveller 
 should see fit to accelerate his speed, or to take up a 
 companion. But this is done in our joints ; that is, 
 ilie lubricating fluid is poured out in increased quan- 
 tities when the joint is in use, and in proportion to 
 its use. 
 
 B. What an exquisite provision ! This will ac- 
 count for the uneasy sensation we experience in mov- 
 ing our limbs, after neglecting exercise for a consider- 
 able time. The oil is deficient. 
 
 T. A trifling item in the catalogue of evils w® 
 bring upon ourselves by indolent habits. Let me ask 
 you what mode of fastening a joint you should sup- 
 pose would be the most safe ? 
 
 B. I know of none so firm as what mechanics al- 
 ways employ, — a bolt. 
 
 T. So, it is probable, a mechanic would say ; but 
 an anatomist would tell him that this would not have 
 answered in the animal structure, and is never em- 
 ployed, A strong band of gristle about the heads of 
 the bones is the fastening made use of; and it forms 
 almost the only instance in which nature has departed 
 from our mechanical expedients. 
 
 B. The advantage, I now perceive, is very plain, 
 though it did not occur to me. Had the joints beea 
 
94 MECHANISM OF THE BONES. 
 
 secured by a solid pivot, or any thing^ absolutely in- 
 flexible, the limbs would be more endangered. In 
 extreme accidents the gristle will yield, and permit 
 the limb to slip, without breaking the bone. All the 
 remedy required is a smart extension of the cords ; 
 whereas, if a bolt would have been more secure, the 
 difficulty is, it would have been too secure ; since it is 
 often the case that, if the joint did not give way, the 
 bone must. 
 
 A. " In considering the joints,' observes Dr Pa- 
 ley, * there is nothing which ought to move our grati- 
 tude more than the reflection, how well they t^jear. A 
 limb shall swing upon its hinge, or play in its socket, 
 many hundred times in an hour for sixty years to- 
 gether, without diminution of its agility ; which is a 
 long time for any thing to last ; for any thing so much 
 worked and exercised as the joints are." 
 
 T. Are there any remarkable varieties in the joints 
 of different animals ? 
 
 A. There are fishes which have joints of which the 
 skeleton of man and animals generally furnish no exam- 
 ples. They are to be seen in the fin. The general 
 structure of the fin resembles a fan, being composed 
 of spines, or long slender bones, with a membrane be- 
 tween them, which when raised from the body and 
 spread out, answers the purpose of a paddle, and 
 sometimes of a weapon of attack or defence. When 
 employed for the latter purpose it evidently requires 
 as much firmness as possible. In ihe pectoral fin of 
 some fishes there is a curious provision by which this 
 object is effected. A mechanic might be challenged 
 
NATURAL THEOLOGY. 95 
 
 to invent a more simple and beautiful contrivance. 
 The first spine of the fin, the first stick of the fan, has 
 a moveable bone in the shape of a. ring attached to 
 the lower extremity, which plays, upon another bone 
 that is immoveable. The ring bone has a hook, and 
 it is in the power of the animal, by turning the bone 
 round, to fasten the hook into a particular hole in the 
 immoveable bone. In this manner the fin becomes 
 so securely fixed that it cannot be moved except by a 
 motion directly contrary to that which hooked it to 
 the other. Any attempt to brush down the fin with- 
 out regularly unlocking it is ineftec.tual. It is thus 
 the siluri and the gasterostei give firmness to their fins 
 when they wish to employ them as weapons of de- 
 fence or assault. 
 
 T. You may describe some of the principal bones, 
 besides those which have been mentioned. 
 THE ARM. 
 
 A. The arm is a remarkable piece of mechanism. 
 
 The situation of the arm upon the body is best ac- 
 commodated to the uses of the limb, as every one 
 will realize by imagining a different position. 
 
 By being jointed it is capable of a much greater 
 variety of motions, than though it had been a single 
 bone. Without a hinge in the middle, it would have 
 been unmanageable ; with a multitude of joints it 
 would have wanted strength. It consists of three 
 bones ; one above the elbow, called the humerus ; the 
 other two between the elbow and the wrist. Of the 
 last, the one which is in a line with the thumb is 
 termed the radius — the other, the ulna. 
 
96 MECHANISM OF THE BONES. 
 
 T. What is the wisdom of this mechanism ? Why 
 one bone for the upper, and two for the lower arm ? — 
 Why is there not the same number of bones in both 
 parts of the arm ? 
 
 A. it would be difficult to imagine a more striking 
 instance of mechanical ingenuity than we have in the 
 double bone of the lower arm. One of the bones, 
 (the ulna), makesa hinge at the elbow, and permits 
 the arm to bend. The other has no concern in the 
 hinge : it barely touches at the elbow, and may be 
 said to be loose. But this arrangement is exactly the 
 opposite at the wrist. Here the bone which is hinged 
 at the elbow is only permitted to touch ; and that, on 
 the contrary, which touches at the elbow is united to 
 the hand by a hinge. When we want to bend the 
 arm, we use one hinge ; and when to perform the 
 same motion at the wrist, we employ the other. Had 
 these two motions been performed upon one and the 
 same bone, with a hinge at each extremity, the hand 
 could have swung backward and forward, — ^but it 
 could not have revolved ; we could not have turned 
 the palm of the hand upward or downward. For 
 there can be no turning round, it is evident, upon a 
 hinge joint. If the hand must turn, the bone must 
 turn also to which it is hinged on ; and must therefore 
 be loose at the elbow, aud the elbow hinge must be 
 assigned to another bone. Such is the contrivance 
 actually adopted ! 
 
 B. Any one might think how happy it is that we 
 are furnished with a double bone in a part we use so 
 much, so as to keep it more firm and steady under the 
 
NATURAL THEOLOGY. ,97 
 
 great pressures for which we have occasion at the 
 wrist and elbow; but few are probably aware how 
 ingenious it is, and how necessary to enable us to per- 
 form one of the most simple motions of the hand. 
 Here is an example of creative skill which is always 
 before us. Truly may we say, that to be convinced 
 of the hand of God, we have only to look upon our 
 own. 
 
 T. But you have not finished the description of 
 this remarkable workmanship. 
 
 A. The construction adopted gives the benefit of 
 a long shaft to the hand running as high as the elbow. 
 This supports the joint when we turn the hand with 
 a strong twist, much more than if the hand had been 
 set to the wrist by a simple socket. If we grasp the 
 arm a little above the wrist, when we roll the hand 
 we shall feel the shaft bone revolving. A mechanic 
 would understand the ingenuity of this structure ;-as 
 an improved instrument, for screwing and wrenching, 
 has recently been invented in almost exact imitation 
 of' the human wrist. It is obvious that the muscles 
 which roll the hand are applied to much greater ef- 
 fect by means of this contrivance ; for we find up- 
 on examination, a part is attached along upon the 
 upper extremity of the shaft, — just as in using a pair 
 of pincers, we always apply our strength at the ends 
 of the handles. 
 
 It may here be mentioned, that the monkey has 
 one more bone in the wrist than is found in the hu- 
 man species. 
 
 I 
 
98 
 
 MECHANISM OF THE BONES. 
 
 THE UPPER ARM. 
 
 The upper arm displays a different kind of mechan- 
 ism. It makes a hinge at the elbow, permitting the 
 
 Fig. 12. 
 
 Fis. 13. 
 
 Figure 12. 
 tf, the humerus, or bone of the upper arm, exhibiting the ball or 
 rounded head at the top, which is received into a socket at 
 the shoulder, forming an universal joint. JR, the radium, or 
 bone which turns with the hand, and is hinged at the wrist. 
 M, the ulna, which is hinged at the elbow, and by which we 
 perform all the motions of bending or extending the arm. 
 
 Figure 13. 
 A small portion of the humerus, and also of the radius and ulna, 
 exhibiting the structure of the elbow joint. R, being the ra- 
 dius which is loose from the joint, for the purpose of enabling 
 the hand, which is hinged at the opposite extremity, to re- 
 volve. 
 
 arm to bend : but at the shoulder we have what is 
 called a ball and socket joint ; that is, a universal 
 joint, which will turn in every direction. If we 
 
NATURAL THEOLOGY. 99 
 
 double one hand into the shape of a ball, and turn 
 it round in the other, this would resemble the joint at 
 the upper extremity of the arm. Now, the hinge 
 joint, we can see, does well at the elbow ; but at the 
 shoulder, it would have deprived us of half the use 
 of our arms. It must have kept them always at the 
 same distance from the body ; they would have 
 swung forever in one particular line, like the arms of 
 a loom. 
 
 The provision for uniting the arm to the body is in 
 some material respects a very remarkable structure. 
 It can only be appreciated, as it deserves, by one 
 who will be at the pains to reflect upon all the pos- 
 sible modes in which the object could be effected — in 
 which the arm could be attached by a firm and sub- 
 stantial joint. The ribs are evidently too slender and 
 weak to sustain a great pressure at a single point no 
 larger than the head of the arm bone. The arm, 
 therefore, could not be jointed to a rih. It would 
 have been forced into the body by the first violent ef- 
 fort. The spine w^ould have been still more endan- 
 gered. But no other bone remains in that neighbor- 
 hood, belonging to the united frame of the trunk ; the 
 collar bone and breast bone excepted, which are evi- 
 dently out of the question. We have here an obvi- 
 ous difficulty, and it is wonderful to see how it has 
 been surmounted. A broad, flat bone, called the sea- 
 pula or shoulder-blade, is spread outside a number of 
 ribs together, against which the arm rests, and 
 to which it is attached — and whereby the pressure is 
 so much extended as to occasion no danger to the 
 
100 MECHANISM OF THE BONES. 
 
 frail materials underneath. A mechanic would say, 
 there is a elect put in between the shore and the build- 
 ing to save the building from injury. It is loosely 
 bedded in the flesh ; and is itself capable of motion. 
 This perfects the provision. As the shore inclines 
 to either side, the cleet shifts likewise, so as to keep 
 the bearing, as nearly as possible, always equally true. 
 
 Fig, 14. 
 
 », the scapula, or shoulder blade. 
 
 B. What a perfect piece of artificial contrivance ! 
 Truly, there is no end to the skill exhibited in the 
 formation of the human frame. We have constant 
 occasion to exclaim, how fearfully and w^onderfully 
 are we made ! 
 
 T. And nothing more disposes us to this devout 
 admiration than perceiving some new occasion for it, 
 which is one of the great advantages of the subject we 
 are now pursuing. 
 
 THE RIBS. 
 
 The rib bones are a far more curious and surprising 
 structure than most persons are aware. 
 
NATURAL THEOLOGY. ' 101 
 
 A. Besides protecting the heart and the lungs, 
 and this use alone, in respect to the heai^t especially, 
 would have been sufficient evidence of design, they 
 are made to render another service which a hasty ob- 
 server would hardly have suspected. The play of 
 the lungs is referrible to the arrangement, of these 
 bones. As breathing is nothing more than the rising 
 and falling of the lungs, which operate like a pair of 
 bellows, a contrivance was wanted to perform this 
 mechanical operation. We mark in the provision 
 adopted, the admirable simplicity, — as a mechanic 
 would say, the happy thought, of the expedient. 
 The contrivance is this. The rib bones are united 
 to the spine in a direction sloping downwards. Being 
 firmly attached at the ends where they are set on, the 
 consequence of their sloping is, that when they come 
 to rise, the muscles which pull them up necessarily 
 draw them out, upon the principle of an umbrella. 
 The cavity of the chest is consequently enlarged, 
 and the lungs are permitted to fill, as the air rushes 
 into the bellows when they are extended. Again, by 
 sinking down into their former position, the cavity is 
 diminished and the breath is forced out. 
 
 B. One cannot but reflect with admiration upon 
 how slight a piece of mechanism' our lives are depend- 
 ing ; that is to say, upon the right choice of so sim- 
 ple a circumstance,, as whether the ribs in their nat- 
 ural position, should pass directly around the chest, 
 as most persons, it is likely, have never observed but 
 that they do ; or should have a slight degree of 
 inclination downwards. 
 
 I 2 
 
102 MECHANISM OF THE BONES. 
 
 .Fig, 15. 
 
 The spine, ribs and hreast hone, or sternum, which constitute the 
 frame work of the chest or thorax. Referring, however, to 
 the plate, or to nature, we observe, that the ribs are not con- 
 tinued throughout from the spine to the sternum, but they 
 are eked out and joined to the breast bone by means of pieces 
 of gristle of a form corresponding to that of the ribs, — being 
 as it were a completion of the arch of the rib by a substance 
 more adapted to yield in every shock or motion of the body. 
 A severe blow upon the ribs does not break them, because 
 their extremities are tipped with this elastic or springy sub- 
 Btance, which recoils and yields to the violence. It will also 
 be noticed how much the same construction must assist the 
 play of the chest in the operation of breathing. The muscles 
 of respiration enlarge the capacity of the chest by elevating 
 tlie ribs ; and during the momentary interval of muscular ac- 
 tion, the gristly parts of the ribs, from their great elasticity, 
 restore them to their former position. 
 
NATURAL THEOLOGY. 103 
 
 T. This is stating the case a little too strongly, 
 though I am sensible of an admirable author you 
 may have so understood. It was not, I presume, his 
 intention to suggest, there could have been no en- 
 largement and contraction of the chest, if the ribs, 
 in their natural position, had passed directly around 
 the body. But then this is certain, the motion in 
 this case, must have been very considerable in the 
 ribs to have produced any effect ; whereas a slight 
 rising from a sloping position changes the cavity of 
 the chest immediately. 
 
 B. This is very plain. We can see it exempli- 
 fied by placing our hands against our sides with the 
 fingers touching in front, so as to resemble ribs. If 
 they pass directly across, a slight motion does not 
 change their distance from the breast ; and if they 
 were the real ribs, this motion would not effect any 
 change in the capacity of the chest : but, if we first 
 slope them downwards, we find a trivial rising ex- 
 tends them instantly from the body. 
 
 T. There is other mechanism beside the ribs con- 
 cerned in the action of breathing or respiration ; espe- 
 cially the rising and falling of the diaphragm, which 
 is a muscle that separates the chest from the cavity 
 beneath. And the wisdom of this is the more observa- 
 ble, as the ribs are liable to lose their elasticity by 
 age, and sometimes become incapable of motion. 
 
 THE LOWER LIMBS. 
 
 The LIMBS, which carry and support the body, 
 form another remarkable part of our structure. 
 
104 MECHANISM OF THE BONES. 
 
 A. Each of them is composed, that is, the up- 
 right limbs, of three bones, the same number as in 
 the arm : the two lower, called the tihia, a.ndjibula, 
 between the knee and the ankle, supporting a single 
 bone w^hich joins immediately to the body, and is 
 called the femur or thigh bone. But notwithstand- 
 ing this general resemblance between the two sets of 
 limbs, there are some remarkable differences, which 
 are adapted still further to increase our devout admi- 
 ration of the wisdom and intelligence exhibited in 
 the animal frame. 
 
 Below the knee the limb swings backwards ; be- 
 low the elbow, it is the reverse. We can assign no 
 natural reason why limbs, which otherwise are so 
 similar, should have been hung so differently. But 
 we see the advantage, — for let a person only reflect 
 on the uncomfortable effects of an opposite arrange- 
 menU 
 
 The upper single bone in the lower limbs is much 
 stronger than the upper single bone corresponding to 
 it in the arm. Indeed, the thigh bone is the strong- 
 est bone in the frame. We observe the design. 
 This bone has to sustain the weight of the body, and 
 the additional weight of every burden we carry. 
 
 It is united to the hip by a ball and socket joint, 
 as is the upper bone of the arm at the shoulder blade. 
 But the socket at the shoulder is shallow ; while that 
 of the hip is the deepest in the whole body. "This," 
 says Dr. Paley, " agrees well with the duties assign- 
 ed to each part. The arm is an instrument of mo- 
 tion principally, if not solely, and accordingly re- 
 
NATURAL THEOLOGY. 105 
 
 quires a shoaler socket to allow it a freer play. — 
 Whereas the thigh bone forming a part of the column 
 of the body, having to support the body, firmness 
 was principally to be consulted." Upon natural 
 principles, however, the deeper socket ought to 
 have been at the shoulder. At the hip the pressure 
 of the bone is never against the bottom of the re- 
 ceptacle, so as to tend naturally, as one might say, 
 to deepen the cavity. At the shoulder, on the con- 
 trary, the head of the arm always forces into the cup 
 in which it moves. The neck of the thigh bone is 
 bent over, and enters sideways. Consequently, there 
 
 16. 
 
 This figure exhibits the neck of the femur or thigh bone, bent 
 over, and inserted by the head into the socket at a. 
 
 is no pressing inward at this joint. We see why the 
 hip socket should be made deep to prevent the bone 
 
106 MECHANISM OF THE BONES. 
 
 from thrusting by, as it is not directly under the sup- 
 port : that is. we see the wisdom of God, but we dis- 
 cover no other cause. Every natural tendency that 
 we can conceive of, would have been precisely the 
 reverse. The same remark will apply to instances 
 without number in the animal frame, where a happy 
 construction is apparently the opposite of a natural 
 effect, and can only be referred to a designing Intelli- 
 gence. 
 
 B. This is certainly very skilful and striking ; but 
 I would ask why the necesity of the oblique position 
 of the thigh bone ? 
 
 T. If you will endeavor in walking to place it in 
 a straight position, by keeping the feet so far apart that 
 the limbs shall be perfectly parallel to one another and 
 perpendicular to the ground, you will find it produces 
 a rolling effect when you rise from one foot to the oth- 
 er, as if mounted upon stilts. This is relieved by the 
 dishing or oblique direction of the bones — and you 
 will perceive it could be avoided in no other mode. 
 Dr. Bell, in the Library of Useful Knowledge, has 
 some curious remarks upon the form and position of 
 the thigh bone, showing how it is calculated for 
 strength in consequence of the obliquity, and in which 
 he compares it to the dishing of a wheel. 
 
 But there is another provision in this remarkable 
 structure which invites our attention, — the manner 
 in which the hip joint is secured. 
 
 A. The joints in general, are united by means of 
 a strong band of gristle encompassing the heads of the 
 bones. This is the case in the ball and socket joint at 
 
NATURAL THEOLOGY. lOt 
 
 the shoulder. If a mechanic wanted to fasten a ball in- 
 to a cup, so as to allow free play to the ball, he would 
 adopt the same measure. Now, it is wonderful to 
 observe, that in addition to this security, the hip, a far 
 more important joint than the shoulder, and more 
 dangerous to be dislocated, and from the position of 
 the neck of the bone, more liable to dislocation, ex- 
 hibits an additional security, — and a more mechanical, 
 artificial contrivance one might be challenged to im- 
 agine. It is this : a short, strong, yet pliable ligament 
 resembling a leathern thong, is inserted by one end 
 into the head of the bone, and by the other into the 
 bottom of the socket. — It is hardly practicable to break 
 it. It will scarcely admit of being even extended. 
 Its situation is such that it cannot be cut, without clea- 
 ving the bone. Whoever will reflect upon this single 
 provision, taking into view its singular importance to 
 this joint, and that it is not generally assigned to the 
 other joints, and then how precisely it is what our 
 own expedient would have been in a similar case, — 
 must be disposed to say with Paley, "Jif is an in- 
 stance upon which I lay my hand. For the purpose 
 of addressing different understandings and different 
 apprehensions, for the purpose of sentiment, for the 
 purpose of exciting admiration of the Creator's works, 
 we diversify our views, we multiply examples : but, 
 for the purpose of strict argument, one clear instance 
 is sufficient ; and not only sufficient, but capable, 
 perhaps, of generating a firmer assurance, than what 
 can arise from a divided attention." 
 
108 
 
 MECHANISM OF THE BONES. 
 
 Fig. 17. 
 
 A part of the hip joint is here taken off, for the purpose of ex- 
 hibiting the round ligament a, which is seen connecting the 
 head of the thigh bone with the bottom of the socket. It al- 
 lows considerable latitude of motion, at the same time it is 
 the great safeguard against dislocation. It is hardly imagino- 
 ble how great a force is necessary to stretch, still more to 
 break this ligament ; — yet so flexible is it as to oppose no im- 
 pediment to the suppleness of the joint. 
 
 T. We will now close the description of the bones 
 and joints, with another striking instance of wisdom 
 and design in the formation of the foot. 
 
 THE FOOT. 
 
 A. The FOOT is composed of twenty-six little 
 bones, united together by gristle, a very elastic sub- 
 stance under a hard pressure. So many joints impart 
 the advantage of a spring — and of enabling the foot 
 to conform itself to the surfaces of objects upon which 
 we tread. Any one must be sensible of the incon- 
 
NATURAL THEOLOGY. 109 
 
 venience of a wooden foot*^; and the inconvenience 
 would be, it would have no spring ; and would be in- 
 capable of suiting its shape to the inequalities upon 
 which we stand or walk. But the number of bones 
 is only a part of this admirable mechanism. The 
 arching of the foot is an obvious proof of contrivance. 
 If the bottom of the foot was perfectly flat, it is plain 
 it must have had a heavy and uncomfortable effect. 
 One may easily perceive this, by lashing the bottom 
 of the foot to a strip of wood. There could be no 
 spring with a flat foot. But as the construction is, 
 the two extremities only of the foot rest upon the 
 ground, while the elastic arch in the centre yields to 
 the pressure, and causes the weight of the body when 
 we walk, to play, as it were, upon a constant spring. 
 
