« AnteriorContinuar »
drupeds the aliment is first broken preserving it till fit for use, or for cups and bruised by mechauical instru. and glasses for bringing it, when ments of mastication, viz. sharp wanted, to the lip of the consumer. spikes or hard knobs pressing against The character of the machinery is in or rubbing upon one another: thus both cases this, that one part answers ground and comminuted it is carried to another part, and boili to the final by a pipe into the stomach, where it result. waits to undergo a great chymical ac “This parallel between the alimention, which we call digestion; when tary operation, and some of the prodigested, it is delivered through an cesses of art, might be carried furtber oritice, which opens and shuts, as into detail. Spallanzani has rethere is occasion, into the first in marked a circumstantial resemblance testine : there, after being mixed between the stomachs of gallinaceous with proper ingredients, poured fowls and the structure of corn-mills. through a hole in the side of the Whilst the two sides of the gizzard vessel, it is further dissolved : in this perform the office of the mill-stones, state the milk, chyle, or part which ihe craw or crop supplies the place is wanted, and which is suited for of the hopper. When our fowls are animal nourishment, is strained off abundantly supplied with meat, they by the mouths of very small tubes soon fill their craw; but it does not opening into the cavity of the intes- immediately pass thence into the tínes : thus freed from its grosser gizzard ; it always enters in very parts, the percolated fluid is carried small quantities, in proportion to the by a long, winding, but traceable progress of trituration : in like mancourse, into the main stream of the ner as in a mill, a receiver is fixed old circulation, which conveys it, in above the two large stones which its progress, to every part of the body. Serve for grinding the corn, which Now I say again, compare this with receiver, although the corn be put the process of a manufactory; with into it by bushels
, allows the grain to the making of cyder, for example ; dribble only in small quantities into the bruising of apples in the mill
, the central hole in the upper millthe squeezing of them when so bruised in the press, the fermentation in the “ But we have not done with the vat, the bestowing of the liquor thus alimentary history. There subsists fermented in the hogsheads, the a general relation between the exterdrawing off into bottles, the pouring nal organs of an animal, by which it out for use into the glass. Let any procures its food, and the internal one shew me any difference between powers by which it digest it. Birds these two cases, as to the point of of prey by their talons and beaks contrivance. That which is at pre are qualited to seize and devour many sent under our consideration, the species, both of other birds, and of ' relatiou' of the parts successively quadrupeds. The constitution of the employed, is not more clear in the stomach agrees exactly with the form last case than in the first. The apt. of the members. The gastric juice of ness of the jaws and teeth to prepare a bird of prey, of an owl, a falcon, or the food for the stomach is at least a kite, acts upon the animal fibre as manifest as that of the cyder mill alone; will not act upon seeds or to crush the apples for the press. grasses at all. On the other hand, The concoction of the food in the the conformation of the mouth of stomach is as necessary for its future the sheep or the ox is suited for use, as the fermentation of the steem browsing upon berbage. Nothing in the vat is to the perfection of the about those animals is fitted for the liquor. The disposal of the aliment pursuit of living prey. Accordingly, afterwards; the action and changes it has been found by experiments, tried which it undergoes; the rout which not many years ago with perforated it is made to take in order to its des- balls, that the gastric juice of rumitination, is more complex, indeed, nating animals, such as the sheep and and intricate; but, in the midst of the ox, speedily dissolves vegetables, complication and intricacy, as evi but makes no impression upon anident and certain as is the apparatus mal bodies. This gastric juice, even of cocks, pipes, tunnels for transfer- of graminivorous birds, will not act ring the cyder from one vessel to upon the grain whilst whole and enanother, of barrels and bottles for tire. In performing the experiment
of digestion with the gastric juice in of turning the pupil to the object. vessels, the grain must be crushed This great defect is however pero and bruised before it be submitted fectly compensated, and by a mechato the inenstruum, that is to say, must nisni which we should not suspect; undergo by art, without the body, the eye is a multiplyiog glass, with the preparatory action which the a lense looking in every direction, gizzard exerts upon it within the and catching every objeci..... body, or no digestion will take place. * Adams tells us, that fourteen So strict is the relation between the hundred of these reticulations have offices assigned to the digestive or- been counted in, the two eyes of a gan; between the mechanical ope. drone bee." p. 303. ration and the chymnical process." The number of eyes in a spider, p. 284–289.