 B. We now see the use of the heel, and it is 
 a use which one would not immediately think of It 
 helps to form the arch. 
 
 T. But this is not all the use. 
 
 A. The heel is not directly under the leg, but ex- 
 tends back like a spur, and is united to the main body 
 of the foot, by a very firm, but still a considerably 
 springy joint. The effect of this is, when the heej 
 touches the ground in walking, and it touches first, — 
 in consequence of its being formed like a spur, and 
 having a spring at the same time, the whole weight of 
 
 the body does not come down with a sudden jolt ; 
 
 there is not only a yielding in the point of support, 
 but we descend in a curve, the centre of which is the 
 ball of the heel. If it were not for this contrivance- 
 
 K 
 
110 MECHANISM OF THE BONES. 
 
 we should always walk as upon stilts. The leg would 
 strike the ground, like a cane. 
 
 Fig. 18. 
 
 In this figure the foot is represented as descending to the ground 
 in a semicircle from the point of the heel. Owing to this 
 circumstance, in connexion with the elasticity of the parts, 
 the force of the blow is diminished. 
 
 T. Are there any peculiarities in the feet or 
 limbs of different animals, adapted to their particu- 
 lar necessities ? 
 
 A. In the first place the foot of the monkey, as 
 well as the hand exhibits a structure unlike that of the 
 human species. The monkey's foot has an additional 
 muscle. The muscles which move the toes are also 
 differently disposed, and compel the animal to rest 
 more upon the outer edge of the foot than upon the 
 bottom. In the limbs of all animals, though not so 
 much in the heavier species, there are sloping joints, 
 or joints which make a bend. This enables the limbs 
 to give or spring in some degree, under the weight 
 of the body, so as to prevent a pounding stroke. In 
 the horse, for example, we perceive the whole length 
 of the limb from the body to the ground, is very far 
 
NATURAL THEOLOGY. Ill 
 
 from being a straight line. Besides the bends about 
 midway of the hind legs, which are the limbs with 
 which the animal has most occasion to spring — there 
 is one upon every leg just above the hoof, called the 
 fetlock joint. And then there is a spring even in the 
 hoof. " The flatness of the hoof, which stretches 
 out on each side, and the frog coming down in the 
 middle between the quarters, adds greatly to the 
 springiness of the foot. Ignorant smiths, by shaping 
 and fixing the shoe improperly, often deprive the 
 animal of the benefit of this provision. His foot 
 strikes the ground with an unyielding blow, and 
 inflammation and lameness at last ensue." 
 
 B. They are not always acquainted, it is likely, 
 with this curious structure ; but it is a pity so much 
 sufiering should be occasioned for the want of a little 
 attention. 
 
 A. This admirable mechanism of the foot, which 
 Providence has so kindly adapted to the wants of dif- 
 ferent animals, is strikingly exemplified in the case of 
 the reindeer. "It inhabits a country covered with 
 snow the greater part of the year, and its hoof is 
 admirably formed for going over that cold and light 
 substance without sinking into it or being frozen. 
 The under side is covered entirely with hair, of a 
 warm and close texture. And the hoof altogether is 
 very broad, acting exactly like the snow shoes which 
 men have constructed for giving them a large space tr 
 stand on their feet and thus to avoid sinking. More- 
 over, the deer spreads the hoof as wide as possible, 
 when it touches the ground, but as this breadth would 
 
112 MECHANISM OF THE BONES. 
 
 be inconvenient in the 'air, by occasioning a greater 
 resistance from the air, while he is moving along, no 
 sooner does he lift the hoof, than the two parts into 
 which it is cloven fall together, and so lessen the sur- 
 face exposed to the air." 
 
 T. But there is another structure of the foot 
 which will lead us still farther to admire the wisdom 
 and contrivance exhibited in the animal mechanism. 
 
 A. It is that of the fly, by which it is enabled to 
 walk upon a perpendicular wall. 
 
 B. This motion in these little insects always 
 seems unaccountable, especially when they run so 
 fast upon a glass window. The only reason I can 
 tliink of is, that they have something sticky upon 
 their feet, — or that there are rough places in the 
 glass or wall by which they are able to climb up, 
 
 T. Any thing adhesive upon the foot would be 
 a constant impediment, especially to an insect, — and 
 to have to climb up upon points would be excessively 
 inconvenient. They are enabled to perform this mo- 
 tion by a most curious philosophical contrivance^ 
 Can you describe it? It forms one of the innumerable 
 instances in which we discover the powers of science, 
 if we may so express it, subservient to the opera- 
 tions of an all wise and Creative Intelligence. 
 
 A. The air is said to exert a pressure upon bodies 
 equal to between fourteen or fifteen pounds to every 
 square inch of surface, so that upon one of our hand.- 
 the weight of the atmosphere is more than two hun- 
 dred and fifty pounds. The hand is not borne down- 
 ward; because the air presses alike in every direction. 
 
NATURAL THEOLOGY. 
 
 113 
 
 and therefore the downward pressure is resisted by an 
 upward one precisely equal. But if the air on one side 
 of the hand was removed, the weight upon the other 
 side would remain unbalanced, and we should be sen- 
 sible of the force exerted. An experiment is easily 
 tried. If we put a piece of burning paper into a wine 
 glass and then suddenly cover it with the hand, thfe 
 hand will be holden fast to the glass. The reason is, 
 the air has been in some measure expelled by the fire, 
 so that there is now an unequal pressure upon the two 
 surfaces of the hand, the greater pressure being above, 
 which produces the effect we experience. If we could 
 press our foot upon the floor with sufficient force to 
 make the sole absolutely touch at every point, and per- 
 fectly expel every particle of the atmosphere, there 
 would be the same effect. A foot of the common 
 size would be holden down with a w^eight more than 
 equal to that of a barrel of flour ; it could no more be 
 lifted than if such a weight were placed upon it, not 
 till in some manner the sole was drawn up, beginning 
 at one edge and gradually letting in the air, like rais- 
 ing a plaster. This is found to be the construction of 
 the fly's foot. There is a skin or flap upon the sole 
 which it can draw down so close upon the wall as to 
 squeeze out the air completely, and the consequence is 
 that the foot adheres with considerable force. 
 
 It has also been found that some of the large am- 
 phibious animals which inhabit the polar regions have 
 the same formation of the foot, only upon a greater 
 scale. By this means they are able to climb the 
 floating masses of ice among which they live. 
 k2 
 
114 MECHANISM OF THE MUSCLES. 
 
 B. So we have here the principle of an air pump. 
 How impossible to imagine any thing hut intelUgence, 
 when we witness such examples of philosophical 
 mechanism ! 
 
 In the feet of aquatic birds, besides the web or 
 membrane between the toes by which they are ena- 
 bled to make a broader and more powerful stroke up- 
 on the water, another peculiarity has been less fre- 
 quently noticed, viz. that their feet are situated fur- 
 ther back than those of other birds. This enables 
 them to thrust themselves forward more directly and 
 with greater force in the water. The breast is not 
 tipped down, when the animal strikes the water be- 
 hind, because the breasts of all aquatichhds are pecu- 
 liarly broad and covered with oily feathers which ren- 
 der them so buoyant, that this position of the feet is 
 even necessary to enable the animal to dive, by means 
 of the stroke of the feet so near the hinder extremity 
 of the body. Their legs also are shorter in propor- 
 tion than usual, in consequence of which the resis- 
 tance of the water is diminished. 
 
 MUSCLES AND TENDONS. 
 
 A, We now come to another view of this won- 
 derful workmanship. Having surveyed the admirable 
 mechanism of the frame work, we are next to see the 
 curious machinery which the All-wise Artificer has 
 employed for putting all this apparatus in motion. 
 
 By what meaiis are the motions of the bones 
 performed ? 
 
 A. By what are called the muscles and tendons. 
 Though the flesh has the appearance, at first view, of 
 
NATURAL THEOLOGY. 115 
 
 tone general mass of substance spread over the bones, 
 it is, in fact, composed of five hundred and twenty- 
 seven separate strips of different sizes and shapes ; 
 and each of these is what is termed a muscle. They 
 play freely over one another, and have a fatty matter 
 between, which renders their motions easy. If the 
 whole flesh of the body was dissected, as it would naU 
 urally separate, it would come apart in these five hun- 
 dred and twenty seven strips, as smooth and as clean 
 as so many straps of gum elastic. Each of them 
 may be termed a rope to produce some particular mo- 
 tion. The middle is fleshy and red, and usually 
 takes the name of the muscle. This portion is al- 
 ways the largest ; then it goes on diminishing in size 
 towards each extremity, where it terminates in a white 
 leathery string or strap, which is called the tendon. 
 Every muscle, with a few exceptions, is fastened 
 between two different bones, going from one to the 
 other ; and the object is, to pull the bones together, or 
 to draw them in any direction which the pulling would 
 give them. Thus are all the motions of the bones 
 performed. If we tie a strap of gum elastic to our 
 tliumb and finger, and spread them open so as to ex- 
 tend the strap ,.jlie force it will exert to draw them 
 together, may give us a very tolerable idea of the 
 action of a muscle upon the bones to which it is at- 
 tached. 
 
 T. As the muscle, however, is not found to be 
 any thing like gum elastic, what makes it contract so 
 as to pull upon the bones ? 
 
 A. The middle or fleshy part has the power of 
 shortening itself at our will ; and in some instances 
 
116 MECHANISM OF THE MUSCLES. 
 
 the muscle seems to act of its own accord ; this is 
 about all the explanation our knowledge of the subject 
 at present enables us to give ; except that there are 
 little shining threads, called the nerves, and which 
 are fine branches of the spinal marrow or brain, that 
 enter into all the muscles, ''and which, if divided or 
 injured, the muscle is deprived of all its power. 
 When the muscle shortens, it swells. If we bend the 
 arm, and grasp it at the same time, a little above the 
 elbow, we feel a swelling under the hand ; — the mus- 
 cle, which contracts, and produces the flexure, being 
 situated in that part of the arm. 
 
 T. As you have a clear idea, I perceive, of 
 a muscle, we will look at some of the examples of 
 Creative skill and design in this part of our structure. 
 If an artist were to contrive a machine with wires 
 and strings to produce an imitation of our motions, 
 how would he apply his apparatus to effect opposite 
 movements with the same part ? — to make the arm, 
 for example, move backward and forward ? 
 
 A. Wherever a string was employed to pull for^ 
 ward any part, there would be a corresponding one 
 on the opposite side to draw it hack ; and all the 
 strings would be divided into pairs for this purpose. 
 It is exactly the same in the living structure. The 
 muscles are in pairs. To move the arm fonvard 
 there is a muscle before ; to move it backw^ard there 
 is a muscle behind. It were difficult to conceive 
 what could be more expressive of design. 
 
 B. In the five hundred and twenty-seven muscles, 
 therefore, w^e have as many separate arguments of 
 design, as there are pairs, into which the muscles 
 
natuAal theology. II7 
 
 can be divided. If it could be imagined that a single 
 example was possibly accidental ; that there happens 
 by chance, to be a muscle to straighten the arm — and 
 another to bend it, how are we to believe this of two 
 hundred and fifty examples ; or that all the muscles 
 happen accidentally to be paired ? 
 
 T. What is, if possible, a more wonderful evi- 
 dence of design, it is said, the flexor muscles, (so na- 
 med from a Latin word, signifying to bend,) have 
 fibres of greater strength and more numerous than 
 those of the extensors, or the muscles which merely 
 extend and recover the limb ; — and that the flexors 
 which have to make the principal effort, are fastened 
 to better advantage, for the exertion of their power. 
 B. What manifest purpose and intelligence ! 
 When we bend the arm, it is generally to lift 
 a weight, but never when we straighten it ; and 
 hence we require stronger flexors than extensors; 
 and the superior strength of the former is not owing, 
 it seems, to exercise, but to the original structure of 
 the muscle. There are more strands to the rope, 
 
 T. What part of the contrivance of a muscle is 
 the tendon, or the white, leathery string in which the 
 muscle usually terminates ? 
 
 A. Besides that the tendon is much more firm 
 and tough than the muscle, and therefore more fit for 
 fastening to the bone, for which purpose it is employ- 
 ed ; the muscle or fleshy part can be placed in any 
 situation which is most convenient, and its motion be 
 communicated by means of the tendons, like so 
 many wires and strings to any part where the motion 
 m^J be wanted, Thus, there are many tendons 
 
118 MECHANISM OF THE MUSCLES. 
 
 which pass down to the fingers, while the muscles 
 that pull them are situated out of the way in the arm 
 ahove, without encumbering the wrist, palms, and de- 
 licate little members upon which they draw. It is 
 like having the water wheel of a manufactory in 
 a separate room, and communicating its power by 
 bands and smaller machinery into the apartments 
 where it is wanted. 
 
 T. Is there any particular wisdom discovered in 
 the structure of a tendon ? 
 
 A, It is the perfection of a rope. We see the 
 reason of its superiority upon mechanical principles, 
 that is, in part we see it, from the higher skill which 
 is employed as to the manner of laying the strands or 
 fibres together, to give it the greatest strength. To 
 understand what is necessary to the strength of a rope 
 or cable, we must learn what has been the object of 
 the improvements and patents in this manufacture^. 
 The first process in rope making, is placing the long fi- 
 bres of the hemp side by side, or parallel to one another. 
 The second, is spinning the hemp into yarns. And 
 here the principle must be attended to,, which goes 
 through the whole process in forming a cable ; 
 which is, that the fibres of the hemp shall bear an 
 equal strain. The third, is making the strands. The 
 last step of the process is forming the strands into 
 ropes. The difficulty of the art has been to make 
 them bear alike, especially in great cables, and this 
 has been the object in patent machinery. In the 
 twisting of the yarns, and then of the strands, those 
 which are on the outer surface must be more strecthed 
 
NATURAL THEOLOGY. Il9 
 
 than those near the centre ; consequently, when there 
 is a strain upon the rope, the outer fibres will break 
 first and the others in succession. A rope, of a new 
 patent, has been made, which is said to be many times 
 stronger than any other cord of the same dimensions. 
 The strands are plaited, (that is, interwoven or in- 
 terlaced as in a splice or braid,) instead of being twis- 
 ted. Now, if the strong tendon of the heel, or 
 Achilles' tendon, be taken as an example, it will be 
 found to consist of subdivisions, which are like the 
 strands of a rope ; but instead of being parallel 
 or twisted, they are plaited or interwoven in a man- 
 ner which could not be imitated in cordage by the 
 turning of a wheel. * 
 
 B. It is wonderful how many difierent kinds of 
 arts are exemplified in the animal structure. We 
 have had that of the cabinet maker, and the teles- 
 cope maker, and several others, — and now we have 
 that of the rope maker in perfection. 
 
 T. You have given the celebrated Dr. Bell's 
 account of the tendons, upon which you will find 
 some observations in Arnott on the Elements of 
 Physics. All other cords and bands wear out or are 
 weakened by use. Is this the case with the muscles 
 and tendons ? 
 
 A. It is not, but the reverse. They become fir- 
 mer and stronger by exercise ; and it shows the 
 kind wisdom of Providence, that when any employ- 
 ment happens to call for greater muscular efibrt in 
 
 *Dr. Bell. 
 
120 MECHANISM OF THE MUSCLES. 
 
 any particular part, as that of the porter in the back ; 
 the sailor in the hands and arras, &c. ; the strength 
 necessary is made to arise from the very exertions 
 which requires it. The necessity furnishes its own 
 supply. 
 
 B. This is as though the sailor were to change 
 a small rope into a cal^le, merely by fastening on an 
 anchor. Creative power alone can accomplish such 
 wonders. 
 
 T. The subject is of so much concern to us in 
 many respects, that it is important the principle 
 should be remembered. Do you recollect Dr. Bell's 
 observations in his Animal Mechanics ? 
 
 A. " Exercise," he remarks, " unfolds fully the 
 muscular system, producing a full, bold outline of the 
 limbs, at the same time that the joints are knit, small 
 and clean. In the loins, thighs and legs of a dancer, 
 we see the muscular system fully developed, and 
 when we turn our attention to his puny and dispro- 
 portioned arms, we acknowledge the cause, that in 
 the one instance, exercise has produced perfection, 
 and that in the other, the want of it, has occasioned 
 deformity. Look to the legs of a poor Irishman, 
 travelling to the harvest with bear feet ; the thick- 
 ness and roundness of the calf show that the foot 
 and toes are free to prevent the exercise of the mus- 
 cles of the leg. Look, again, to the leg of an En- 
 glish peasant, whose foot and ankle are tightly laced 
 in a shoe with a wooden sole, and you will perceive 
 from the manner in which he lifts his legs, that the 
 play of the ankle, foot, and toes, is lost as much as if 
 
NATURAL THEOLOGY. ISk 
 
 lie went on stilts, and, therefore, are his legs small 
 and shapeless." 
 
 B. I have read that those who are employed at the 
 different quays in I^ondon, to load and unload ships 
 sometimes carry burthens which would almost, kill 
 a horse ; and that men who are accustomed to hunt- 
 ing will outrun horses, or at least can bear the e:jf- 
 ercise longer ; and even in walking, a man, who has 
 been in the habit of it, will go further in a day than 
 a horse can ; and if he do not accomplish it the first 
 day, he will be able to continue his journey many days 
 without inconvenience, while the horse will be ex- 
 hausted with fatigue in much less time. It is said by 
 travellers that Hottentots can outstrip horses ; and that 
 the savages in America who hunt the elk pursue these 
 animals, though they are as fleet as stags, till they tire 
 them out and catch them. The civilized part of man- 
 kind seem not to be acquainted w^ith their own- 
 strength ; and indeed they are so situated as to have 
 Ihtle occasion for great physical exertions. — But we 
 should praise the admirable wisdom with which the 
 body is formed, to be capable of them when they are 
 rendered necessary. 
 
 T. Though but a small part of the muscular pow- 
 er of which we are capable may be called into use in 
 the ordinary occupations of life," the body that is 
 strengthened by habits of temperance and exercise is 
 best adapted to resist disease, and to withstand the 
 effects of exposure. The vigor of the mind partici- 
 pates with that of the body, and professional writers 
 observe that the very shape is injuriously affected by 
 
. 122 MECHANISM OF THE MUSCLES. 
 
 indolent and effeminate habits. — The muscles by 
 which the joints are compressed and kept in their 
 right position become relaxed ; the consequence of 
 which is, that the bones are gradually displaced, and 
 produce deformity. The curvature of the spine and 
 shoulders is supposed to be often owing to this cause; 
 and hence exercise and active employments are now 
 principally recommended to correct any such tenden- 
 cy, especially in those young persons who are in pe- 
 culiar danger of so serious an evil, from the greater 
 delicacy of their system, and more sedentary and re- 
 tired habits. We very rarely observe any such im- 
 perfection among the laboring classes. 
 
 Anatomists notice a remarkable attention to me- 
 chanical principles, in the situation of the muscles, — 
 and the manner in which they are applied to move 
 the limbs. 
 
 A. First, there are always muscles where the 
 bone would admit of any motion, but no where be- 
 sides ; that is, in all the five hundred and twenty-sev- 
 en muscles, there is not one mislaid, or rendered 
 useless by its situation ; there is not one which pulls 
 against the joint without effect ; and further, there is 
 not a single motion of which the form of the bone and 
 joint will admit, but there is a muscle or set of mus- 
 cles provided to produce that motion. This admir- 
 able harmony is one of the most striking evidences 
 of an Intelligent Architeect. It is the same as in 
 examining the rigging of a ship, to find through all 
 the intricacy of the tackle, every rope suited to its 
 place. 
 
NATURAL THEOLOGT. 123 
 
 The manner in which the muscles apply their 
 power to move the bones discovers a perfect acquain- 
 tance with the mechanical laws pertinent to such ca- 
 ses. Generally speaking, every muscle is fastened 
 firmly at one end to a bone it cannot move, or which 
 is sufficiently fast to pull by, and, at the other, to the 
 bone it is intended to move or to pull upon. A cord 
 tied between a door and the partition may give a very 
 good idea of the action of a muscle. The moving 
 bone is the door ; the joint, is the hinge ; while the 
 shortening of the muscle moves the bone, in the same 
 manner, as the shortening of the string moves the 
 door. Thus a muscle is fastened to the bone of the 
 upper arm which comes down over the elbow joint, 
 and is attached to the arm below. By the contrac- 
 tion of this muscle the lower arm is raised up. - • 
 
 Fig. 19. 
 
 In this figure b represents the bone of the upper arm ; a, the 
 muscle which bends the fore arm, and which is inserted below 
 the elbow into the radius at d. It will be seen that the short- 
 ening of this muscle must necessarily raise the arm, d, c. 
 
 T. And what is observable is, that the place 
 where the muscle is fastened to the moving bone, is 
 
124 MECHANISM OF THE MUSCLES. 
 
 SO very near the joint. Here is an admirable atten- 
 tion to mechanical laws. 
 
 B. This does not seem very intelligible. One 
 would think the muscle would pull to great disadvan- 
 tage from being inserted so close to the joint. It 
 would seem like drawing to a door with a string fast- 
 ened just by the hinge, v/hich every one knows would 
 make it very hard to move the door. The elbow 
 certainly appears to be bent with a great loss of me- 
 chanical power. Itv/ouldseem far better if the mus- 
 cle, which raises the fore arm had reached down to 
 the hand, and been inserted at c. This would have 
 given a greater purchase. 
 
 A. The advantage obtained is this, and the door 
 is a good explanation. When the string is fastened 
 very near the hinge, it requires a strong pull to draw 
 the door ;blit then, if the strength is sufficient, it will 
 make the door move much more swiftly than if the 
 string V7ere attached at a greater distance from the 
 hinge. So, when a mechanic is raising a ladder, if 
 he is able to lift it up by taking hold of one of the 
 lower rounds, close to the foot, where the ladder 
 turns upon the ground, — we may say, where the 
 hinge is, in that case he will do the business much 
 more quickly than if he were to begin at the farther 
 end. Thus, the nearer the joint the muscle acts, the 
 swifter the motion produced, provided the strength 
 of the muscles is sufficient, 
 
 T. And for this, provision is made. The Creator 
 has given sufficient vital power to the muscles to ad- 
 mit of this sacrifice of the mechanical ov lever power„ 
 
NATURAL THEOLOGY, 125 
 
 as they evidently require to be stronger on account of 
 their insertion so near the joint. Thus, a small 
 thread would move a door, if applied to the handle, 
 though it would snap asunder, if fastened close to the 
 hinge. But let it be a strong cord and a powerful 
 hand, and the nearer the hinge the better for a swift 
 motion. Now, rapid motions are necessary to us in 
 a thousand familiar actions. 
 
 B. I perceive it. The rajpidity of the motion 
 is frequently the first object required ; as in cleaving 
 wood, driving a nail, he. Here a slow motion, how- 
 ever forcible would not answer the purpose. A gi- 
 ant could not ^ress a wedge into a stick of timber. 
 By the present arrangement, I see we have an ap- 
 plication of the muscular power without which it 
 would be insufficient for many actions quite necessary 
 for our existence, and the all-wise Artist has rather 
 chosen to strengthen the power itself, and subject it 
 to some mechanical disadvantages, than not to assign 
 it the best situation for the uses for which it is re- 
 quired. How amazing is that skill which has so 
 wisely arranged every part of our frame ! 
 
 T. We seem to understand this organization so 
 well, I will venture upon another still more curious. 
 
 B. When we visit a manufactory we are eager to 
 get some general idea of the machinery : how much 
 more interested should we feel to obtain what insight 
 we can into the works of our Almighty and benefi- 
 cent Creator! 
 
 Ti I was going to state a curious fact respecting 
 the muscles, and I beg your attention. Between 
 L2 
 
126 MECHANISM OF THE MUSCLES. 
 
 every two ribs on each side of the body there are 
 muscles to pull these ribs together, which is one 
 part of the operation of breathing. It is necessary, 
 you perceive, the motion should be capable of being 
 performed very quickly, because we sometimes have 
 occasion to breathe very quickly. How is this mO' 
 tion best effected ? 
 
 B. One would say, by having the muscles, that 
 pull the ribs together^ pass as straight across, as 
 possible. 
 
 T. So it might seem * but it is just the reverse, 
 in principle an^ fact. The muscles do not go direct- 
 ly across from bone to bone ; that is, the strands or 
 fibres of the muscles slo^e very much from one 
 bone to the other. Can you explain it ? If so, you 
 will know something of a curious principle in me- 
 chanics and of the wisdom with which you are made 
 at the same time. 
 
 A. The door seems to illustrate it very plainly. 
 If the door of a room be thrown back against the 
 partition, and a person, pulling it with a string, stand 
 close to the door post,-*— in this situation, the line 
 will slope along in the same direction very nearly 
 with the door. Shortening the cord a foot or two 
 now, he will perceive this sloping position of the 
 line, produces a much quicker motion in the door 
 than pulling in the same quantity, when the door 
 has come to, so that the line is no longer flat with 
 the door, but nearly perpendicular to it. Whoever 
 tries the experiment will find it to be so. Now, the 
 
NATURAL THEOLOGY. 127 
 
 shying direction of the muscular fibres between the 
 ribs must operate in the same way. It must produce 
 a swifter motion than in any other position in which 
 the muscles could be applied. 
 
 a, d, c, b, two ribs exhibiting a part of the intervening muscles, 
 passing obliquely from bone to bone ; by which direction of 
 the muscles a mechanical advantage is obtained as to the 
 quickness of the motion, for the purpose of respiration or 
 breathing. 
 
 But there is a still more remarkable circumstance 
 to be noticed in the structure before us, which shows 
 the perfect foresight, and knowledge of mechanical 
 laws exhibited in our frame. Do you not perceive that 
 the sidelong action of these muscular strings a, h, 
 must tend, while they pull the ribs together, to give 
 II sidelong motion to the bones themselves, to cause 
 the rib «, dy to move to the right and the rib c, h, to 
 the left, and thus make them crowd against the 
 places where their ends are inserted ? 
 
 A. It shows creative wisdom in our structure, 
 that this difficulty seems evidently to have been con- 
 templated. There are two sets of muscles employ- 
 
128 MECHANISM OF THE MUSCLES. 
 
 ed lying one upon another, which not only increase 
 the muscular power, but which by sloping different 
 ways, balance each other's sidelong tendency. 
 
 T. This single construction appears to me one 
 of the most striking evidences of design in the an- 
 imal frame. 
 
 B. When the tendons, have occasion to make 
 a sudden bend, as those do which come down and 
 turn at the instep to raise the foot, what is to 
 prevent them from rising up whenever they shorten 
 and pull ? One would suppose the sinews would 
 spring off from the top of the foot, — ^which would 
 certainly be very awkward and unpleasant. 
 
 T. What if you should be told there are cross 
 straps of ligament by which they are all confined 
 down ; exactly as a mechanic would do in a similar 
 case ? The straps are just under the skin and are 
 very slippery and smooth so as so bind the sinews in 
 their places, but allow them a free motion. The 
 tendons at the wrist are bound down in this manner 
 by a band resembling a lady's bracelet, as exhibited 
 in this figure. 
 
NATURAL THEOLOGT. 
 
 129 
 
 Fig, 21. 
 
 a, the annular ligament of the wrist, under which pass the ten- 
 dons of the muscles of the fingers. 
 
 B. What manifest design ! One finds that to raise 
 difficuhies, is only preparing the way for some new- 
 demonstration of wisdom in this wonderful work of 
 the Creator. 
 
 T. Can you mention any examples in the muscles, 
 of that species of mechanical contrivance which is 
 called the pulley 1 
 
 A. Sometimes the situation of parts is such that 
 a motion is wanted, where for some reasons it is not 
 
130 MECHANISM OF THE MUSCLES. 
 
 SO well to place a muscle, or bring it to act in the 
 usual way. For example. A muscle is necessary 
 to draw down the lower jaw, and this is done by 
 a muscle inserted above the jaw. Nothing is more 
 common in mechanics, than pulling one way to make 
 the object move in the very opposite. But then the 
 rope must pass through a ring or pulley. The sai- 
 lor pulls down, and the cask comes up. He has 
 a pulley above through which his rope is roven. The 
 same contrivance is adopted in the present instance ; 
 the muscle called the digastric muscle, descends from 
 the side of the head, and passes through a loop in 
 the neck below the jaw whence it ascends and is at- 
 tached to the part to be drawn. 
 
 Fig. 22. 
 
 a, the digastric muscle, which is represented as coming down and 
 passing through a slit or ring in another muscle indicated by 
 the line b. After leaving the ring where it is formed into a 
 round, strong tendon, it again becomes fleshy, runs upward, 
 and is inserted into the chin to draw the jaw down, c, ig a 
 bone called the os-hyoideSf which seems to operate as a stay 
 or brace ; the muscle containing the loop is fastened at d. 
 
"" NATURAL THEOLOGY. 131 
 
 B, I know not what contrivance could be more 
 plain, nor how any one can look upon it, without be- 
 ing persuaded of a desiging intelligence. 
 
 T. We have another example of the same kind 
 in the trochlear muscle of the eye, from a Latin 
 word signifying a pulley. 
 
 A» This muscle arises from the bottom of the 
 orbit or socket, and then comes forward and passes 
 through a loop on the inner edge of the socket, in 
 advance of the level of the eye, whence it returns 
 and is fastened to the ball : of course, when the 
 muscle contracts it rolls the eye. It operates ex- 
 actly in the same manner as a rope in a ship is car- 
 ried over a block or round a stay, in order to make it 
 pull in the direction which is wanted ; or, as in raising 
 one end of a stone pillar, the rope is passed forward 
 of the object, and then is reverted through a ring or 
 pulley as at a, in the following figure, and attached 
 to the weight to be drawn up. 
 
 Fig. 23. 
 
132 JIECHANISM OF THE MUSCLES. 
 
 Fig. 24. 
 
 e, the trochlear muscle, which arises at the bottom of the socket 
 of the eye, and passes upward and forward like the rope in 
 the figure 23, till it readies the pulley at d, on the inner 
 edge of the bony rim arcnd the front of the eye, where it is , 
 turned backwards, and inserted into the top of the ball. 
 
 T. There is quite as curious an example in the 
 wing of the bird. 
 
 A. It is necessary the weight of the bird should 
 hang below the wings, so as to balance the body- 
 in the air, and prevent it from turning over ; — for the 
 weight of the body under the wings is the same as 
 the ballast of a vessel under the sails. This requires 
 that the muscles which constitute the principal part 
 of the weight, should be disposed as much as possi- 
 ble upon the breast, and this principle we find to be 
 observed. Every one who has seen a fowl upon the 
 table, knows that upon the back, above the wing, 
 there is only a mere skin. But the question arises, 
 if the muscles, which are wanted to raise the wings, 
 ere situated beneath them, how are the wings to be 
 elevated in the act of flying ? As the muscle can 
 only contract downwards, how is this to produce a 
 
NATURAL THEOLOGY. 133 
 
 rising motion ? The contrivance which a mechanic 
 would have employed is that which is actually adopt- 
 ed. The tendon of the muscle passes up from the 
 breast, above the wings, and is there inflected 
 through a ring or^pulley, and fastened to the top of 
 the wing bone, and is thus enabled to perform the 
 service required. 
 
 Fig, 25. 
 
 d, and c, the two pectoral or Irmst muscles dissected and raised 
 from the breast bone a : d, being the larger muscle for draw- 
 ing down the wing ; and c, the elevating muscle. The .ten- 
 don of c, is represented above the wing joint at/, elevated by 
 a pin and inserted into the wing bone, a short distance from 
 the joint. 
 
 B. How curious to notice the exact resemblance 
 in the manner in which the gaff of a vessel is drawn 
 up on which the sail is spread, and that which is here 
 employed in raising and expanding the wing 1 
 
 M 
 
134 MECHANISM OF THE MUSCLES. 
 
 Fig. 26. 
 
 c, the gaff or rod upon which the sail is suspended, elevated by 
 a rope b, passing through a pulley at a, above the sail, exactly 
 as in the bird's wing, and for the same reason, viz. the ne- 
 cessity of applying the power below the part which is to be. 
 raised. 
 
 T. You have mentioned several examples which 
 illustrate applications of the mechanical powers in 
 the animal structure, which are among the most con- 
 fessed proofs of skill and contrivance in our own 
 mechanism. Besides many more that might be 
 addedj there is one which Dr. Paley calls, "that 
 most exquisite of all contrivances, the nictitating 
 membrane," (from a Latin word, signifying to wink,) 
 which is found in the eyes of birds and of many 
 quadrupeds. 
 
 A. The white skin which we sometimes see 
 fowls and birds suddenly twitching over their eye 
 balls, is this membrane, " and the use is to sweep th« 
 
NATURAL THEOLOGY. 
 
 135 
 
 eye, which it does in an instant ; to spread over it 
 the lachrymal humor ; to defend it also from sudden 
 injuries ; yet not totally, when drawn over the pupil, 
 to shut out the light. The commodiousness with 
 which it lies folded up in one corner of the eye, 
 ready for use and action, and the quickness with 
 which it executes its purpose, are properties known 
 and obvious to every observer." But what is equally 
 admirable, is the manner in which it performs its 
 office. It is an elastic substance, like Indian rubber, 
 and when drawn out, returns of its own accord, thus 
 saving the necessity of a muscle for this purpose. 
 
 We are next to notice what the French Academi- 
 cians call the marvellous mechanism, by which this 
 membrane is drawn over the eye. There is a string 
 or tendon attached to the edge of the curtain, and 
 which is connected with a muscle in the back part of 
 the eye. When the muscle exerts itself, the mem- 
 brane, by means of the communicating thread, is 
 instantly drawn over the eye ball. But what is so 
 deservedly called marvellous in this construction, is 
 this. ^^ The muscle which pulls jthe membrane, is 
 /passed through a loop farmed by another muscle ; 
 and is there inflecte-d, as if it were ^ound a pulley. 
 This is a peculiarity, and observe the advantage of 
 it. A single muscle with a straight tendon, which is 
 the common muscular form, would have been suffi- 
 cient, if it had the power to draw far enough. But 
 the contraction necessary to draw the membrane over 
 the whole eye, required a longer muscle thain could 
 lie straight at the bottom of the eye. Therefore, in 
 
136 MECHANISM OF THE MUSCLES. 
 
 order to have a greater length in a less compass, the 
 cord of the main muscle makes an angle. This, so 
 far, answered the end ; but, still further, it makes an 
 angle, not round a fixed pivot, but round a loop form- 
 ed by another muscle ; which second muscle, when- 
 ever it contracts, of course twitches the first muscle 
 at the point of inflection, and thereby assists the ac- 
 tion designed by both ;" the main muscle and the 
 loop muscle act at the same time, and thus conspire 
 in the operation of drawing over the curtain. 
 
 B. One can hardly realize that this is a descrip- 
 tion of a natural structure. We acknowledge a Cre- 
 ator indeed, and must expect to discover the proofs 
 of a Creator in our examination of his works ; but 
 yet the devoutest reception of the truth hardly seems 
 to prepare us for observing without surprise, such 
 actual demonstrations of skill as we perceive testify- 
 ing to the existence, agency, and wisdom of the De- 
 ity in every object around us. 
 
 T. Does the motion of the muscles and tendons 
 always depend upon our will ? 
 
 A. It is happy they do not in every instance. 
 The muscles immediately connected with life, or 
 which move the vital organs, are independent of our 
 will. They act, as far as we can perceive, of their 
 own accord. We move the hand by our own choice, 
 and its motion is never wanted, but when we are able 
 to will it. But, as Paley says, " we should have enough 
 to do, if we had to keep our hearts beating, our lungs 
 in motion, and our stomachs at work. Did these 
 things depend upon our attention they would leave us 
 
NATURAL THEOLOGY. 137 
 
 leisure for nothing else. We must have been continually 
 \ipon the watch and continually in fear, nor would this 
 constitution have allowed of sleep." He might have 
 added, we should hardly have performed these func- 
 tions with the exactness and regularity they demand, 
 had they been left to our vigilance and care. 
 
 B. This explains why birds are able to sleep, and 
 yet poise themselves so exactly upon the pei'ch and 
 keep from falling. There is, I suppose, an involun- 
 tary action of the muscles by which they grasp the 
 branch. 
 
 T. This may be partly the explanation, but it is 
 not the whole. There is more mechanical contri- 
 vance for the benefit of the bird. In trussing a fowl, 
 upon bending the legs toward the body, the cook 
 finds the claws close of their own accord. Now this 
 is the very position in which the bird rests, while it 
 loosts upon its perch ; and in this position it roosts in 
 safety. By simply crooking its limbs it produces 
 a contraction of the claws, which remain fast without 
 any voluntary effort as it continues to sit. It is ow- 
 ing to this, — the muscle whiafi pulls the claws to- 
 gether and which comes down the leg for that purpose, 
 is carried round the joints in such a manner in its 
 way to the toes, that it is long enough to reach per- 
 fectly the whole distance only when the animal stands 
 upright, — and, therefore, in a^ sitting posture, the 
 claws are necessarily contracted. In this way the 
 bird is enabled to roost in safety, even when agitated 
 by the winds. 
 
 m2' 
 
138 MECHANISM OF THE MUSCLES. 
 
 Fig. 27. 
 
 a, the muscle going over the joint at b, and passing behind the leg, 
 and around the joint at c, and then coming down behind the 
 foot at d, it proceeds to the claws ; and the weight of the bird 
 bending the joints h and c, the muscle is bent at the same 
 time, and the claws are drawn closely and firmly around the 
 perch. 
 
 B. It has often appeared to me wonderful that 
 birds should be able to rest so quietly upon a rocking 
 branch, without losinf their hold and falling off in 
 their sleep. I see there is nothing overlooked by 
 the wisdom of the Creator, and that not even a spar- 
 row alights without him. 
 
 A. "In some animals which are sometimes obli- 
 ged to stand for a great length of time, we find curi- 
 ous contrivances for assisting the action of the mus- 
 cles. Thus, the sea birds, as the heron, which wade 
 upon the shores of the sea and in the marches for 
 
NATURAL THEOLOGF. 139 
 
 fish and reptiles, their natural food, had long excite<i 
 the curiosity of naturalists, by the length of time in 
 which they would stand motionless, expecting their 
 prey. At last it was found, that in the lower ex- 
 tremity of the thigh bone there is a deep cavity into 
 which a corresponding projection in the leg can be 
 shut at the pleasure of the anihial. . The thigh and 
 leg being thus firmly locked together, and to all 
 intents and purposes, constituting but one piece, 
 no muscular power is necessary to keep them ex- 
 tended." 
 
 ALIMENTARY ORGANS. 
 
 T. You have attended to some of the principal 
 manifestations of creative wisdom exhibited in the 
 Senses ; in the frame work of the animal structure, 
 the bones ; and the muscles by which they are put in 
 motion : We shall now notice the no less striking 
 displays of design and wisdom which appear in the 
 means provided to sustain the body, and preserve it in 
 life and vigor. The alimentary apparatus, or that for 
 nourishing the system, brings into view a new class 
 of phenomena. We shall first describe the mouth. 
 
140 ALIMENTARY ORGANS. 
 
 THE MOUTH. 
 
 A. *'In comparing the different animals," says 
 Dr. Paley, " I know no part of their structure which 
 exhibits greater variety, or in that variety a nicer ac- 
 commodation to their respective convenience, than that 
 which is seen in the different formation of their mouths. 
 Whether the purpose be the reception of ahment mere- 
 ly, or the catching of prey, the picking'up of seeds, the 
 cropping of herbage, the extraction of juices, the suc- 
 tion of liquids, the breaking and grinding of food the 
 taste of that food, together with the respiration of air, 
 and in conjunction with the utterance of sound ; these 
 various offices are assigned to this one part, and in 
 different species, provided for, as they are wanted by 
 its different constitution. In the human species, for- 
 asmuch as there are hands to convey the food to the 
 mouth, the mouth is flat, and by reason of its flatness 
 fitted only for reception. Whereas the projecting 
 jaws, &;c. of the dog and his affinities, enable them 
 to apply their mouths to snatch and seize the object 
 of their pursuit. 
 
 The full hps, the rough tongue, the corrugated cartil- 
 aginous palate, the points and ridges in the roof of the 
 mouth, directed backwards, which assist grazing ani- 
 mals in swallowing their food, the broad cutting teeth 
 of t^e ox, the deer, the horse and the sheep, qualify 
 this tribe for browsing uipon their pasture. The retiring 
 under jav/ of the swine vjorJcs in the grounds, after 
 the protruding snout, like a prong or ploughshare, 
 
NATURAL THEOLOGr. 141 
 
 has made its way to the roots upon which it feeds. 
 A conformation, so happy, was not the gift of chance. 
 
 In birds this organ assumes a new character ; new, 
 both in substance and in form, but in both, wonder- 
 fully adapted to the wants and uses of a distinct 
 mode of existence. The sharp edge and tempered 
 point of the sparrow^ s bill, picks almost every kind of 
 seed from its concealment in the plant ; and not only 
 so, but hulls the grain, breaks and shatters the coats 
 of the seed, in order to get at the kernel. The hook- 
 ed hesk of the hawk tribe, separates the flesh from 
 the bones of the animals which it feeds upon, almost 
 with the clearness and precision of a dissector's 
 knife. 
 