and the curious formation of the eye The relation existing in the swan of the camelion, is described. The and the mole to their modes of life is snail, the muscle, and the cockle are pointed out, and with these instances noticed, and the lobster comes under the chapter concludes.
consideration. “A lobster has a dif. Chap. XVI. Compensation. ficulty in its constitution so great,
The term is thus defined. Com- that one could hardly conjecture bepensation is a species of relation. It fore hand how nature would dispose is relation when the defects of one of it. In most animals the skio grows part or one organ are supplied by the with their growth. If, instead of a structure of another part, or of ano- soft skin, there be a shell, still it ad. ther organ.
mits of a gradual enlargement. If The following instances are no- the shell, as in the tortoise, consist of ticed.
several pieces, the accession of subThe short unbending neck of the stance is made at the sutures. Bielephant is compensated by the length valve shells grow bigger by receiving and flexibility of his proboscis. Here an accretion at their edge: it is the follows an accurate description of the same with spiral shells at their mouth. necessity, use, and nature of this or- The simplicity of their form admits gan.
of this. But the lobster's shell being The hook in the wing of a bat. applied to the limbs of the body, as The crane kind are to live and seek well as to the body itself, allow's not their food amongst the waters; yet either of the modes of growth which having no web-feet, are incapable of are observed to take place in other swimming: To make up for this de. shells. Its hardness resists expanficiency, they are furnished with long sion, and its complexity renders it legs for wading, or long bills for grop- incapable of increasing its size by ading, and usually with both. This is dition of substances to its edge. How compensation. • The common parrot then was the growth of the lobster to has, in the structure of its beak, both be provided for? Was room to be an inconveniency and a compensa- made for it in the old shell, or was it to tion for it. The upper bill of the be successively titted with new ones? parrot is so much hooked, and so If a change of shell became necesmuch overlaps the lower, that if, as sary, how was the lobster to extricate in other birds, the lower chap alone himself from his present confinement? had motion, the bird could scarcely How was he to uncase his buckler, or gape wide enough to receive its food; draw his legs out of his boots ? The yet this book and overlapping of the process, which fishermen have ob. bill could not be spared, for it forms served to take place, is as follows. the very instrument by which the At certain seasons the shell of the bird climbs, to say nothing of the use lobster grows soft; the animal swells he makes of it in breaking nuts, and its body; the seams open, and the the hard substances upon which it claws burst at the joints. When the feeds. How therefore has nature pro- shell is thus become loose upon the vided for the opening of this occlud. body, the animal makes a second efed mouth? By making the upper fort, and by a tremulous spasmodic chap moveable as well as the lower." motion casts it off. In this state the p. 301, 302.
liberated but defenceless fish retires The spider's web. “ The eye of in- into holes in the rock. The released sects, which in many species is fixed; body now suddenly pushes its growth. and consequently without the power in about eight-and-forty hours a fresh
concretion of humour upon the sur" is a propensity, prior to experience, face, i. e. a new shell, is formed, and independent of instruction. We adapted in every part to the in- contend, that it is by instinct that the creased dimensions of the animal. sexes of animals seek each other; This wonderful mutation is repeated that animals cherish their offspring; every year." p. 306–308.
that the young quadruped is directed The deficiency of teeth in quadru- to the teat of its dam; that birds peds is compensated for in rumina. build their nests, and brood with so tion, and in some birds by a gizzard; much patience upon their eggs; that and the author closes with reptiles: insects, which do not sit upon their “ A very numerous and comprehen- eggs, deposit them in these particular sive tribe of terrestrial animals are situations, in which the young, when entirely without feet, yet locomo- hatched, find their appropriate food; tive, and in a very considerable de that it is instinct which carries the gree swift in their motion. How is salmon, and some other fish, out of the the want of feet compensated ? It is sea into rivers, for the purpose of done by the muscles and fibres of the shedding their spawn in fresh water." trunk.
p. 324, 325. Chap. XVII. The relation of ani. A number of instances are adduced mated bodies to inanimated nature. with very appropriate observations.