 Every thing about the animal mouth is mechanical. 
 The teeth of lobsters, work one against another, like 
 .lie sides of a pair of shears. In many insects, the 
 mouth is converted into a pump or sucker, fitted at 
 the end, sometimes with pincers ; by which double 
 provision, viz. of the tube and the penetrating form 
 of the point, the insect first bores the necessary open- 
 ing and then extracts the juices. And, what is most 
 extraordinary of all, one sort of mouth, as the occa- 
 sion requires, shall be changed into another. The 
 caterpillar could not live without teeth ; in several 
 species, the butterfly formed from it, could not use 
 them. The old teeth therefore, are cast off", and a 
 new and totally different apparatus assumes their place 
 in the fly. Thus, through the whole animal kingdom, 
 the form of the mouth or the appendages attached to 
 it, are kindly adaptedto the necessities of the creature, 
 
142 ALIMENTARY ORGANS. 
 
 It is said that quadrupeds, apes not excepted, have 
 fewer muscles in the lips than are met with in the hu- 
 man species ; of course, they have less variety in the 
 motions of the mouth, which is probably one reason 
 they are not capable of imitating the human voice, or 
 of uttering articulate sounds ; and adds another item 
 to the innumerable proofs that nature has placed an 
 original barrier between ourselves and every being 
 she has placed around us in the animal world. 
 
 T. Among all the parts and powers which belong 
 to this curious structure, none are perhaps more re- 
 markable, or more plainly evince contrivance and de- 
 sign, than the instruments provided for breaking and 
 bruising the aliment, viz. the teeth. 
 
 THE TEETH. 
 
 A. They form the same proofs of purpose and 
 intention, as a knife for cutting, or a mill for grinding. 
 No other bone in the body has any tendency to shoot 
 out little pegs, except the very two, where it 
 would be difficult to dispense with th&m. We per- 
 ceive design, and that is all ; for it is no explanation 
 to say there is a pulp within the sockets, which forms 
 and makes these teeth. The pulp is a part of the 
 provision, and the question still recurs, how came 
 it in the jaws alone ? As the teeth do not admit, like 
 our other bones, of being covered with flesh to pre- 
 serve them from the air, to which no bone in the 
 body would bear to be exposed, they are plaited 
 over with a glassy substance, called enamel, which 
 gives them also another advantage, that of superior 
 
NATURAL THEOLOGY. 143 
 
 hardness. Tliey consists of a proper mixture of 
 cutters and grinders suited to our food, and the due 
 preparation of it for the stomach. The jaws are so 
 constri^cted, and the teeth so situated in them, that 
 when either cutters or grinders are engaged, and both 
 are not usually wanted at once, the others are not 
 permitted to touch, or to wear upon one another. 
 Again, the teeth do not commonly make their ap- 
 pearance in the mouth during the period of infancy, 
 when they would be worse than useless. Lastly, as 
 the teeth are needed before the jaws have attained 
 their full size, there is provision for a second, or sup- 
 pletory set when the bones of the jaws have grown 
 so large, that it would be impossible the first should 
 sit compact and occupy the whole extent of the 
 gums. 
 
 Another thing observable in the teeth is, they are 
 shed in succession, so as not to leave an interval in 
 which we are without a sufficient number. — The 
 elephant sheds his teeth, but not, it is said, in our 
 manner. An account given of this matter is very 
 curious, that having never more than eight grinders, 
 often no more than four, an upper and under on each 
 side, the shedding of one of w^hich would of course 
 leave a side of his mouth very much disabled for 
 masticating his food, his second teeth, or rather the 
 succeeding parts of the same tooth, always come up 
 behind the first, and the one continues to serve till 
 the others are ready to take their places. 
 
 The wisdom of Providence appears in adapting 
 the teeth of different animals to the nature of their 
 stomachs. It is one of the most striking instances of 
 
144 
 
 ALIMENTARY ORGANS. 
 
 that wonderful design we discover in the animal 
 system. If the nature of the stomach be such as is 
 the case in cats, tigers, lions, he. that it will only- 
 digest animal food — the teeth are particularly fitted 
 for tearing and separating flesh. On the contrary, if 
 the nature of the digestive organs be such as to re- 
 quire vegetable food, as in the horse, ox, and many 
 others, the teeth are flat, rough and of large surface 
 resembling a millstone, and fitted only for grinding. 
 The grinder of a horse or an ox, is a mechanical curi- 
 osity. There are ridges of the hardest enamel which 
 rise up above the surface and run down to a consid- 
 erable depth. These ridges are filled in between with 
 a somewhat softer substance resembhng marble ; the 
 consequence of which is, that the spaces v)ear away 
 easier than the ridges, and thus the tooth is kept 
 always rough and fit for the operation of breaking and 
 grinding the vegetable substances upon which the an- 
 imal lives. 
 
 Fig. 28. 
 
 A GriiideT, or one of the Molares of a horse, (from a Latin word 
 signifying a mill stone) ; a. the enamel forming a raised 
 edge around the tooth : the white lines in the middle repre- 
 senting the plates of enamel in the interior of the tooth, 
 h. the earthy part interposed, which, by wearing away more 
 easily, leaves the ridges of enamel projecting above. 
 
NATUBAL THEOLOGY. 145 
 
 B. How perfectly is the object accomplished by 
 this admirable contrivance [ A millwright would be 
 puzzled to say how two surfaces could be made to 
 grind continually upon one another without requiring 
 to be picJced ; always wearing away — and yet for 
 years preserving nearly the same projecting elevation 
 upon the surface. We here see the solution of this 
 mechanical problem. 
 
 A. Another remarkable structure appears in the 
 other teethj viz. the cutting teeth, for the bene- 
 fit of certain animals. It is seen in the gnawing 
 animals, such as the squirrel, mouse, ratj &:c. As 
 these animals have occasion for sharp front teeth, 
 there is, first, a curious provision for this purpose. 
 The enamel is only upon the forward part of their 
 gnawing teeth. The back part is of a softer kind of 
 bone. The effect is, that the back naturally wears 
 down and leaves the enamel in the form of a sharp 
 edge. The front teeth of these animals resemble a 
 bevelled tool, or a chisel, and it is owing to this happy 
 construction. But they must necessarily wear away 
 very fast, and wonderful as it may seem, it is said 
 they run back nearly the whole length of the jaw, 
 under the roots of the other teeth, in sockets pro- 
 vided for that purpose, from which they shoot up, as 
 the edges wear down. It is exactly the same con- 
 trivance as the pencil cases in which the pencil is 
 made to screw out, as the pencil is cut away. 
 
 B. What inexhaustible varieties of creative kind- 
 ness and skill 1 I suppose, if it were not the nature 
 
 N 
 
146 ALIMENTARY ORGANS. 
 
 of these animals to gnaw upon hard substances, this 
 singular growth of their teeth would prove an un- 
 comfortable provision. 
 
 T. There is but little danger, with their existing 
 habits and propensities, of their neglecting this pre- 
 caution ; but it is said, that, if fed only upon soft 
 substances, their teeth will grow so as to penetrate 
 the head and destroy the life of the animal. Before 
 dismissing the subject, there is another consummate 
 evidence of design, viz. the wonderful relation be- 
 tween the different parts of the mouth. 
 
 A. The form of the teeth and the motions of the 
 jaws in all animals always correspond. The mouths 
 of the cat, wolf, dog and those animals which have 
 teeth and digestive organs suited only for flesh which 
 requires to be divided by an upward and downward 
 motion, have the jaw constructed in such a manner as 
 not to admit of any lateral or side way action, such as 
 we notice in sheep, oxen, and the like, and which 
 would have been useless to flesh eating animals. This 
 could not be chance. — For what but design could 
 have effected such harmony of construction between 
 parts so entirely different as the stomach, the teeth, 
 and the joints by which the mouth is opened and 
 closed. The animal structure is full, — is made up of 
 such relations. So completely is it carried through ev- 
 ery part ; every part is so fitted to connected parts ; 
 and that without the least natural tendency that we 
 can see, — for what particular tendency can a jaw with- 
 out grinding teeth have to unite itself to the head by 
 a joint incapable of grinding, — this correspondency 
 
NATURAL THEOLOGY. 147 
 
 is SO perfect, that from one single bone, or fragment 
 of a bone, the naturalist tells us the shape, motions, 
 arid habits of the animal. 
 
 T. The -next remarkable example under this 
 head is the structure of the throat. 
 
 THE THROAT. 
 
 A. The throat is the channel for conveying the 
 food from the mouth to another set of apparatus, 
 where the process of converting it into nourishment is 
 to be completed. It might seem a simple provision 
 to furnish a tube ' from the mouth to the stomach. 
 But there are difficulties which afford new occasion 
 to admire the consummate skill which has contrived 
 every part of our frame. In the first place, we must 
 be able to swallow with ease. 
 
 B. I do not see any occasion for much contri- 
 vance to enable the food to di'ojt down the throat. 
 One would naturally suppose that it would fall of its 
 own accord. 
 
 A. I dare say you have heard of some exceptions, 
 however, and the failure of one instance, might pro- 
 duce the most serious consequences. Many articles 
 of food, are of a light and spongy nature, and if taken 
 in great quantities, would not be liable to effect their 
 descent by their own weight. But the still stronger 
 case is that of the animals whose swallowing is not 
 a descending, but an ascending operation. The con- 
 trivance is the most mechanical possible. There are 
 muscular fibres or strings in the lining of the throat, 
 
148 ALIMENTARY ORGANS. 
 
 which run round the passage, and which, by drawing 
 the throat together above the food, as the food pro- 
 ceeds, force it along in its descent. In the horse, ox, 
 &,c. which have to swallow in a direction contrary 
 to the weight of the food, there is a double set of 
 these forcing muscles, which cross one another around 
 the throat, and act with a much greater power. 
 
 B. I have often wondered that these animals 
 should be able to raise their drink and food with 
 such perfect ease into their long necks. The most 
 familiar circumstances, I perceive, furnish occasion 
 to admit the skill and kindness of that Creator, who 
 giveth to the beast his food, and whose tender mer- 
 cies are over all his works. 
 
 T. But this is only a small part of the contrivance 
 necessary in furnishing us with a throat. 
 
 A. The lungs open into the throat. The open- 
 ing is called the glottis, and is situated in the upper 
 part of the throat, just below the palate. It is ne- 
 cessary for breathing ; but still — a dangerous opening 
 we perceive, from a place where a crumb of bread 
 might be fatal, into the great channel through which 
 all our food has to descend. But the foresight was 
 equal to the peril. It is wonderful to notice how the 
 danger has been avoided. The opening is covered 
 with a small valve, or clapper, opening upwards, an- 
 atomist call it the epiglottis, which plays over the 
 entrance, and which the food closes before it in its 
 descent. Nor is this the whole of this beautiful 
 contrivance. The glottis itself is so constructed, 
 that it draws together, whenever any particle of liqui d 
 
NATURAL THEOLOGY. 149 
 
 or solid substance attempts to enter it. Besides both 
 these provisions, the passage into the lungs is made 
 so sensitive to the least touch of any liquid or solid 
 substance, even a drop of water, as to produce 
 a convulsion or cough instantaneously, when a parti- 
 cle of food or drink attempts to go the wrong way, 
 as it is called, — and forces it back with violence. 
 The membrane which lines the passage from the 
 glottis into the lungs, anatomists term it the tra- 
 chea, "is perhaps the most sensible and irritable mem- 
 brane of the whole body. It rejects the touch of a 
 crumb of bread, br a drop of water, with a spasm which 
 convulses the whole frame ; yet, left to itself and its 
 proper office, the reception of air alone, nothing can 
 be so quiet. It does not even make itself felt ; a man 
 does not know that he has a trachea. The capacity 
 of perceiving with such acuteness — this impatience 
 of offence, yet perfect rest and ease, when let alone — 
 are properties one would have thought not likely to 
 reside in the same subject. It is to the junction, 
 however, of these almost inconsistent qualities, in 
 this as well as in some other delicate parts of the 
 body, that we owe our safety and our comfort; our 
 safety to their sensibility, our comfort, to their re- 
 pose." What artist would venture upon so exquisite 
 a piece of mechanism, as that of a valve which 
 should be always opening, under a current of water, 
 and which should never suffer a particle of the water 
 to enter the vessel ! " Reflect how frequently we swal- 
 low, how constantly we breathe. In a city feast, for 
 N 2 
 
150 ALIMENTARY ORGANS. 
 
 example, what deglutition, what anhelation, yet does 
 this little cartilage, the epiglottis, so effectually inter- 
 pose its office, so securely guard the entrance of the 
 wind pipe, that whilst morsel after morsel, draught after 
 draught, are coursing one another over it, an accident 
 of a crumb, or a drop slipping into this passage (which 
 nevertheless must be opened for the breath every se- 
 cond of time) excites, in the whole company, not 
 only alarm by its danger, but surprise by its novel- 
 ty. Not two guests are choked in a century." 
 
 B. This is the more wonderful, because the pas- 
 sage into the lungs is often continued •open for an un- 
 usual length of time, as in the act of gaping. This 
 must add to the danger, if we should happen to be 
 swallowing at the same time. 
 
 A. It is said this danger is not permitted, for 
 that the muscles employed in swallowing are so cu- 
 riously connected with those necessary to produce 
 a wide extension of the mouth, that the two acts 
 cannot be performed together. 
 
 T. In passing in this manner from example to 
 example of creative goodness and skill, I feel con- 
 stantly, my young friends, the necessity of reminding 
 you that the proofs of an intelligent and designing 
 beneficence are not confined to selected cases. In 
 taking a cursory survey, we notice those instances 
 which may be most easily explained. But I trust 
 you will be sensible that an equal wisdom pervades 
 the whole system of Creation ; and that seeing par- 
 ticular demonstrations will tend to confirm this devout 
 conviction in your minds. 
 
NATURAL THEOLOGY. 151 
 
 B, I presume a benevolent providence appears in 
 adapting the structure of the throat to the wants of 
 different animals. 
 
 T. Yes, there are many instances in which there 
 seems to be an extraordinary organization of this 
 part of animals to answer particular purposes. 
 Among the most curious is that of the sea turtle. 
 I hardly know an instance in which the care of the 
 Creator is more distinctly seen than in the novel pro- 
 vision made for this animal. The whole cavity of 
 the throat is hung round with a great number of little 
 pendants resembling in form the bobbins employed in 
 making lace ; the lower extremities of which are fur- 
 nished with a sharp point, so that they prevent the 
 ascent of any thing solid, while they permit a free 
 passage to liquids. This singular structure is mar- 
 vellously contrived for the particular wants of thi^ 
 animal. As in their mode of swallowing, they often 
 admit great quantities of water into their mouths, 
 this provision enables them to regurgitate, or throw 
 back, the superfluous liquid, without permitting the 
 fishes and other marine substances on which they live 
 to escape with it. ' 
 
 HUMAN VOICE 
 
 A. The HUMAN VOICE has been pronounced by 
 a devout writer, " the greatest masterpiece of the 
 Creator. ^^ 
 
 It is by the air passing from the lungs through the 
 little orifice termed the glottis, that the voice is 
 
152 THE VOICE. 
 
 formed. In all other wind instruments it is necessary 
 to have different pipes or orifices to produce different 
 notes. But the wonder of the mechanism of the glottis 
 is, that, from one and the same aperture, arise all the 
 various modulations of which the human voice is ca- 
 pable. 
 
 The power of voice and language is not however, 
 confined to the human species. A kind Providence 
 has bestowed this means of communication upon oth- 
 er animals, so far as is necessary for them — and every 
 one must be sensible they would labor under great 
 privations, if they were incapable of some language 
 to make known their wants, which they could not 
 do in a variety of cases, as at remote distances, or 
 in the dark, without the assistance of sound. 
 
 " Observe the different cries of the cock,^' says 
 a lively German writer, " either when a dog, or 
 a stranger enters the yard, or when a hawk, or some 
 similar bird of prey, presents itself, or when he calls 
 to or answers his mates. What mean those lamen- 
 table cries of the turkey 1 Behold her chicks, all on 
 a sudden concealing themselves, and lying so quiet, 
 that one would think they were dead. The mother 
 looks upwards, and her anxiety is increased ; but what 
 does she see ? a black point scarcely distinguishable, 
 but which proves to be a bird of prey, which could 
 not escape her vigilance. The bird of prey disap- 
 pears, and the hen sets up a cry of joy. The language 
 of the dog is so copious, various, and expressive, that 
 it would be almost sufficient to fill a dictionary. 
 
NATURAL THEOLOGY. . 153 
 
 Here again we may admire the wisdom and good- 
 ness of the Supreme Being. What kind attention has 
 he shewn toward animals, in giving them the power 
 to express by sounds their wants and feelings. From 
 their organization, and the nature of their minds it 
 was impossible they should speak the language of 
 man ; but they would have been much to be pitied, 
 and less useful to us, had the Creator entirely deprived 
 them of the power of making themselves understood. 
 God has given them proper organs to produce and 
 vary a certain number of sounds ; and such is their 
 make, that each has particular and distinct sounds, 
 by which they make themselves understood. In short, 
 the Creator has given such force to the language of 
 animals, as their nature would admit of, and all that 
 was necessary in order for them to answer the' end for 
 which they were designed. 
 
 T. You say, the language of animals. 
 
 A. The voice of animals is not, strictly speaking, 
 the same with language. By language is properly 
 understood articulate sounds expressive of definite 
 ideas, not natural, but acquired. This is the prerog- 
 ative of man ; though man at the same time partici- 
 pates with all other animals in being capable of express- 
 ing his wants and passions by natural and inarticulate 
 cries. Here again we discover the wisdom and good- 
 ness of the Creator. The infant is enabled to make 
 known its wants, and the mother to express her affec- 
 tion by this gift of na!ure, long before any power of 
 communication has been formed by articulate lan- 
 guage. Herder terms the natural voice the speech 
 
154 .THE VOICE. 
 
 of the father and mother, the child and friend ; and 
 beautifully suggests that it forms a necessary means 
 of cultivation in the first stages of life. It establishes 
 an intercourse between the parent and offspring, 
 when no other could be made. Its utility to us on a 
 variety of occasions opens a wide field for acknowl- 
 edging the kind purposes of Providence in endowing 
 us with this faculty. A child sinking in the water or 
 attacked by a furious animal is not left to depend up- 
 on such assistance as he may be able to command by 
 being sufficiently near and sufficiently collected to dis- 
 cribe his danger. God has given a voice to fear more 
 prompt and effectual than language. It is observ- 
 able that he has imparted to distress much more pow- 
 er in this respect than to any other class of our emo- 
 tions. We rush mechanically to the cry of pain and 
 terror. He has given a language to misery to which 
 every bosom responds ; and we see the beneficence 
 of this distinction. It shews the evident purpose of 
 a kind Creator. The misery of others requires our 
 attention, but their happiness does not. 
 
 T. It seems unnecessary to ask what demonstrations 
 of design are discoverable in any other part of the 
 living economy, after all we have perceived of the 
 Creator's wisdom and beneficence in those which 
 have been noticed. But we will take a cursory view 
 of some of the principal which remain. Next to th e 
 wonderful mechanism of the parts you have described, 
 is the great chemical laboratory, or the chief alimen- 
 tary organ of the system, the stomach. 
 
NATURAL THEOLOGY. 155 
 
 THE STOMACH. 
 
 A. The stomach is the organ in which the ahment 
 is finally received, and where it waits to undergo a 
 great chemical action, which consists in converting it 
 into a pulpy substance, preparatory to its distribution 
 to every part of the body. What may be first notic- 
 ed, in view of wisdom and design, is the form and 
 situation of this curious organ. It is placed in the 
 centre of the cavity of the body, with its length across 
 the body, and curving down in the middle, thus en- 
 abling it the better to receive and hold its contents. 
 
 Fig, 29. 
 
 In this plate of the stomach, it will be seen that the delivering ori- 
 fice is situated in the most favorable manner for the purposes 
 of the organ. Had it been placed below, nothing could have 
 been retained. 
 
 T. Are there any remarlcahle varieties of the 
 stomachs in different animals ? 
 
 A. In some animals which are destitute of teeth, 
 this organ possesses the power of a mill, to perform 
 the operation of- bruising and grinding their food. 
 
156 
 
 DIGESTION. 
 
 This is the case with fowls and birds. — The giz- 
 zard is, in effect, their stomach ; and in some birds it 
 is capable of grinding the hardest substances, with 
 the assistance of a liquor nature has provided in it. 
 The gravel, which makes a part of their food, is to 
 assist the operation of this mill. 
 
 B. This explains the marvellous stories related of 
 the ostrich. — There was an account not long since, of 
 one whose stomach was found quite full, among other 
 articles, of such indigestible materials as old nails, 
 glass, and brass buttons, which were partly worn 
 away by the friction of the organ. 
 
 A. The camel, to enable it to traverse the sandy 
 desarts of the countries in which it lives, is kindly 
 furnished with an extraordinary kind of stomach, 
 which answers among other purposes that of a water 
 vessel, in which it can carry its drink. There are 
 several little muscular cisterns attached to the stom- 
 ach of the animal, which are kept separate, and which 
 it fills from time to time as opportunities serve. The 
 main stomach has, (principally on one side,) rows 
 of purses or cells, side by side, with their mouths 
 upwards, in length from six to nine inches, which 
 are capable of admitting one's hand, and of holding 
 from one pint to a quart of water or more. These 
 purses or cells are numerous, and capable of holding 
 when much distended, nearly thirty gallons of water. 
 When the creature is thirsty the stomach contracts, 
 and the water flows over the tops of the cells into the 
 main stomach, to moisten the dry food, and help di- 
 gestion. The greater the quantity of food there is in 
 
NATURAL THEOLOGY. 157 
 
 the Stomach, (of course the lateral pressure on the cells 
 will be greater,) the more water will be forced from 
 the purses or cells, and more is required to moisten 
 the quantity of dry food. The mouths of the cells are 
 too sensible of excitement, to admit any coarser nu- 
 triment than water. The fodder is never found in 
 the cells unless the animal has been much tumbled 
 after death, which readily accounts for the possibility 
 of taking pure water from the stomach of the camel 
 thirty days after the water is taken in. Their food 
 once masticated and swallowed, is returned to the 
 mouth, and there broken finer ; its weight being in- 
 creased by diminution of bulk, it easily passes by the 
 coarser and lighter food into the stomach, and is 
 pressed into the intestine for further digestion. 
 
 The ox is a still more curious instance of the di- 
 versity which Providence has kindly introduced in 
 the structure of the stomach. This animal, and seve- 
 ral other species of quadrupeds, have four stomachs, 
 and are enabled in consequence to perform the singular 
 process of rumination, or, as it is called, chewing the 
 cud. It consists in repeating their mastication at a 
 considerable interval after eating. These animals are 
 deficient in upper front teeth ;, this circumstance, to- 
 gether with that of the peculiar toughness of the fib- 
 rous substances on which they live, and the great 
 quantity they have to gather of such light and un- 
 nutritious food, render it a most happy provision by 
 which the goodness of Providence has distinguished 
 them, that they are able to collect their nourishment, 
 o 
 
158 DIGESTION. 
 
 and afterwards finish the process of mastication at 
 their convenience. It is received in the coarse state 
 into the first stomach — and, after being masticated 
 anew, passes successively into the others. The little 
 pellets we see them throwing up into their mouths 
 every few minutes, when they are lying down, are 
 the forage they are quietly and leisurly taking up from 
 the receptacle which they had been employed in re- 
 plenishing. 
 
 T. Among all the curiosities of this organ, how- 
 ever, you have said nothing of the wonderful agent 
 by which, principally, our food is digested. 
 
 A. The food is converted into a soft pulpy sub- 
 stance, chiefly by means of a chemical liquor called 
 the gastric juice, which is continually secreted from 
 the inner membrane of the stomach. It dissolves the 
 contents of the stomach with astonishing rapidity. 
 Soft and hard, flesh and vegetables, equally yield. 
 The most solid bones cannot withstand its action. 
 
 J?. I cannot conceive how it can be safe to have 
 a liquid in our stomach, which is so very powerful as 
 to dissolve bones and flesh ; for the stomach itself \s 
 flesh, and one would think it would dissolve this also. 
 
 A. So any one would naturally imagine. We 
 only know it will act upon dead, but not upon living 
 flesh. Why this distinction — what produces it — ^is 
 yet a secret. No chemist would think of pouring a 
 liquid upon his hand, sufficiently powerful to dissolve 
 a bone in the course of a few hours, without expect- 
 ing his flesh would be instantly consumed. Within all 
 the compass of his art, he knows of no chemical sub- 
 
NATURAL THEOLOGY. 159 
 
 Stance with which it could be done in safety. He has 
 no acquaintance with any such agent, that alone ex- 
 cepted which is found in the living animal. 
 
 B. What a succession of wise and benevolent 
 provisions ! It is well we have adopted some me- 
 thodical view of the animal structure ; for otherwise 
 it would have been impossible to have remembered a 
 hundredth part of all these wonderful facts. So many 
 were unknown to me, that I am sure I shall always in 
 future entertain a stronger sense of the power in which 
 we live^ and move, and have our being. 
 
 T. You may deem it an inestimable acquisition, 
 if, by the attention you have given to this subject, 
 you are impressed with but one additional evidence of 
 the wisdom and goodness of our adorable Creator. 
 Any study that should have this effect — to cultivate 
 a single conviction of his agency — is surely the no- 
 blest to which our minds can be directed. " In ex- 
 plaining these things," says an ancient Greek physi- 
 cian, " I esteem myself as composing a solemn hymn 
 to the great Architect of our bodily frame ; in which, 
 I think, there is more true piety, than in sacrificing 
 hecatombs of oxen, or in burning the most costly per- 
 fumes." 
 
 But to finish our survey of the apparatus which re- 
 lates to nourishing the body. 
 
 A. After the food has been brought into a proper 
 state by the chemistry which nature has provided in 
 the stomach ; this organ, by a tremulous, undulating 
 motion, empties its contents thus altered, into another 
 passage, leading from the stomach ; where another 
 
'60 HEART. 
 
 chemical substance is added, called the 6^7e, which 
 forms a still further process in this curious manufac- 
 ture. It is then carried in its descent to the mouths 
 of innumerable little tubes, called lacteals, from a 
 Latin word signifying milk, which opening along in 
 the surfaces of the intestines, suck up the milhy fluid, 
 into which the nutritive part of every substance we 
 eat is alike converted in a short time by the inexpli- 
 cable powers which Providence has assigned to the 
 digestive organs. It hence makes its way by other 
 vessels into the great current of the blood, by which 
 it is distributed into every nook and corner of the sys- 
 tem ; and thus, what we receive with our mouth, ar- 
 rives in a few hours at our fingers^ ends. 
 
 THE HEART. 
 
 T. You now come to a most noble part of the 
 frame — the engine by which the blood, containing 
 the nutriment, is circulated over the body. You 
 have reached what may be termed the mainspring 
 of the animal structure. " The wisdom of the Cre- 
 ator, ^^ saith Hamburgher, ^^ is in nothing seen more 
 gloriously than in the heart ; " though, strictly speak- 
 ing, it is difficult to pronounce what part of the sys- 
 tem is most essential ; for it all acts together as one 
 
NATURAL THEOLOGY. 161 
 
 perfect and connected whole. You may describe the 
 heart. 
 
 A» The ^ear^/with its connected machinery the 
 arteries and veins, is the immediate contrivance by 
 which the blood is distributed. It is as perfectly 
 artificial as any machine whatever for conducting or 
 forcing water. The arteries are the blood vessels 
 which convey the blood from the heart to every part 
 of the body. The veiiis are the vessels by which it 
 is collected and returned ; while the heart is the en- 
 gine which is continually throwing it out in one di- 
 rection and receiving it in another. 
 
 T. How is all this performed ? 
 
 A. The heart is a hollow muscle, divided off 
 into several rooms, — and is made upon the principle 
 of a fire engine. 
 
 T. You have mentioned a striking comparison. 
 We have found almost every kind of apparatus in the 
 human frame ; — but one would hardly have thought 
 of hearing of a Jire engine, 
 
 B. I believe it is not an imaginary resemblance, 
 however. 
 
 T. By no means : there is a most extraordinary 
 similarity ; and to evince the wisdom of the Creator 
 more perfectly, and observe how exactly one of the 
 most ingenious productions of art has been anticipated 
 in the living structure, you may describe a^re engine. 
 
 A. A fire engine requires, in the first place, to 
 have a room to recieve the water, which in the best 
 engines, is carried to it by a hose or leathern tube. 
 o2 
 
16^ 
 
 CIRCULATION OF THE BLOOD. 
 
 From this room, the water runs immediately through 
 a little hole into a second room, called the farcing 
 room, where it is forced out in a stream by simply 
 applying a powerful pressure upon it. The water 
 cannot run back again from the forcing room into the 
 receiving room, when the pressure is applied, because 
 there is a little valve or door placed over the hole. 
 The door, swinging inward into the" forcing room, is 
 immediately crowded to and shut by the water, when 
 it would endeavor to escape, as the forcing com- 
 mences ; and the water is therefore compelled to fly 
 out into the hose or pipe provided for it. But when 
 the forcing ceases, the door opens and' lets in more 
 water, — and so on continually. Such is a descrip- 
 tion of a fire engine of the simplest kind. There are 
 two of these engines in the heart ; each having its 
 receiving and forcing rooms, with its little door be- 
 tween them ; and each having its hoses to receive 
 the blood and to convey it where it is required ; 
 making four rooms in the whole, and the heart being 
 divided off into four apartments for that purpose. 
 With one engine, the blood is received from every 
 part of the body by two hoses of veins which termi- 
 nate each in a single pipe, where they enter the 
 heart. By another hose, which is termed an artery, 
 the same engine forces all this blood into the lungs, 
 where it has to undergo a certain change from the 
 air. The second engine] in its turn, now receives 
 the blood from the lungs by other hoses of veins ; 
 and again by another arterial hose distributes it over 
 the whole system ; whence it is returned to |he heart, 
 
NATURAL THEOLOGY. 
 
 163 
 
 to go over the same process of being first received 
 from the body and propelled into the lungs, — and 
 then received from the lungs and propelled into the 
 body, by two separate engines, as long as life shall 
 last. 
 
 Fig. 30. 
 
 A Fire Engine of the simplest construction. 
 
 a, the receiving hose emptying the water into b, the receiving 
 roQm, — whence it passes into tZ, the forcing room, through e, 
 a little orifice with a valve or clapper over it, opening into 
 the forcing room, the valve shutting down and closing the 
 orifice, when the forcing instrument g^ d, descends. The 
 water is then forced out into/, the delivering hose, through e, 
 another little orifice -w^th a valve over it, which opens into 
 the hose, and prevents the return of the water into the forcing 
 room. The dotted line represents the course of the water. 
 
164 CIRCULATION OF THE BLOOD. 
 
 Fig. 31. 
 
 A view of the heart, showing its resemblance to a fire engine. 
 C 
 
 d 
 
 a 
 
 B, A, C, D, the four rooms in the heart, i, a, c, (Z, four principal 
 veins and arteries conveying the blood to and from the heart, 
 — (the dotted lines representing the course.) 
 
 6, a vein bringing the blood from the body into B, the first receiv- 
 ing room, called the right auricle ; whence it passes into A, 
 the first forcing room, termed the right ventricle. — A small 
 valve is represented playing over the orifice, and opening into 
 the forcing room, to prevent the return of the blood, exactly 
 as in the fire engine, a, the artery by which the blood is 
 thrown into the lungs, c, the valve opening into this artery, 
 and preventing the return of the j^lood, the same as in the en- 
 gine. 
 
 — Again — 
 
 c, a vein by which the blood is returned from the lungs, and de- 
 livered into C, the second receiving room, called the left au- 
 ricle ; whence it passes into D, the second forcing room, term- 
 ed the left ventricle ; and hence into <Z, the great artery which 
 distributes it over the body. The valves — the same as in the 
 other rooms. 
 
 N. B. The situations, shapes and dimensions of the different 
 parts are not exactly observed in the figure. In the heart, the 
 auricles B, C, have more than one ^ein. The valves are also 
 differently shaped from those in the figure. But the leading 
 principles are seen ; sufficient to show that, in construction, 
 the heart is literally a double fire engine. 
 
NATURAL THEOLOGY. 165 
 
 T. What ivories all this machinery ? 
 
 A. Each room of the heart seems to work itself. 
 — The sides alternately contract and expand like a 
 bellows ; so that the cavities are continually filling 
 and discharging. The cause is unknown ; though 
 some think it is owing to a peculiar quality of the 
 blood. 
 
 T. In Jire engines there is a body of compressed 
 air, which is so contrived as to press the water out ; 
 because the stroke of the pump, w^hich is only by 
 jerks 3 would not be capable of producing a steady mo- 
 tion. Is there any corresponding contrivance in the 
 heart, since here too the strokes are only by in- 
 tervals ? 
 
 A. It is stated, that the arteries which receive 
 the rush of the blood from the heart are made elastic ; 
 this being the case, they enlarge when the blood is 
 thrown into them, and as soon as the discharge cea- 
 ses, contracting by their own spring, they press the 
 blood along in its course ; that is to say, they answer 
 the same purpose as the air vessel in the engine. 
 
 B, One feels disposed to stop after this desrcip- 
 tion of the heart ; for it is impossible there can be 
 any thing so wonderful in any other part of the body, 
 as the mechanism you have described. 
 
 T. We express our surprise at finding means em- 
 ployed in the living structure resembling our own 
 contrivances. But if they are such as would best 
 answer the purpose, what else could we expect to 
 find in the works of a Divine Architect ? But before 
 you have quite done with the circulating system, you 
 
166 
 
 CIRCULATION OF THE BLOOD. 
 
 must notice the care and solicitude with which the 
 blood vessels are in many cases disposed. 
 
 A. A wound in an artery would be much more 
 dangerous than in a vein ; because the blood rushes 
 in the arteries with much greater force than in the 
 veins, which only return the blood to the heart. It 
 hence affords a striking evidence of a designing Prov- 
 idence, that the arteries lie deeper than the veins ; 
 and, where particularly exposed, run along in a 
 groove or a channel cut into the very hone. In the 
 hands they pass down hetwcen the fingers, so that the 
 familiar accident of a cross cut in- the finger, can 
 never separate one of them witliout cleaving the bone. 
 How came these vessels to take a course so secure 
 and defended ? What led them, more than the veins, 
 to shun exposed situation, where they would have 
 been liable to injury ? We know no other cause than 
 an Intelligence which perceived the danger to be 
 avoided. 
 
 B. A kind provision for heedless children ! 
 
 T. Kind for every one ; as no parts are so liable 
 to be wounded as the fingers. 
 
 A. As the veins, which are the vessels that return 
 the blood to the heart, that is, all below the heart, 
 have to ascend, — the blood has to mount in a direc- 
 tion opposite to that of its weight. Here, therefore, 
 is the danger of a rejloiv — or a tendency contrary to 
 the true circulation. Now, the universal provision 
 against the flowing of water in a direction opposite to 
 that desired, is a valve ox flood gate. It is the same 
 in the present instance. There are a great number of 
 
NATURAL THEOLOGY. 167 
 
 little skins or thin membranes lying close down to the 
 side of the vein, at suitable distances, and which allow 
 a free passage to the stream when it pursues its ascend- 
 ing course, but thrust out and bar up the passage 
 by the fluid getting behind them, whenever it would 
 attempt to flow the other way. 
 
 B. Are there not the same valves in the vessels 
 which convey the blood from the heart ? 
 
 A. There are not : except one at the mouth of 
 each artery which takes the blood from the heart. 
 There are none stationed along in these vessels as in 
 the veins ; and they would have been of no use, as 
 there is no danger of a reflux of the blood in its pas- 
 sage from the heart. 
 
 B. What endless exam*ples of an all contriving 
 wisdom ! If one should attempt to account for the 
 formation of these loose skins or valves, by supposing 
 the force of the blood might have raised them up from 
 the sides of the vessels, they must, according to this 
 explanation, have been numerous in the arteries, 
 where the strength of the current is the most power- 
 ful ; but we find there are none. The operation of 
 natural causes seems to be exactly reversed in this, 
 as in many other parts of our wonderful structure. 
 
 T. There is one part of the apparatus concerned 
 in the circulation of the blood, which you have omit- 
 ted, viz. the lungs. You may briefly describe these ; 
 and we will take our leave of the interior of the 
 animal frame. 
 
168 LUNGS. 
 
 THE LUNGS. 
 
 A. The LUNGS are two large spongy substances 
 which fill the upper part of the chest, and are admir- 
 ably fitted for the purpose they answer, viz. to 
 ventilate the blood, or afford it the air by which it is 
 purified and rendered fit for the support of life. 
 
 B. I thought you were going to say, for the pur- 
 pose of breathing. 
 
 A. It is the same thing. The principal use of 
 breathing is the introduction of air for the benefit of 
 the blood ; — it being found, that the blood derives 
 some of its most essential properties from the air 
 which we inhale into the lungs. All the blood of the 
 body is, for this purpose, thrown up into the lungs by 
 the heart in the course of every circulation : — and here 
 we may notice the curious mechanism of the lungs. 
 They are full of air holes running in every direction ; 
 and the blood is exposed to the air in innumerable 
 vessels which are spread over the sides of these air 
 holes, for this purpose. — Again, what we find in no 
 other part of the body, these passages for the air are 
 made of a substance like horn : — this preserves them 
 open and free for the circulation of the air. How 
 comes it, we may ask, they are not made of the same 
 substance with the veins ? We can only answer by 
 referring to design. The hlood can force its way 
 through a sliin tube ; but air would be liable to ho. 
 obstructed. Lastly, there is a double passage for 
 
NATURAL THEOLOGY. 169 
 
 breathing ; — through the mouth, and by the nostrils. 
 But for the latter, we could not breathe without diffi- 
 culty, in taking our food. The infant would find it 
 impossible. 
 
 COVERING OF ANIMALS. 
 
 T. You have now taken a general survey of tht 
 internal structure. You may close with a brief ac- 
 count of the admirable covering with ivhich the 
 whole is invested. 
 
 A.. The skin is a protection from the air, which 
 we know from experience, would occasion insup- 
 portable suffering, if it were immediately in contact 
 with the flesh. For this and other purposes, there is 
 a three-fold provision : there are three skins. The 
 first, called the epidermis, or scarf skin, possesses 
 no feeling, and covers the body, like a glove. It is 
 this skin which is raised by a blister. The next is 
 the seat of the color ; — ^in Africans black, — in the 
 European, white, &c. This is called the rete mu- 
 cosum. Last of all, is the true skin ; the anatomical 
 •expression is cutis, which in Latin signifies skin. 
 
 T. Another use of the sJcin is to prevent the 
 hody from being overheated,, and to preserve an 
 equal temperatiire in the system. 
 
 B. This must be some extraordinary contrivance. 
 
 A. There are innumerable little orifices, termed 
 pores, m every part of the skin, though invisible to 
 p 
 
l70 COVERING OF ANIMALS. 
 
 the naked eye, through which a thin, watery liquid is 
 continually issuing, called the sweat, when percepti- 
 ble to the senses ; — at other times, the insensible 
 perspiration. If our sight was sufficiently keen, we 
 should see every person in health, surrounded with 
 a cloud of vapor. 
 
 B. But still, how is this to prevent the body from 
 being overheated ? 
 
 A. Upon a very simple principle, which is here 
 beautifully introduced. If we wet our finger and 
 hold it in the air, we are sensible . of an immediate 
 coolness in the finger. It is because the heat escapes 
 with the moisture, as the finger dries ; and the 
 t[uicker we dry the finger by waving it in the air, the 
 greater the coolness produced. The constant evapora- 
 tion or drying up of the perspiration of the skin has the 
 same effect ; — and hence the danger of sitting by an 
 open window, or in a current of air, when the per- 
 spiration is free. 
 
 B. This brings into view a new kindness of 
 Providence, that the more the body is heated by 
 weather or exercise, the more moisture is thrown out 
 upon the surface. The Jire becomes its own extin- 
 guisher. We now understand also how those marvel- 
 lous accounts may all be true, of persons setting in 
 hot ovens without being burned. The profuse perspi- 
 ration prevents the efiects of the heat. 
 
 T. Do we discover any striking varieties in the 
 coverings of different animals ? 
 
 A. "The human animal is the only one which is 
 naked, and the only one which can clothe itself. 
 
NATURAL THEOLOGY. 171 
 
 This is one of the properties which renders him an 
 animal of all climates and of all seasons. He can 
 adapt the warmth or lightness of his covering to the 
 temperature of his habitation. Had he been born 
 with a fleece upon his back^, although he might haye 
 been comforted by its warmth in high latitudes, it 
 would have oppressed him by its weight and heat, as 
 the species spread toward the equator. What art 
 however does for men, nature has in many instances 
 done for those animals which are incapable of art. 
 The clothing of its own accord changes w^ith their 
 necessities. This is particularly the case with that large 
 tribe of quadrupeds which are covered with furs. 
 Every dealer in bare skins and rabbit skins, knows 
 how much the fur is thickened by the approach of 
 winter. It seems to be a part of the same constitu- 
 tion and the same design, that wool, in hot countries, 
 degenerates, as it is called, but in truth (most happi- 
 ly for the animaVs ease) passes into hair ; whilst, on 
 the contrary, that hair in the dogs of the polar re- 
 gions, is turned into wool, or something very like it. 
 To which may be referred what naturalists have re- 
 marked, that bears, wolves, foxes, hares, he. which 
 do not take the water, have the fur much thicker on 
 the back, than underneath ; whereas, in the beaver, 
 it is the thickest beneath, as are also the feathers in 
 the water fowl. We know the final cause, the use 
 and benefit, of all this ; and we know no more. 
 