Here the author shews the relation Chap. XIX. Of insects. of the wings of birds to air, and the This chapter proves, in a variety of fins of fish to water. The animal ear cases, that there are many contrivandepends for its use, as well as the ces in the bodies of insects, neither organs of speech and voice, upon the dubious in their use, nor obscure in peculiar qualities of the fluid in which their structure, and most properly the animal is immersed. In further mechanical : the elytra or scaly. discussing the subject of appropria- wings of the beetle to preserve the tion, the author observes: “Yet the gauze wings which they cover; the element of light and organ of vision, awl or borer, with which many sorte however related in their office and of flies pierce different things to form use, have no connection whatever in a depository for their eggs; the their original. The action of rays stings of some insects, particularly of of light upon the surfaces of animals the bee, which is accuraiely described; has no tendency to breed eyes in their the proboscis of some insects, its heads. The sun might shine for ever construction and use ; the metamorupon living bodies without the small. phosis of insects from grubs into est approach towards producing the moths and flies. Of this the following sense of sight. On the other hand curious account is given.“ In some also, the animal eye does not generate, species the proboscis, the antennnæ, or emit light." P. 317, 318.
the limbs and wings of the fly, have The proportioning of one thing to been observed to be folded up within another is next considered, as in the the body of the caterpillar, and with size of animals, of the human animal such a nicety as to occupy a small especially, when considered with re- space only under the two first rings. spect to other animals, or to the This being so, the outermost animal, plants which grow around him, is which besides its own proper chasuch as a regard to his conveniency racter, serves as an integument to the would bave pointed out. A giant or other two, being furthest advanced, a pigmy could not have milked dies as we suppose, and drops off first. goats, reaped corn, or mowed grass; The second, the pupa or chrysalis, we may add, could not have rode a then offers itself to observation. This horse, trained a vine, shorn a sheep, also, in its turn, dies; its dead and with the saine bodily ease as we do, brittle husk falls to pieces, and makes if at all. A pigmy would have been way for the appearance of the fly or lost among rushes, or carried off by moth. Now, if this be the case, or birds of prey.” p. 318.
indeed whatever explication be aThe suitableness of the earth and dopted, we have a prospective con. sea to their several inhabitants is also trivance of the most curious kind : noticed ; and the last instance is the we have organizations three deep, yet relation of sleep to night.
a vascular system, which supplies nu. Chap. XVIII. Instincts.
trition, growth, and life to all of them “ An instinct,” says the author, together." P, 355.
And the preservation of the eggs this account to the test of repeated of insects.
and familiar observation, I am unable The above observations belonging to say. Its leaves are jointed, and to the whole insect tribe, or to a great surrounded with two rows of strong part of them, the author proceeds to prickles; their surfaces covered with observations limited to fewer species. à number of minute glands, which se He notices, the organization in the crete a sweet liquor, that allures the abdomen of the silk-worm or spider, approach of flies. When these parts whereby these insects form the thiread, are touched by the legs of flies, the is as incontestably mechanical as a two lobes of the leaf instantly spring wire-drawer's mill
. The relation of up, the rows of prickles lock themthe wax to the honey in bees; the selves fast together, and squeeze the brushes to the fore and binder feet of unwary animal to death *. Here, una fly, with which the animal dresses der a new model, we recognize the its body; the light in the tail of the ancient plan of nature ; viz. the sels. glow worm, which is allowed by na tion of parts and provisions to one turalists to be both chemical and me another, to a common office, and to chanical, its nature and design, are the utility of the organized body to pointed out. The author observes, which they belong. The attracting that “our discoveries, or rather our syrup, the rows of strong prickles projects, turn out to be imitations of their position so as to interlock the nature. Some years ago a plan was joints of the leaves, and what is suggested of producing propulsion by more than the rest, that singular irrire-action in this way. By the force of a tability of their surfaces by which steam engine a stream of water was to they close at a touch, all bear a cod be shot out of the stern of a boat, the tributory part in producing an effect, impulse of which stream upon the wa. connected either with the desence or ter in the river was to push the boat with the nutrition of the plant." forward; it is, in truth, the principle p. 396, 397. by which sky-rockets ascend into the Chap. XXI. The elements. air ... ... Now, if naturalists The uses of the elements are exare to be believed, it is exactly the plained and illustrated in some strikdevice which nature bas made use of ing particulars. for the motion of some species of Chap. XXII. Astronomy. aquatic insects. The larva of the Chap. XXIII. Of the personality dragon-fly, according to Adams, swims of the Deity. by ejecting water from its tail; is The author explains the subject of driven forward by the re-action of this chapter in the following manner. water in the pool upon the current “ Contrivance, if established. appears issuing in a direction backward from to me to prove every thing which we its body.” p. 364.
wish to prove. Amongst other things The expedient of air balloons, so it proves the personality of the Deity new to us, proves to be no other than as distinguished from what is somewhat the Author of nature has em- times called nature, sometimes called ployed in the gossamer spider.