 T. Wbat is there remarkable in the covering of 
 birds ? 
 
172 COVERING OF ANIMALS. 
 
 A. On account of its peculiar lightness, smooth- 
 ness, and warmth, it is singularly adapted to the uses 
 of the animal. A bird's wing is a mechanical won- 
 der. It may be doubted whether the most ingenious 
 artist would have hit upon the construction, till he 
 had seen it exemplified. He would have known there 
 should be something to spread out, and be capable of 
 folding up, and that it should be very light, and suffi- 
 ciently strong, at the same time, to make a stroke 
 upon the air. The probability is, he would have 
 thought of a thin membrane like a piece of cloth, 
 so contrived as to open and shut like a fan, which is 
 actually the plan which has been adopted in artificial 
 wings. But there must be one unavoidable imperfec- 
 tion in such a wing. If accidentally torn, it would 
 be ruined for the bird's use. This difficulty is avoided 
 in the bird's wing by the only imaginable contrivance 
 which could have answered the purpose ; and that 
 Is, having the wing composed of distinct feathers, suffi- 
 ciently close, when united, to give the necessary stroke, 
 but separating in case of any uunsual violence that would 
 endanger a membrane, and then recovering their places 
 by their own elasticity or springiness. Such is the struc- 
 ture of a hird^s wing. Its ingenuity will still further 
 appear, when we examine a single feather. If the 
 beard or vane of a feather, that part we usually strip 
 off when we make a pen, be stroked down toward the 
 follow or quill part, we find the little filaments or 
 threads will stand out from the stem, and remain sep- 
 arate ; but if they are smoothed back in their places 
 ^hey will reunite and become fastened together with 
 
NATURAL THEOLOGY. 178 
 
 considerable force. They thus admirably answer 
 the purposes of a wing ; for when parted by any vio- 
 lence which would have torn^ instead of rumpling 
 them, had they not been separate, the bird can re- 
 place them with a feiu stroTces of his bill. 
 
 B. This explains why we see birds often so dili- 
 gently engaged in stroking an oily substance over 
 their feathers. It probably contains something glu- 
 tinous to hold the filaments together. 
 
 A. We know of nothing glutinous which the 
 weather would not harden or melt. It must be some 
 mechanical contrivance ; and so it is. Between 
 every two filaments there are little hooks ; on one 
 filament curving up, and on the other, down, so as 
 to catch over and fasten together, like the latch of 
 a door. 
 
 In the feathers of the ostrich, this apparatus is 
 wanting, and the consequence is easily seen ; the 
 filaments hang loose and form a sort of down merely, 
 well adapted for the purposes of a fan, or for an orna- 
 ment, but which would certainly have been an imper- 
 fection, had the bird, which it is not, been adapted 
 for flight. 
 
 In the body feathers of all birds the lower filaments 
 of the feather are not clasped together, but are mere 
 furze or down. The clasps are confined to the upper 
 part of the vane. We find, upon examination, that 
 from the place where the clasps are discontinued and 
 the do\vny part commences, the feathers are overlap- 
 ped by the feathers behind like the shingles upon 
 a house, and that the clasps are not wanted here for 
 p 2 
 
174 COVERING OL ANIMALS. 
 
 the purpose they answer, where the feather is expo- 
 sed to the water or ah-, viz. to produce a smooth, 
 co'nnected surface, — while the down in this under 
 situation, is more useful* for the warmth of the bird. 
 
 The body feather of a bird, exhibiting the discontinuance of the 
 clasps at the lower part of the stem. - 
 
 B. What a striking and beautiful design ! If the 
 clasps had been produced by a set of causes, consti- 
 tuted by accident, and acting as all ignorant causes 
 must act, by a general operation, then we are at lib- 
 erty to ask, why the apparatus was discontinued only 
 at this part of the feather, where the occasion for it 
 ceases, or where the feather is covered ? What 7iatu- 
 ral tendency could there be in covering the feather 
 to prevent the formation of the little hooks ? We see 
 a regard to utility, and can give no other solution. 
 
 T. Did you ever notice another curious circum- 
 stance in this remarkable structure ? 
 
 A. The filaments are broad and flat, like the 
 sticks of a fan. Owing to this circumstance, they 
 easily bend for the approach of one another, whilst 
 in the other direction they bend with difficulty. 
 Now, it is observable, that it is in this latter direction, 
 the feathers strike upon the air and in which, conse- 
 
NATURAL THEOLOGY. 175v 
 
 qtiently, the greatest strength and power of resistance 
 are wanted. 
 
 Also, the quill part is a curiosity. It consists of 
 two sets of fibres, the one running lengthwise, which 
 are those we separate when we make a pen ; and 
 the others passing around the quill, like" the ferrules 
 upon a cane, or the hoops upon a barrel. The rings 
 secure the quill from being split. The hoops are 
 a security to the staves. Hence it is, we are obliged 
 to scrape a quill before we can get a split. We must 
 in fact unhoop the barrel. 
 
 B. How many kinds of arts we have had exem- 
 plified in the living machine ! Here, it seems, we 
 have that of the cooper. — Speaking of the the cover- 
 ing of animals, is there any design, we can perceive, 
 in the difference of color 1 
 
 A. It is found, that heat will not escape so easily 
 through a white surface. The colors of animals in 
 very cold countries are remarkably inclined to white ; — 
 and animals are apt to become of this' color, when 
 removed to a high latitude. We can assign no other 
 reason for this, but a beneficient appointment of Provi- 
 dence, for the comfort of the animal. The natives of 
 hot countries, on the contrary, are more or less of a 
 dark complexion. 
 
 B. But does not black absorb the heat, or, as is 
 commonly said, draw the sun ? and must it not there- 
 fore be an uncomfortable color, in those regions ? 
 
 A. There are some recent experiments which 
 seem to shew that a black color will protect the skin 
 from the scorching effects of the sun's rays ; and it '- 
 
176 COVERING OP ANIMALS. 
 
 well known it will cool quickest in the shade. The 
 African, therefore, derives a double benefit from his 
 color in his own climate ; though, in a different situ- 
 ation, the provision would cease to be beneficial. We 
 see hfere another violation of nature in his* removal. 
 
 T. Having spoken of several particulars in which 
 the wisdom and goodness of the Creator are exhibit- 
 ed in covering and protecting the body with an evi- 
 dent accommodation to the wants of men in different 
 situations, and to the peculiar circumstances of dif- 
 ferent animals ; — we will close our observations of 
 an anatomical kind, by glancing at one further mark 
 of Divine goodness, viz. in the remedies naturally 
 provided. 
 
 A. There are few cases in which prospective 
 contrivance is more conspicuous; or in which we 
 have more occasion to admire the providence of God, 
 and his tender care for our preservation. One of 
 the most striking is the provision for the union of broken 
 bones. From the situation and structure of the bones 
 if they are broken, the injury must be irreparable, un- 
 less theys hould be capable of taking the cure princi- 
 pally upon themselves. The whole thickness of the flesh 
 would have to be separated in the first instance ; and 
 then how to unite them, if this was to be a business 
 of ours, would surpass our ingenuity. The provision, 
 as is well known, consists in there oozing out from 
 the broken extremities of the bone a soft fluid matter 
 that soon turns into bone, and unites them together 
 more firmly than before the fracture. 
 
NATURAL THEOLOGY. 177 
 
 B. Just as in cementing a vessel, we apply some 
 liquid substance which hardens and unites the parts ; 
 — except, that in the present instance, the uniting 
 matter is supplied hy the fracture itself; another of 
 the innumerable instances in which our contrivances 
 are but a rude and imperfect imitation of those which 
 creative skill has employed in the human structure. 
 
 A. With regard to the union of bones, there are 
 several exceptions, singularly observable and remark- 
 able as evidences of design. There are some bones 
 in which when broken, true bone is never formed anew 
 to repair the injury^ as is the general provision. When 
 the arm is fractured, a bony matter exudes from the 
 extremities, which finally surrounds them completely 
 with a ring of bone. But when a piece of the sT^ull 
 is removed, no new hone is produced ; nothing but 
 a skinny or ligamentous substance is formed to fill the 
 opening. So, when the Icnee pan is fractured, the 
 pieces are always united in the same way. In either 
 of these cases, if bone or callous was formed, with 
 its ordinary irregularity of shape, — ^with a projecting 
 ring over the fracture the cavity of the skull, or knee 
 joint would be encroached on, and the most serious 
 evils would ensue. Why the power of creating new 
 substance like itself, should be denied to the skull and 
 the knee pan alone, we can only explain by referring 
 to an Architect who perceived the necessity of these 
 exceptions. 
 
178 
 
 COVERING OF ANIMALS. 
 
 Fig. 33. 
 
 The principal bones of the human frame, referring to former 
 descriptions. 
 
 T. You have now taken a general survey of some 
 of the principal marks of design and wisdom in our 
 frame. You have seen one diversified exhibition of 
 skill, far exceeding though strikingly analogous to 
 some of the most ingenious contrivances of human 
 
NATURAL THEOLOGY. 179 
 
 art. Whoever should refuse his conviction must be 
 incapable, it should seem, of trusting- to any conclu- 
 sion in any case. The subject has not been pursued 
 from any apprehension that you need to be confirmed 
 in the belief of a Creator ; but for the sake of im- 
 jpression; of multiplying the views which may lead 
 you to think of God ; and for the purpose of supply- 
 ing further opportunity of devout sentiment and medi- 
 tation. 
 
 It would now be proper to turn our attention to the 
 intellectual and moral faculties. The Natural The- 
 ology of the Mind, you may well suppose, cannot be 
 less replete with the indications of a wise and benefi- 
 cent Author than the physical structure. But this 
 must be reserved for another opportunity. There is 
 one connected subject, that o^ instincts, which may 
 be mentioned. 
 
 INSTINCTS 
 
 A. We behold the instinct of animals admirably 
 adapted to their different wants. In the bird, it is 
 a peculiar sagacity for building a nest, in the spider, 
 for spinning a web, in the bee, for forming a [honey 
 comb. The instinct is adapted to the nature of the 
 animal. Were they to exchange their instincts, it 
 would be fatal to them. The bird could not sit up- 
 on a web, or live in a honey comb. We have only to 
 consider the innumerable species of animals — and 
 
180 INSTINCTS. * 
 
 that every one has exactly the kind of instinct which 
 is suitable for it, and we must be sensible how plainly 
 it shows an all disposing wisdom and goodness. It 
 is no explanation to say, the body of the spider af- 
 fords a liquid which can be drawn out into threads, 
 and is suitable for making a web, and, therefore, the 
 insect employs the materials with which it iSnds itself 
 supphed. For what leads it to know how to employ 
 them, without instruction, as soon as it is born ? We 
 are therefore left to admire a striking display of 
 benificence and design in the distribution of instinct ; 
 that every animal is equally furnished with the par- 
 ticular species of sagacity which is suitable to its 
 wants. 
 
 Instinct forms one of the most pleasing and in- 
 structive parts of natural history, and one of the most 
 delightful studies to every mind that loves to trace 
 the beneficent care of the Creator? It is not confin- 
 ed to dumb animals j but we are to acknowledge the 
 goodness, which has given us instinct as well as rea- 
 son. It is by instinct infants manifest signs of fear 
 when they are approached with a countenance or 
 voice expressive of displeasure ; and are soothed 
 and pleased with gentle and tender expressions. We 
 have many instincts which the merciful Author of 
 our nature has given us, for a variety of occasions, 
 when the powers of reason are not unfolded, or cir- 
 cumstances would prevent them from answering our 
 purpose. Thus our preservation from danger often 
 requires, that some action should be performed so 
 suddenly that there is no time to think and determine. 
 
NATURAL THEOLOGY. 181 
 
 What could save a person, when slipping upon the 
 edge of a precipice, if he had no instinct to produce 
 a sudden exertion, but must first consider his danger 
 and wait the decision of his understanding 1 
 
 T. You may mention some examples of this re- 
 markable faculty in animals. 
 
 A. The honey bee, from the days of Virgil, lias 
 been celebrated for its sagacity in gathering its honey 
 and wax, in fabricating its comb, and in rearing its 
 young. But it has not till recently been discovered^ 
 that its works will bear such a critical examination of 
 the mechanic and mathematician. It is a curious ma. 
 thematical problem, what is the best manner of ma- 
 king a frame of bones laid side by side, and one upon 
 another like a honey-comb, so as to produce the great- 
 est strength, and the utmost possible saving of mate- 
 rials and labor ? It was seen, that each of the boxes 
 should be a figure of six sides, a hexagon. Such is 
 the form of the cells of the honey-comb. It was also 
 perceived, that the bottom of each box should not 
 stand exactly upon the top of the one underneath 
 that is, not rim upon rim, but that every box should 
 be placed so as to have three partitions meet on the 
 under side, forming a buttress to strengthen the bot- 
 tom. Such also is the structure of the honey-comb. 
 It was further demonstrated, that the bottom of each 
 box should not be a single plane or flat, like the bot- 
 tom of a bucket, but should consist of three pieces 
 making a spreading or obtuse angle with the sides of 
 the box and also with one another. Su^h agairi is 
 
382 INSTINCTS. 
 
 the construction of the honey-comb. But another 
 problem remained, viz : to determine the precise an- 
 gle at which the three pieces ought to be united tO' 
 render the structure perfect. " This is one of those 
 problems, belonging to the higher parts of mathemat- 
 ics, which are called problems of maxima and mini- 
 ma. It has been resolved by some mathematicians, 
 particularly by the ingenious Mr. Maclaurin, (one of 
 the most distinguished of the disciples of Newton) ^ 
 by a fluxionary calculation to be found in the Trans- 
 actions of the Royal Society of London. He has 
 determined the angle required ; and he found by the 
 most exact mensuration the subject could admit, that 
 it is the very angle in which the three planes in the 
 bottom 'of the cell of a honey-comb do actually 
 meet." 
 
 Another curious example of philosphical instinct is 
 the web of the spider. The web usually consists of 
 circular threads laid round upon straight ones which 
 form the stays that fasten it to the wall. The circu- 
 lar threads are covered with a glutinous substanc e, 
 and by these the food of the animal is caught. But the 
 straight ones, which are more necessary to the web, 
 are not adhesive, and are therefore not permitted to 
 grapple with the fly, so as to be exposed to the dan- 
 ger of being broken by its violence. The same is 
 true of the uttermost thread which encompasses the 
 web, and which is of particular importance to its se- 
 curity. This is not adhesive. The most skilful artist 
 could not have displayed more judgment. 
 
 T. Upon what grounds do you consider the in- 
 
NATURAL THEOLOGY, 183 
 
 stincts of animals as directly referrible to an immedi- 
 ate Providence ? 
 
 A. First, the very perfection of instinct shews 
 that the animal does not act from any sagacity and 
 reason of its own. If instinct is not to be ascribed 
 to a peculiar providential guidance ; if it is not a 
 blind propensity in regard to the animal ; a propensi- 
 ty prior to experience and independent of instruction ; 
 the bee has obtained a deeper insight into the princi- 
 f)le.s of mathematics, than most of our own species. 
 The early period at which animals discover their 
 instinct, not only evinces the care and goodness of 
 Providence, but that it is wholly an operation of 
 Providence. The chicken which is hatched in an 
 ^ven, and can have enjoyed no opportunity of learning, 
 is not ignorant how to provide for itself like others of 
 Its kind. '^ When caterpillars are shaken from a tree 
 in every direction, all of them immediately craul 
 toward the trunk and climb up, though they have 
 never formerly been upon the ground." They lose 
 no time in reasoning what they shall do. 
 
 B. But still, do not dumb creatures appear to 
 reflect and reason 1 I think it is Huber who mentions 
 that when bees discover that some neiv insect has been 
 depradating in their hives., they will soon contrive an 
 impediment to prevent it from entering a second time 
 If it is a broad bodied insect, they will narrow the 
 door. If a long and slender one, they will put up an 
 extra partition so very near the entrance, as not to 
 permit a body of that length to conform itself to the 
 passage. It is commonly said, I know not with what 
 
184 INSTINCTS. 
 
 truth, that if a dog, in pursuit of his master, arrives 
 at a place where three roads meet, he will scent only 
 upon two, without repeating the experiment upon the 
 third, as if he reasoned, that this of course must be 
 the right. 
 
 T. It would be unfortunate indeed, a very imper- 
 fect provision for the safety and comfort of the animal, 
 if instinct was incapable of adapting itself in any 
 measure to circumstances; if it had been so very 
 blind an impulse as not to have any discretion ; con- 
 fined to one invariable course ; and of no use in any 
 novelty of situation. But still this does not exalt in- 
 stinct to the rank of human intelligence^ by which 
 the Creator has placed an immeasurable distance 
 between us and the irrational animals. What seems 
 to be the limit of instinct ? 
 
 A. From all we see of instinct, it appears to re- 
 late principally to the preservation of the animal and 
 the continuance of the species. It enables the bird 
 to build its nest, and provide for its young. It is 
 a guide to the animal in given instances. Here it is 
 infallible : and here it ends. It may be a reasoning 
 faculty to a certain extent, as is often necessary, and 
 as therefore it might have been expected from the 
 benevolence of the Creator it would have been. Still, 
 whatever it be, it seems always to have been. We know 
 of no improvement in instinct. We discover no capaci- 
 ty of advancement ; no ability of self cultivation. 
 Society has done nothing, apparently, for the tribes 
 of instinct, as it has done for our species. The ani- 
 mals that herd together remain as much the same, 
 
NATURAL THEOLOOr. 185 
 
 from generation to generation, as the most solitary. 
 We discover no one inclining to become an instructer 
 to its own kind. They exhibit no capacities suscep- 
 tible of being unfolded, . perfected, or changed by 
 bringing their ideas into a common stock. In short, 
 the instinct of animals seems to want the essential 
 principle of voluntary improvement^ and, therefore, 
 of accauntability. To man is assigned the high and 
 noble prerogative of an intelligence susceptible of an 
 unbounded progress ; intrusted to his own cultivation; 
 capable of advancing the welfare of his species ; and 
 therefore laying the foundation of his moral and reli- 
 gious obligations to that Being who has exalted him 
 to a rank so glorious. 
 
 T. You have now attended to some of the prin- 
 cipal instances of Creative wisdom and goodness in 
 the animal frame. I presume you have noticed the 
 remark of Dr. Paley, that, in his opinion, " a designed 
 and studied mechanism is, in general, more evident 
 in animals than in plants ; and that it is unnecessary 
 to dwell upon a weaker argument, when a stronger is 
 at hand." It is true, plants are of a more simple 
 structure than animals ; and there is certainly no oc- 
 casion to strengthen the proofs of a Divine and benevo- 
 lent Providence you have already related. But not to 
 overlook a department of nature so familiar and beau- 
 tiful as the vegetable kingdom, you may mention 
 what you remember as to the uses and designs we 
 discover in plants. 
 ^2 
 
186 
 
 PLANTS. 
 
 PLANTS. 
 
 A. Plants the most valuable for food are the mos t 
 abundant and easily procured. It is an evident de- 
 sign also of a kind Providence, that plants are so 
 variousj as to be adapted to all changes and vicissi- 
 tudes of weather and climate — the seasons which are 
 less favorable to some are propitious to others. Di- 
 versities of soil — of hill and valley — are so many 
 different advantages for different vegetables, and for 
 the same vegetable. 
 
 It agrees with the same view of the subject to re- 
 mark that fruits are not, (which they might have 
 been), ready altogether, but that they ripen in succes- 
 sion throughout a great part of the year ; some in 
 summer ; some in autumn ; and that some require 
 the slow maturation of the winter, and supply the 
 spring. The most hardy of all plants is the grass. 
 It will bear to be trodden by the animals which have 
 to walk over the fields on which they graze. Of all 
 productions of the earth this is the most universal • 
 happily for the numerous tribes whose indispensable 
 food it is, and which could neither transport it them- 
 selvts, nor for which, valuable as they are to man? 
 could he afford to procure so bulky an article from 
 any considerable distance. 
 
 The warmer latitudes abound in fruits adapted to 
 allay thirst and mitigate heat ; such as the lime, the 
 lemon, the orange, the melon, and all acid and 
 
NATURAL THEOLOGY. 187 
 
 watery vegetables, in peculiar variety and perfection. 
 Those plants and fruits particularly suited to prevent 
 jputridity, which is one of the greatest dangers of 
 hot climates, are remarkably [abundant in such cli- 
 mates. These are the spices, the pepper, clove, 
 &c. and other aromatic vegetables which are obtain- 
 ed from the warm countries. 
 
 ^' One cannot open a volume of travels, but some 
 shrub or plant is made known to us, peculiarly adapt- 
 ed to the clime. In the Brazils a cane is found, 
 which on being cut below a joint, dispenses a cool, 
 pleasant liquid, which instantly quenches the most 
 burning thirst ; and Prince Maximilian, when travel- 
 ing in America in 1816, quenched his thirst by drink- 
 ing the water found within the leaves of the bro- 
 melia." 
 
 Mr. Elphinstone says, the water melon, the most 
 juicy of fruits, is found in profusion amid the arid 
 deserts of western Africa ; and adds, *' that it is really 
 a subject of wonder to see a melon, three or four 
 feet in circumference, growing from a stalk, as slen- 
 der as that of a common melon, in the dry sand of 
 the desert." 
 
 Mr. Barrow thus describes the curious vegetable, 
 fhe pitcher plant, " To the foot stalk of each leaf 
 ^s attached a bag, girt round with a lid. Contrary to 
 the usual effect, this lid opens in wet and dewy hours, 
 and, when the pitcher is full, the lid closes ; when 
 this store of moisture is absorbed by the plant, the 
 lid opens again," — (Thoughts on Domestic Educa- 
 tion.) 
 
188 PLANTS. 
 
 " The food afforded by the soil in each climate," 
 says a late philosophical author, '' is admirably adapt- 
 ed to the maintenance of the organic constitution in 
 health, and to the supply of the muscular energy 
 requisite for the particular wants of the situation. 
 In the Arctic Regions no farinaceous Jood ripens ; 
 but on putting the question to Dr. Richardson, how 
 he accustomed to the bread and vegetables of the 
 teraperarate regions, was able to endure the pure 
 animal diet, which formed his only support on his ex- 
 pedition to the shores of the Polar Sea, along with 
 Capt. Franklin, he replied, that the effects of the 
 extreme dry cold to which they were exposed, living, 
 as they did, constantly in the open air, was to pro- 
 duce a desire for the most stimulating food, they 
 could obtain ; that bread in such a climate was not 
 only 710^ desired, but comparatively impotent as an 
 article of diet ; that pure animal food, and the fatter 
 the better, was the only sustenance that maintained the 
 tone of the corporeal system, but that when it was 
 abundant, (and the quantity required was much grea- 
 ter than in milder latitudes), delightful vigor and 
 buoyancy of mind and body were enjoyed, that ren- 
 dered life highly agreeable.'' Here, therefore, we 
 see an admirable adaptation of the food to the cli- 
 mate ; — ^that while vegetable productions are few in 
 these cold regions, the oily animal substances are 
 remarkably abundan. 
 
 T. Do we discover any remarkable appearance 
 of design in the structure of plants ? 
 
NATURAL THEOLOGY. 189 
 
 A. Every plant furnishes occasion for admiring the 
 wisdom of the Creator. The seed and the fruit are the 
 most important parts. The seed is wanted to repro- 
 duce the plant ; and it is generally for the fruit the 
 plant is useful. We are first to observe the particu- 
 lar provisions which are made for both the seed and 
 the fruit in the structure of the plant. 
 
 T. This is an interesting portion of the subject, 
 and you may be a little particular ; first, as to the 
 parts which produce the fruit, 
 
 A, They are called by botanists the pointals and 
 stamens. They are the small fine threads we gener- 
 ally see inside the flower. The pointal is commonly 
 situated in the middle, terminating in a knob at the 
 top, which is called the stigma, and, in another at the 
 bottom, which is termed the germ, and which is to 
 become the fruit, and contain the seed. The stamens 
 usually surround the pointal in a circle ; bearing on 
 their upper extremities what are called the anthers, 
 which produce a dust, that is named the farina or 
 pollen. It is that yellow powder which comes off 
 upon the finger in a full blown flower. Its use is to 
 lodge upon the pointal, where it produces a certain 
 effect, which is found to be necessary for the forma- 
 tion of the fruit. Remove this dust and the plant 
 will produce nothing. 
 
 Whatever the form and situation of these curious 
 parts of the plant, without which it would be barren, 
 we discover an extraordinary degree of care exhibit- 
 ed by nature, to preserve them. First, they are 
 not exposed, till it is necessary, or till their office is 
 
190 PLANTS. 
 
 wanted, which is only when the plant is reaching its 
 full growth, and then they perform their duty in 
 a very short time. Till this period, they are careful- 
 ly and curiously wrapt up and protected, as we see in 
 the bud of a rose or the sheathe of a corn plant. 
 
 The huds of some trees, such as the balm of Gilead 
 and the horse chestnut, are uncommonly large during 
 the winter, and are then covered over with a resinous 
 or gurhmy substance. We behold Creative design 
 and wisdom in this arrai^gement. In all these trees, 
 the pointals and stamens are very considerably advan- 
 ced when the winter overtakes them. The unusual 
 size of the buds is adapted to this circumstance. 
 *^ They are wrapped up in these buds with a con^- 
 pactness which no art can imitate. This is not all. 
 The bud itself is inclosed in scales — which scales are 
 formed from the remains of past leaves and the rudi- 
 ments of future ones. Neither is this the whole. 
 In the coldest climates, a third provision is added by 
 the bud having a coat of gum or rosin, which being 
 congealed, resists the strongest frost. On the ap- 
 proach of warm weather, the gum is softened, and 
 ceases to be a hindrance to the leaves and flowers. 
 All this care is a part of that system of provisions 
 which has for its object the consummation and per- 
 fection of the seeds. 
 
 The poppy, while it is grgwing, hangs down its 
 head, and in this position it is impenetrable by rain. 
 When the head has acquired its size, and is ready to 
 open, the stalk erects itself for the purpose, it should 
 seem, of presenting the flower, and with the flow- 
 
NATURAL THEOLOGY. 191 
 
 er, the seed and fruit parts to the genial Influence 
 of the sun's rays. '^ This always struck me," adds 
 Dr. Paley, " as a curious property, and specifically 
 as well as originally provided for in the constitution of 
 the plant ; for if the stemhe only henthy the weight 
 of the head, how comes it to straighten itself, when 
 the head is is the heaviest ? These instances shew 
 the attention of nature, he observes, to the prin- 
 cipal object, the safety and maturation of the parts 
 upon which the seed depends. 
 
 Some plants, as the pea, the clover, &;c. have 
 a vane belonging to the flower, which the w^ind turns 
 in such a manner, as always to keep the more delicate 
 parts from facing the blast, like the contrivance we often 
 see on the tops of chimnies, to prevent the wind 
 from blowing upon the passage where the smoke is 
 discharged. The flowers of some plants, as the dande- 
 lion and many others, always shut up at night ; others, 
 like the English sunflower, have the singular property 
 of turning round, so as to follow the sun, and afibrd 
 the seed and fruit parts the constant advantage of 
 his rays. 
 
 T. Is there any thing in the cup or leaf part of 
 the flower which evinces design ? 
 
 A. It affords the advantage of a wall or a shelter 
 around the dehcate fruit parts within. Its shajpe is 
 generally well adapted to reflect the rays of the sun 
 toward the middle, where these parts are situated ; 
 and the high polish on the inside, must contribute to 
 the same efiect. It is observable, that it decays and 
 falls off, and is the only part of the plant that does, as 
 
192 PLANTS. 
 
 soon as the styles and stamens have performed their 
 office, and the delicate embryo of the fruit has 
 made a little progress in its growth. 
 
 T. Is there any thing to oblige the pollen or 
 dust, which is necessary for the formation of the 
 fruit, to light upon the pointal where its office is to 
 be performed ? 
 
 A. The provision for this purpose is remarkable. 
 In the first place, the pointal is generally in the mid- 
 dle, the most favorable situation for receiving the 
 dust from the stamens which stand around it. Sec- 
 ondly, it is usually shorter than the stamens, so that 
 the pollen more readily falls upon it. Sometimes the 
 head of the flower hangs down, as in the Crown Im- 
 perial. In this flower, therefore, the pointal ought to 
 be the longest, for the dust to catch upon it in its 
 descent from the stamens. We find upon examina- 
 tion, the usual relative length of the pointal is here 
 actually inverted, and is greater than that of the sta- 
 mens. It is generally the same in all the drooping 
 flowers. 
 
 In some flowers the stamens lean over, one or two 
 at a time, on the pointal, retiring after they have shed 
 their dust and giving place to others. This is very 
 striking in the Garden Rue. The five stamens of 
 the Cockscomb, ( Celosia) are connected at their 
 lower part by a membranous web which in moist 
 weather is relaxed, and the stamens spread for shel- 
 ter under the leaves of the flower ; but, when the air 
 is dry, the contraction of the membrane brings them 
 together, to scatter their pollen in the centre of the 
 
NATURAL THEOLOGY. 193 
 
 flower. There is a similar fact with respect to the 
 beautiful shrub which many call the sheep kill or 
 lamb Icill ; botanists, the Jcalmia. The ends of the 
 stamens are bent back and protected in little depres- 
 sions upon the inside of the cup of the flower, until, at 
 the proper time, they suddenly liberate themselves 
 from their confinement, and dash the pollen with 
 great force upon the pointal. In the barberry hush, 
 {Berberis), the stamens shelter themselves under 
 the leaves of the flowers, whose tips bend over a lit- 
 tle to receive them, till some little insect in search of 
 honey, happens to touch them at the bottom, when they 
 dart forward, like a sprung trap, and discharge their 
 dust upon the pointal in the same way, — and this 
 operation may be repeated in the same flower. Dif- 
 ferent species of flowers float entirely under water, 
 often at some considerable depth, when they rise near 
 the surface, and throw up their flower spikes above 
 it, and sinking afterwards to ripen and sow their seeds 
 at the bottom. ^ 
 
 There are some plants in which the pollen could 
 not easily perform its office, if it were not for a spe- 
 cial provision. In the Indian corn the pointals, (or 
 silk,) are quite remote from the stamens (or the bran- 
 ches of the spindles) ; and not only so, the broad 
 leaves of the pi ant would be likely to intercept the 
 dust and prevent it from falling in the right p lace : 
 in some trees and vegetables the pointals are upon 
 one, and the stamens upon another, as in the pine, 
 nut, mulberry, he. There is a provision against 
 
194 PLANTS. 
 
 this difficulty ; and it forms one of the most curious 
 facts in botany. The pollen is light and floats off 
 easily into the air so as to escape obstructions or 
 pass from plant to plant. It is done in this man- 
 ner. Every particle of the pollen contains a very 
 minute quantity of what the chemist terms hy- 
 drogen gas, which is much lighter than air, and 
 which, for that reason, is used in inflating balloons. 
 Now to steer these little particles to their destin- 
 ed places there is said to be an attraction between 
 the dust and the part for which it is designed ; and 
 that as soon as it lodges upon this part, the balloon 
 bursts, the hydrogen escapes, and the dust remains 
 fixed upon the pointal where there is a gummy 
 substance to hold it fast. 
 
 B. Another beautiful instance in which our most 
 ingenious arts have a more perfect precedent and 
 'pattern in the works of Creation ! Here, it seems, 
 we not only have the balloon, but what our aero- 
 nauts have yet to discover, how to direct its 
 course. 
 
 A. In the seeds of plants, we have to notice the 
 gre at principle we see in all the works of nature, that 
 every thing is provided far with an attention propor- 
 tionate to its importance. If the seed should fail, 
 the plant cannot be reproduced. We may here 
 therefore admire, that this part of every vegetable 
 discovers the most care for its perfection and preser- 
 vation. We find it in shells, stones, husks, pods ; 
 always cased and defended by something hard, so 
 that however rudely we may handle it, the miniature 
 
NATURAL THEOLOGY. 195 
 
 plant within remains unhurt. As if endowed with 
 a knowledge of the tender embryo it contains, the 
 seed will never expose it by opening in any situation 
 where the little root would want warmth and mois- 
 ture to nourish it. 
 
 We have this exemplified in the backwarclness of 
 seeds in a dry, cold spring. The seed, as we may 
 -eay, is here often wiser than the planter ; who 
 regrets the tardiness of the germination, without 
 reflecting that any precipitancy in this particular 
 would be fatal to the plant. It is an admirable 
 constitution of seeds which we can only refer to de- 
 sign, that they are invariably slow in opening when 
 the safety of the plant requires they should not 
 begin to shoot shortly after they naturally fall; as 
 is the case with nuts and many othciv^, which are 
 dropped too late for the plant to become suffi- 
 ciently hardy to endure the cold of winter. 
 
 From one part of the seed, the sprout comes forth 
 which is to form the stem ; and from another the 
 sprouts which are to become the roots. This provi- 
 sion is a curiosity of vegetable instinct ; though some 
 have thought the attraction of the earth, or gravita- 
 tion has much to do with it. But it is to be admi- 
 red, however accounted for. For deposit the seed in 
 the ground in any manner we may, the stem comes 
 up, the root goes down. This buisness is not left 
 to our care ; that is to say, what we could not easily 
 do if we would, plant every seed in a particular 
 position, is rendered unnecessary by the wise provi- 
 sion of the Creator. 
 
196 
 
 PLANTS. 
 
 The same providence attends the plant in the 
 different stages of its growth. The provisions for 
 supporting the plant, and giving it the benefit of sun 
 and rain are a manifest display of purpose and 
 wisdorti. The stems are made strong and erect for 
 this purpose, with one large class of exceptions, such 
 as the honey-suckle, grape vine, &c. These are fur- 
 nished with a substitute viz. the tendrils, by which 
 they are enabled to climb up. One might be chal- 
 lenged to imagine a clearer instance of design than 
 this ; thus there is not one tree or shrub or herb 
 which is able to stand alone, that is furnished with 
 a tendril. " We may make only so simple a com- 
 parison as that between a pea and a bean. Why 
 does the pea put forth tendrils, the bean not ; but be- 
 cause the stalk of the pea cannot support itself w^ith- 
 out them, the stalk of the bean can ; we may add 
 also a circumstance not to be overlooked, that, in 
 the pea tribe these clasps to do not make their ap- 
 pearance till they are wanted ; till the plant has 
 grown to a height to stand in need of support. " 
 
 Plants are generally more or less improved from 
 their natural state, by cultivation. Some acquire new 
 fragrance and beauty. In others, the fruit is render- 
 ed more wholesome, delicious and abundant. The 
 rose, by being transplanted from its native fields, has 
 been changed from a single flower into one of the 
 most magnificent ornaments of our gardens. The 
 apple, pear, &c. on the contrary, have been improv- 
 ed principally in the fruit. In this singular differ- 
 ence in the effects of cultivation in different plants, 
 
NATURAL THEOLOGY. 
 
 197 
 
 for which there is no natural reason we know of, we 
 can plainly see the goodness of Providence. The 
 case is this : the improvement produced by cultivation 
 in the beauty of flowers, chiefly consists in increas- 
 ing the number of the flower leaves, botanists term 
 them the petals, which in those flowers, called 
 double flowers occupy the cup designed for the fruit 
 bearing parts, that is, the pointal and stamens, so that 
 the improved beauty is not obtained but at the ex- 
 pense of the fruit and the seed. The design intended 
 to be noticed is this ; that when it is the jlo^jer 
 which is changed, we shall find the general distinc- 
 tion is, that it takes place in those plants whose prin- 
 cipal value to us is their beauty ; while fruit trees 
 preserve the simplicity of the flower ; and the im- 
 provement is confined to the fruit under every degree 
 of culture. It would be a small compensation for 
 the barrenness of our orchards, that the flowers were 
 double in the spring. Why in the rose bush, cul- 
 tivation doubles the flower, and the apple, (the red 
 bud), is not improved; and in the orchard trees, it 
 improves the apple, and leaves the flower single, can 
 only be attributed to that beneficent design, which 
 in every thing has consulted the greatest degree of 
 utility. The original potatoe was introduced into 
 Europe from the mountains of Peru, and has become 
 infinitely more valuable, as an article of food, by cul- 
 tivation. Here the root is improved ; but the flower 
 remains as simple as in the state of nature. A more 
 beautiful potatoe field would poorly reward us for the 
 b2 
 
198 
 
 PLANTS. 
 
 loss of one the most valuable vegetables. The same 
 is true cf the esculent roots, the carrot, parsnip, and 
 many others. 
 
 B. How striking an evidence of benevolent de- 
 sign 1 Every plant is made to improve for the bene- 
 fit of the cultivator ; and laws apparently the most 
 arbitrary are estabhshed, by vdiich the Armc/ of im- 
 provement is such as would be most for our advant- 
 age. 
 
 T. What are the properties of plants in which we 
 discover a wise and benevolent Providence ? 
 
 A. Besides nutritive, medicinal, and ornamental 
 plants, which contribute to our benefit and enjoyment 
 in innumerable ways, all plants exert a salubrious in- 
 fluence on the air. The air is found to undergo a 
 chemical change by every breath we inhale, every 
 fire we kindle, which unfits it for respiration. It loses 
 a certain principle necessary to support animal life. 
 At the same time its purity is impaired by the con- 
 tinued decay of animal and vegetable substances. — 
 Amid all these causes which operate to diminish the 
 purity of the air, nature has provided the plant as a 
 rjstorative. It restores the salubrious quality which 
 has been removed ; \\, removes the pestilential quality 
 which has been imparted. 
 
 B. One would suppose that all these had proper- 
 ties could not be removed by the plant, without its 
 suffering for the friendly office which it performs. 
 
 A. The plant derives nourishment from the air 
 which has been contaminated by the animal ; while it 
 
NATURAL THEOLOGY. 199 
 
 exhales in return the vital principle which the animal 
 wants. 
 
 T. Such used to be the theory. But late expe- 
 riments have given rise to some different views upon 
 this subject. 
 
 A. Agitation ivith ivater is one of the restoring 
 causes which the wisdom of the Creator has provided 
 to purify the air. *' The foulest air shaken in a bot- 
 tle with water for a sufficient length of time, recovers 
 a great degree of its purity. Here we see the salu- 
 tary effects of storm and tempests. The yesty waves, 
 which confound the heaven and the sea, are doing 
 the very thing which is done in the bottle. Nothing 
 can be of greater importance to the living creation, 
 than the salubrity of the atmosphere. It ought to 
 reconcile us therefore to these agitations of the ele- 
 ments, of which we are apt to deplore the conse- 
 quences, to know, that they tend powerfully to restore 
 to the air that purity which many causes are continu- 
 ally impairing. 
 
 B. Hence I suppose that delightful sweetness and 
 freshness of the air after a shower. 
 
 T. What are some other of the principal marks 
 of design we discover in the elements ? 
 
 A. Without air, neither vegetable nor animal life 
 could be supported. Water could not be carried up 
 from the earth, nor supported in the form of clouds, 
 nor when descending, could be distributed in dew 
 and rain drops. Without the air to reflect the rays 
 of light, the instant we turned our back upon the sun, 
 we should be immersed in total darkness. 
 
200 PLANTS. 
 
 In water, it demands our gratitude, that the most 
 necessary liquid is the most abundant and most easily- 
 obtained, and has no taste of its own either to offend, 
 or satiate ; or to effect the flavor of any thing uni- 
 ted with it. One of most remarkable circumstances 
 in which we discover design in the properties of wa- 
 ter, is the manner in which it is affected hy frost. It 
 is a provision in the constitution of this most useful 
 element, to preserve it from the sudden effects of hard 
 frosts ; that is, in those places where it is of the 
 greatest importance to us, viz. the deeper waters, 
 such as wells, rivers, bays, &ic. A short account of 
 the matter may be this. Water will not freeze, till it 
 is cooled down to thirty-two degrees of the common 
 thermometer. But water is heavist when at the 
 temperature of about forty degrees. The conse- 
 quence is plain. When the surface of the water is 
 cooled by a cold wind or a sharp air, to the temper- 
 ature of forty degrees, it does not wait to be cooled 
 down to the freezing point, which is eight deegrees 
 lower, and to which it would sooa be brought if it 
 remained above, exposed to the cold ; but being the 
 heaviest, it immediately sinJcs, and suffers a warmer 
 portion below to take its place This, also, when 
 reduced to the same temperature of 40, repeats the 
 process ; and thus the whole quantity must come to 
 the surface and be brought to this particular degree 
 of cold, which is eight degrees above the freezing 
 point, before the circulation will stop. After the 
 whole mass has thus been brought to the heaviest 
 weight w^hich water can acquire, then the surface 
 
NATURAL THEOLOGY. 201 
 
 will remain stationary, and the cold wind or air will 
 soon reduce it to the state of ice. The time necessary 
 for this circulation to be completed, must depend on 
 the depth of the water ; and in deep pieces of water, 
 it is sufficiently long to ensure them from being fro- 
 zen over, unless the cold should be continued for 
 a considerable period. 
 