a principle, which terms, in the Some observations upon animals mouths of those who use them philo. covered with shells, belonging both to sophically, seem to be intended to land and water, follow, and the chap- admit and to express an efficacy, but ter closes with remarks upon the im- to exclude and to deny a personal mense variety and number of this agency. Now that which can conclass of animals.
trive, which can design, must be a Chap. XX. Of plants.
person. These capacities constitute The author gives an accurate ac- personality, for they imply consciouscount of the nature, growth, and ness and thought; they require that means used to preserve the seed, which can perceive an end or purspecified in many instances. The pose, as well as the power of provide mechanism of climbing plants is ing means, and of directing them to particularly noticed, and some cu their end ; they require a centre in rious plants are described, the last of which perceptions unite, and from which is the “dionea muscipula, an which volitions flow; which is mind. extraordinary American plant. Whe. The acts of a mind prove the existther we be yet enough acquainted with the plant to bring every part of * Smellie's Pbil. of Nat. Hist, vol I. p. 3.
ence of a mind: and in whatever a world. This fifth sense makes the mind resides is a person. The seat animal what the human animal is : of intellect is a person. We have no but to infer that possibility stops here, authority to limit the properties of that either this fifth sense is the last mind to any particular corporeal sense, or that the five comprehend form, or to any particular circum- all existence, is just as unwarrantable scription of space. These properties a conclusion as that which might subsist in created nature, under a have been made by any of the dif. great variety of sensible forms. Also ferent species which possessed fewer, every animated being has its senso. or even by that, if such there be, rium, that is, a certain portion of which possessed only one. The conspace, within which perception and clusion of the one 'sense animal, and volition are exerted. This sphere the conclusion of the five sense animay be enlarged to an indefinite ex. mal, stand upon the same authority. tent; may comprehend the universe; There may be more and other senses and being so imagined, may serve to than those which we have. There furnish us with as good a notion as may be senses suited to the percepwe are capable of forming of the im- tion of the power, properties, and mensity of the divine nature, i. ci of a substance of spirits. These may be. Being, infinite, as well in essence as long to higher orders of rational in power ; yet nevertheless a per- agents; for there is not the smallest
reason to suppose that we are the " • No man hath seen God at any highest, or that the scale of creation time.' And this I believe makes slops with us."... p: 439, 442. the great difficulty. Now it is a dif The proposition that "the great hculty which chiefly arises from our energies of nature are known to us not duly estimating the state of our only by their effects" is next illusfaculties. The Deity, it is true, is trated, and the author proceeds to the object of none of our senses; but expose and confute the false reasonreflect what limited capacities animal ings of many pbilosophers, concluding senses are. Many animals seem to thus : Upon the whole; after ali have but one sense, or perhaps two the struggles of a reluctant philosoat the most, touch and taste. 'Ought phy, the necessary resort is to a such an animal to conclude against Deity. The marks of design are the existence of smells, sounds, and too strong to be got over. Design colours ? To another species is given must have had a designer. That dethe sense of smelling. This is an ad- signer must have been a person. vance in the knowledge of the pow. That person is God.". p. 473. ers and properties of nature ; but, if Chap. XXIV. Of the natural attrithis favoured animal should inter butes of the Deity. from its superiority over the class In this chapter we find the followlast described, that it perceived every ing observation. “It is one of the thing that was perceptible in nature, advantages of the revelations which it is known to us, though perhaps not we acknowledge, that, whilst they suspected by the animal itself, that it reject idolatry with its many perniproceeded upon a false and presump- cious accompaniments, they introtuous estiinate of its faculties. 'lo duce the Deity to human apprehenanother is added the sense of hear- sion, under an idea more personal, ing, which lets in a class of sensa more determinate, more within its tions entirely unconceived by the compass than the theology of nature animal last spoken of; not only dis can do; and this they do by repretinct but remote from any it had ever senting him exclusively under the experienced, and greatly superior to relation in which he stands to ourthem. Yet this last animal has no selves; and, for the inost part, under more ground for believing, that its some precise character, resulting senses comprehend all things and all from that relation, or from the history properties of things, which exist, than of his providences, which method might have been claimed by the suits the span of our intellects much tribes of animals beneath it: for we better than the universality which know that it is still possible to possess enters into the idea of God, as deanother sense, that of sight, which duced from the views of nature. shi xisclose to the percipient a new When, therefore, these representations