 To this provision we are indebted for the use of 
 our wells, fountains, and navigable waters in cold 
 weather. They would otherwise be closed up with 
 the first frosty night. The whole fact is one of 
 modern discovery, Dr. Johnson was led to doubt that 
 a small but very deep lake in the highlands of Scot- 
 land, was always open in the hardest winters, while 
 other lakes in the neighborhood were frozen over. 
 If the fact were true, he thought the phenomenon 
 must be owing to the water being unusually sheltered. 
 
 " For where a wide surface," he observes, " is 
 exposed to the full influence of a freezing atmos- 
 phere, I know not why the depth should keep it 
 open. " The difficulty to his mind of conceiving 
 how depth should protect the surface, may still fur- 
 ther impress us with the wisdom of the arrangement 
 by which the effect is produced. 
 
 Without fire, all substances would be converted 
 into one solid mass ; fire being the principle of fluid- 
 ity in water and every other liquid in nature. The 
 very air itself would become solid. Fire is the 
 universal instrument of all the arts and all the neces- 
 saries of life ; and here we are called to admire, that 
 fire and light, in the absence of the sun, are obtain- 
 
202 ASTRONOMY. 
 
 able, and so easily, from a variety of sources, such as 
 wood, oil, and all combustible bodies : — and what is 
 more observable, since we could not have conceived 
 of its possibilty, this diffusive and destructive ele- 
 ment of fire is so quietly and safely concealed in all 
 these substances, till we have occasion to rpake use 
 of it. 
 
 ASTRONOMY. 
 
 T. It becomes most interesting to inquire whether 
 we are able to pursue the same system of design into 
 the remoter parts of the universe which fall within 
 our observation. 
 
 A. We are not indeed able to pursue our re- 
 searches into the heavenly bodies, as into the struc- 
 ture of a plant or animal ; but the knowledge we have 
 is sufficient to convince us they are a continuation of 
 the same skilful and beneficent contrivance we find to 
 be so perfect in the objects we are able to examine; 
 that is, to examine so nearly as to trace the minute 
 relations and correspondency of parts. 
 
 T. You may mention some of the most conspicu- 
 ous marks of design and wisdom in the Solar System. 
 
 A. In the first place, it is a plain manifestation of 
 design and of a designing Creator, that the Sun is situ- 
 ated in the centre ; and that the earth and planets 
 are disposed around the orb by which they are warm- 
 
NATUBAL THEOLOGY. 203 
 
 ed and enlightened ; that is to say, that the bodies 
 which require the benefit of his illumination and heat, 
 are placed in the most favorable position for receiving 
 them. We know of no natural cause why the central 
 body must be luminous. We see the wisdom of the 
 arrangement ; but here our knowledge ends. 
 
 T. But there is more to excite an admiration of 
 the wisdom exhibited in this stupendous part of the 
 fabric of the universe. 
 
 A. In the revolution of the earth and planets 
 around the sun we behold an example of mechanism 
 on a scale exceeding our imagination ; but still, where- 
 in we perceive manifest contrivance ; as much as in 
 the motion of a watch or the turning of a joint. — 
 The planets revolve by means of two forces. The 
 one is the force of attraction which the sun exerts 
 upon them, like that of steel upon a magnet. It is 
 termed the force oi gravitation : and if they were to 
 comply with this force only, they would rush to the 
 sun and be consumed. The other force is one which 
 continually impels them to move off from the sun, 
 like a ball from a sling ; and if they had obeyed this 
 force alone, they would long since have withdrawn 
 from their orbits into the depths of infinite space. — 
 The whole is perfectly illustrated by the whirling 
 round of a ball fastened to the end of a string. The 
 ball is drawn to the hand by the string ; this is one 
 force ; the motion of the ball impels it to recede from 
 the hand, so that if the string should separate, the 
 ball would fly away. This is the other force. Both 
 acting together, compel the ball to revolve round the 
 
304 
 
 ASTRONOMY. 
 
 hand. In the planetary revolutions there are the 
 same two forces ; the only difference being, that the 
 attraction of the sun upon the planets is a substitute 
 for the string. 
 
 B. From how simple powers are the most stupen- 
 dous effects produced in nature ! What an amazing 
 conception, that the simplest toy of a child compre- 
 hends the whole mechanism of worlds all in rapid 
 motion, yet calm, regular and harmonious. 
 
 T. But this admirable mechanism is not to be un- 
 derstood from so simple an illustration as this, except 
 in some very general points of view. There are im- 
 portant respects in which it fails to convey any ade- 
 quate idea of the wisdom exhibited in the planetary 
 frame. The earth and planets are held in their orbits 
 by the attraction of the Sun. This is true. But the 
 attraction- is not peculiar to the Sun. It is an attrac- 
 tion which all bodies exert upon one another in pro- 
 portion to their quantities of matter. The sun being 
 by far the largest body in the system, possesses the most 
 of this attractive power, on account of his superior 
 magnitude. And all the planets exert the same kind 
 of attraction upon one another, though in a less de- 
 gree. If we were to fasten a number of loadstones 
 to separate strings, and whirl them around another 
 larger loadstone in our hand, this would resemble the 
 sun and planets ; — but then while the loadstones re- 
 volved they would be liable, from their natural attrac- 
 tion, to rush together and form one solid mass. What 
 is to prevent the planets from doing the same, and 
 involving the whole system in destruction ? 
 
NATURAL THEOLOGY. 2(fe 
 
 A. We have here new occasion to acknowledge 
 the Creator's wisdom in preserving the harmony of 
 the system by one of the most wonderful laws which 
 he has impressed upon matter. It is this. While 
 the earth and all planets are continually exerting an 
 amazing force of attraction upon one another, like so 
 many loadstones, yet the mathematician can demon- 
 strate they shall never rush together, nor materially 
 disturb their respective revolutions, provided a few 
 conditions exist. One condition necessary is, that 
 the attraction be weaker the farther they are apart ; 
 and not only so, — but exactly four times weaker, 
 when the distance is doubled. Upon this condition 
 and a few others, but this is the principal, he is able 
 to demonstrate, without observing the heavens, with- 
 out seeing how the fact in reality is, there, — that no 
 danger exists from the mutual attraction of the heav- 
 enly bodies ; draw upon one another as long and as 
 powerfully as they are able ; change their relative 
 positions as they can ; now retreating, now advan- 
 cing; here the matter must end; they can never 
 touch, they can never permanently disturb each oth- 
 er's separate and orderly revolutions. Now, wonderful 
 as it must seem, all these conditions exist in the solar 
 system ; and among others the main and most impor- 
 tant one, to wit, the force of planetary attraction is 
 exactly four times weaker at twice the distance. 
 
 Why not three times, or five times, or in any other 
 proportion ? Of the infinite number of possible pro- 
 portions, had it been any other than the one actually 
 s 
 
^06 CONCLUSION. 
 
 adopted, it has been demonstrated, so far as the in- 
 vestigation has been carried, that the consequences 
 would have been fatal. But still, what has established 
 this particular law of the attractive power? As an 
 eminent mathematician observed, we know of no rea- 
 son, but that it was so established. 
 
 T. It is sufficient for our present views to notice 
 a few only of the connected instances of design we 
 perceive in nature, and which stamp one united im- 
 press of the Supreme Creator upon every object; to 
 see every thing concurring in the same demonstration 
 of his Almighty agency ; and announcing the Eternal 
 Power of whose perfections we have been privileged 
 with such glorious manifestations. I shall not pursue 
 the consideration of all the particular attributes of the 
 Deity which are evidenced ; such as his Unity, Eter- 
 nity, Immensity, Omnipotence, and Infinite Wisdom ; 
 but will now ask what is the grand conclusion we ob- 
 tain from a collected view of those innumerable traces 
 of design we discover in the works of God. To what 
 end does design appear to be directed ? 
 
 A. A good and benevolent end. In countless in- 
 stances we are enabled immediately to perceive this 
 end ; and the presumption is overwhelming, that it is 
 universal, and that all creation is a display of the infi- 
 nite goodness of its gracious and adorable Author. 
 
 Whatever we observe in nature, which lies within a 
 compass so suited to our knowledge, that is, so limited 
 a compass, that we can feel satisfied that we un- 
 derstand it ; that we see the end to be obtained, and 
 the means suitable to be employed ; in every such in- 
 
NATURAL THEOLOGY. 207 
 
 Stance, we discover a useful and beneficent arrange- 
 ment actually adopted, and no other. In examining 
 the human frame ; the mechanism of the bones and 
 muscles ; the organs for nourishing the system ; the 
 admirable covering by vi^hich it is shielded, and pre- 
 served in an agreeable and healthy temperature ; — 
 here is a case within our comprehension. We see 
 the objects to be effected ; and we understand in a 
 good degree, the means which are necessary to effect 
 them. We see that a locomotive animal, an animal 
 that must move in order to subsist, requires limbs of 
 particular dimensions and forms ; — and muscles adapt- 
 ed to set these limbs in motion ; and alimentary ap- 
 paratus to support these muscles in life and vigor. It 
 is a case within our comprehension : only a few plain 
 principles of contrivance happen here to be involved, 
 similar, for the most part, to those we are familiar 
 with in mechanism of our own ; and here we discover 
 the most consummate evidence of design usefully and 
 benevolently directed. We are acquainted with the 
 mechanical powers. We understand the nature of a 
 pulley. We Jcnow what is to be done, if it is proper 
 the eye should be drawn upward or downward, or in 
 this direction or in that, for the purposes of vision. 
 We find it is done. If the human body is to be 
 nourished by food, which food must be divided and 
 ground to fit it for the digestive organs ; here is a 
 case within our certain comprehension, in the end and 
 in the means ; and we can unhesitatingly pronounce, 
 that teeth are a necessary provision. We find them 
 provided ; and in every animal perfectly adapted to 
 
208 ' CONCLUSION. 
 
 the nature of the animars food. Here is a fitness of 
 which we are competent to judge, because it happens 
 to be too simple, — involves too few principles, for us 
 to mistake. 
 
 When the nature of the case brings it fully within 
 our knowledge, the arrangements we discover are in- 
 variably perfect. And when we consider how nume- 
 rous, how countless are the instances of this descrip- 
 tion, through all the multitude of living and organized 
 beings ; through all the complexity of their structure ; 
 through all the adaptations of their powers, physical 
 and instinctive, to their subsistence and comfort ; 
 through so many cases of wise and benevolent ar- 
 rangement in the vast compass of nature ; we cannot 
 reflect without the profoundest admiration, that in 
 proportion as our knowledge of any thing in creation 
 approaches to certainty, our perceptions of Divine 
 wisdom and benevolence are satisfactory and uncloud- 
 ed. What an argument for suffering no limitation of 
 our trust and adoration towards that High and Holy 
 One, of whom, and through whom, and to whom are 
 all things I What a reason for bowing with devout 
 and cheerful acquiescence to the precept of our Sav- 
 iour, who suggested the same idea in commanding his 
 disciples, as to all future events, and all things occa- 
 sioning tjieir solicitude, to confide in that Being who 
 had so perfectly exhibited his goodness in cases with- 
 in their certain knowledge and actual observation ! 
 Behold the fowls of the air : for they sow not, nei- 
 ther do they reap, nor gather into barns ; yet your 
 
NATURAL THEOLOGY. 209 
 
 heavenly Father feedeth them. Are ye not much 
 better than they. 
 
 To say, that in all the innumerable contrivances of 
 nature there are prevalent marks of a merciful and be- 
 nevolent author, is to pronounce that all his intentions 
 are gracious ; as what is prevalent in his acts, must 
 determine the nature of his intentions, and be regarded 
 as the decisive indication of his moral character. Tlie 
 general impress, therefore, of beneficent design, so 
 legibly stamped upon the operations of Providence, is 
 of itself sufficient to demonstrate, that the goodness of 
 Omnipotence is every where exhibited, and that all 
 its designs are good. " Nor, (as it has been truly 
 said by a most devout and delightful writer), is the 
 design abortive. The air, the earth, the water, teem 
 with delighted existence. In a spring morn, or a sum- 
 mer evening, on whichever side I turn my eye, my- 
 riads of happy beings crowd upon my view. The in- 
 sect youth are on the wing. Swarms of new born 
 flies are trying their pinions in the air. Their spor- 
 tive motions, their wanton mazes, their gratuitous ac- 
 tivity, their continual change of place without use or 
 purpose, testify their joy, and the exultation they feel 
 in their lately discovered faculties. At this moment, 
 in every given moment of time, how many myriads of 
 animals are eating their food, gratifying their appe- 
 tites, ruminating in their holes, accomplishing their 
 wishes, pursuing their pleasures, taking their pastimes. 
 In each individual, how many things must go right, 
 for it to be at ease ; yet how large a proportion out 
 s2 
 
210 CONCLUSION. 
 
 of every species is so in every assignable instant. 
 In our own species, the preponderance of good over 
 evil, of health, for example, and ease, over pain and 
 distress, is evinced by the very notice which calami- 
 ties excite. What inquiries does the sickness of our 
 friends produce ? What conversation their misfortunes ? 
 This shows that the common course of things is in fa- 
 vor of happiness ; that happiness is the rule — misery 
 the exception. Were the order reversed, our atten- 
 tion w^ould.be called to examples of health and com- 
 petency, instead of disease and want. One great 
 cause of our insensibility to the goodness of the Crea- 
 tor is the very extensiveness of his bounty." 
 
 T. Do we discover any arrangement of Provi- 
 dence that seems intended for the production of mere 
 pain or unhappiness ? 
 
 A. No one, it is believed, will profess to be ac- 
 quainted with such an instance. Evil, as such, never 
 appears an end in any thing in nature, with which we 
 are acquainted. In describing a particular tool you 
 would hardly say, this is made to cut the mechanic's 
 hand ; though from inattention in the use of it, this 
 mischief may often occur. " But if one had occasion 
 to describe instruments of torture, he would say, this 
 engine is to extend the sinews ; this to dislocate the 
 joints; this to break the bones; this to scorch the 
 soles of the feet. Here pain and misery are the very 
 objects of contrivance. Now, nothing of this sort is 
 ever to be found in the works of nature. We never dis- 
 cover a train of contrivance to bring about an evil pur- 
 pose. No anatomist ever discovered a train of organi- 
 
NATURAL THEOLOGY. 211 
 
 zation calculated to produce pain and disease ; or in 
 explaining the parts of the human body, ever said, 
 this is to irritate ; this to inflame ; this gland is to se- 
 crete the humor which forms the gout." If he is ig- 
 norant of a useful purpose, he considers his knowledge 
 as yet imperfect ; and pursues his inquiries with the 
 fullest confidence that there is yet a discovery to be 
 made. 
 
 T. If there are so many demonstrations of benefi- 
 cent design in the works of Divine Providence, which 
 we are able to perceive and understand ; and there is 
 no instance where a want of design can be proved ; 
 and none in which evil, as such, appears to be the ob- 
 ject of design ; — what is the proper view to be taken 
 of any of the seeming ills of life which God has ap- 
 pointed to us ? 
 
 A. Revelation declares they are intended for a 
 wise and beneficial purpose ; and any other conclu- 
 sion would be infinitely unreasonable. It would be 
 infinitely unreasonable to suppose that any thing in 
 Providence should want a useful design even though 
 it be pain and affliction, when we see the evidence 
 there is of a wise and benevolent Being whose tender 
 mercies are over all his works. 
 
 T. But what say you to such evils as the vices 
 and sins of which men are guilty ? 
 
 A. These are not the evils of Providence ; but 
 they are those which men bring upon themselves 
 by their own misconduct, thwarting the designs of 
 their being, and the kind purposes of their nature. 
 
212 CONCLUSION. 
 
 T. Wherein do you perceive in nioral evils any 
 thivarting of a natural design ? 
 
 A. God has made inconvenience and suffering, of 
 some description or other, the regular and natural 
 consequence of all criminal and excessive indulgences 
 of our passions ; and this proves a natural design has 
 been violated, — as much, as the pain which arises 
 from bending a limb contrary to the natural direction 
 of the joint, evinces that the limb was not intended 
 to be bent in that manner. Besides, our Creator 
 has placed reason and conscience in our breasts, 
 which always oppose the commission of conscious 
 vice and misconduct : — and we feci that they are by 
 right the presiding governers of our behavior. We 
 are as naturally sensible of it as of any truth what- 
 ever. 
 
 T. But Providence has subjected the best to 
 suffer in this world ; and oftentimes it is their virtu- 
 ous feelings which occasion their troubles ; as when 
 they suffer under the reproaches and ill treatment of 
 bad men ; or from the strength of their virtuous at- 
 tachments to other sufferers. They are subjected 
 also to death ; and, what it is impossible to overlook or 
 conceal, the more they cultivate their minds, and follow 
 the impulse of those noble capacities with which God 
 has endowed them, the more unhappy do they feel 
 it, to be denied the opportunity of continued ad- 
 vancement in improvement and usefulness ; the more 
 they know of their Creator, the more they adore and 
 love him, the more terrible to think of being separa- 
 rated from him forever. What design can you dis- 
 
NATURAL THEOLOGY. 213 
 
 cover here ? — What design in such a constitution 
 as this ; that the tetter use we make of our minds, 
 the more does this life appear too short and inade- 
 quate to our feelings ? 
 
 A. The system of Providence would lead us to 
 conclude from what we generally see, that capacities 
 are not given in vain. They are not made systemat- 
 ically and as a settled course to stop before they . 
 have finished their work, and reached their highest 
 consummation. Generally, the animal being does 
 not perish till its powers are perfectly developed ; 
 nor the tree till it has reached its height. If there- 
 fore man has capacities of higher improvement than 
 the present world unfolds, the presumption on natural 
 principles is, that this life is to be succeeded by an- 
 other. We see the best of the creatures of God, 
 universally stopped in their career ; stopped by infir- 
 mity and death ; stopped in their progress ; stopped 
 at the period of their most pleasing and rapid prog- 
 ress. Not so with the brute. His powers have no 
 progress that we know of He has reached the end 
 of his faculties, to all appearance, long before he 
 dies. The plant has reached the termination of its 
 vegetative powers of bloom and of fruit bearing, be- 
 fore it decays. But man is stopped. The tree falls 
 in mid vigor. The sun goes down at noon. 
 
 T. But is there any natural example to corres- 
 pond to the delightful and glorious anticipation of 
 a renewed period of existence for those capacities of 
 improvement, which in this life are arrested in their 
 progress ? 
 
214 CONCLUSION. 
 
 A. The examples are often before us. — -The seed 
 has capacities of further advancement, that is, of 
 shooting up into a tree, when it apparently dies in 
 the earth ; and the consequence is, the death is only 
 apparent. The tree actually succeeds. The worm 
 has capacities of further advancement, of advancing 
 from the earth to the air ; and the consequence is, it 
 leaves its shroud, and soars upwards from a state of 
 seeming insensibility, to enjoy the more beautiful ex- 
 istence of a butterfly. Prior to experience, neither 
 of these events would have been anticipated. We 
 see a butterfly in a maggot no more distinctly than 
 we see an immortal spirit in mortal man. 
 
 T. But in so important a case might we not have 
 expected some further evidence ? 
 
 A. That evidence we enjoy in the Revelation 
 hy Jesus Christ, who has brought life and immortality 
 to light. 
 
 T. And what has Christ Jesus taught us respect- 
 ing a future life ? 
 
 A. That it shall be a state of recompense accord- 
 ing to our characters. He has told us that the pres- 
 ent life is a state intended to' prepare us by the 
 knowledge of God we here acquire, the holy dispo- 
 sitions here formed in our souls, and the practice of 
 piety and virtue, for a state of heavenly felicity ; and 
 that' if we love wickedness, neglect our minds, and 
 hearts, and abuse the talents which God has given us, 
 — the consequence will be misery hereafter. 
 
 T. Do you see any thing in the present course 
 of Divine Providence in this life, to correspond to this 
 
NATURAL THEOLOGY. 215 
 
 representation which Jesus Christ has given us of 
 a state of recompense ? 
 
 A. Yes. In the general providence of God child- 
 hood has very much the same relation to mature age, 
 as this world has to the world to come« If we fail 
 to govern our passions when we are young, they 
 usually govern us, and render us miserable in the after 
 stages of life. If we then form virtuous and religious 
 habits, cultivate our minds, and improve our opportu- 
 nities aright, we are sure to rewarded in the effect 
 produced upon our characters, feehngs, and happiness 
 in the future periods of our days. The good and 
 the evil are placed before the child; and as his 
 choice and conduct shall be, so, in the general course 
 of divine providence, are manhood and old age re- 
 munerated. — Not so, with any' other being but man. 
 It is not left with the chicken to choose whether or 
 not it will follow its instincts, so as to become 
 a happy bird, when it has grown up. In ouv present 
 existence, therefore, there is a distinction from that 
 of inferior animals, similar to what revelation teach- 
 es us to expect with reference to a. future state. 
 
 T. And now, what ought to be your endeavor 
 and your prayer ? 
 
 A. What I desire to ask is that mine may ever be, 
 " &y patient continuance in well doing to seeJc for 
 glory, honor and immortality. " 
 
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