drupeds the aliment is first broken and bruised by mechanical instruments of mastication, viz. sharp spikes or hard knobs pressing against or rubbing upon one another: thus ground and comminuted it is carried by a pipe into the stomach, where it waits to undergo a great chymical action, which we call digestion; when digested, it is delivered through an orifice, which opens and shuts, as there is occasion, into the first intestine: there, after being mixed with proper ingredients, poured through a hole in the side of the vessel, it is further dissolved in this state the milk, chyle, or part which is wanted, and which is suited for animal nourishment, is strained off by the mouths of very small tubes opening into the cavity of the intes tines: thus freed from its grosser parts, the percolated fluid is carried by a long, winding, but traceable course, into the main stream of the old circulation, which conveys it, in its progress, to every part of the body. Now I say again, compare this with the process of a manufactory; with the making of cyder, for example; the bruising of apples in the mill, the squeezing of them when so bruised in the press, the fermentation in the vat, the bestowing of the liquor thus fermented in the hogsheads, the drawing off into bottles, the pouring out for use into the glass. Let any one shew me any difference between these two cases, as to the point of contrivance. That which is at present under our consideration, the relation' of the parts successively employed, is not more clear in the last case than in the first. The apt. ness of the jaws and teeth to prepare the food for the stomach is at least as manifest as that of the cyder mill to crush the apples for the press. The concoction of the food in the stomach is as necessary for its future use, as the fermentation of the steem in the vat is to the perfection of the liquor. The disposal of the aliment afterwards; the action and changes which it undergoes; the rout which it is made to take in order to its destination, is more complex, indeed, and intricate; but, in the midst of complication and intricacy, as evident and certain as is the apparatus of cocks, pipes, tunnels for transferring the cyder from one vessel to another, of barrels and bottles for

preserving it till fit for use, or for cups and glasses for bringing it, when wanted, to the lip of the consumer. The character of the machinery is in both cases this, that one part answers to another part, and both to the final result.

“This parallel between the alimentary operation, and some of the processes of art, might be carried further into detail. Spallanzani has remarked a circumstantial resemblance between the stomachs of gallinaceous fowls and the structure of corn-mills. Whilst the two sides of the gizzard perform the office of the mill-stones, the craw or crop supplies the place of the hopper. When our fowls are abundantly supplied with meat, they soon fill their craw; but it does not immediately pass thence into the gizzard; it always enters in very small quantities, in proportion to the progress of trituration in like manner as in a mill, a receiver is fixed above the two large stones which serve for grinding the corn, which receiver, although the corn be put into it by bushels, allows the grain to dribble only in small quantities into the central hole in the upper mill

stone.

But we have not done with the alimentary history. There subsists a general relation between the external organs of an animal, by which it procures its food, and the internal powers by which it digest it. Birds of prey by their talons and beaks are qualified to seize and devour many species, both of other birds, and of quadrupeds. The constitution of the stomach agrees exactly with the form of the members. The gastric juice of a bird of prey, of an owl, a falcon, or a kite, acts upon the animal fibre alone; will not act upon seeds or grasses at all. On the other hand, the conformation of the mouth of the sheep or the ox is suited for browsing upon herbage. Nothing about those animals is fitted for the pursuit of living prey. Accordingly it has been found by experiments, tried not many years ago with perforated balls, that the gastric juice of ruminating animals, such as the sheep and the ox, speedily dissolves vegetables, but makes no impression upon animal bodies. This gastric juice, even of graminivorous birds, will not act upon the grain whilst whole and entire. In performing the experiment

of digestion with the gastric juice in vessels, the grain must be crushed and bruised before it be submitted to the menstruum, that is to say, must undergo by art, without the body, the preparatory action which the gizzard exerts upon it within the body, or no digestion will take place. So strict is the relation between the offices assigned to the digestive or gan; between the mechanical operation and the chymical process." p. 284-289.

The relation existing in the swan and the mole to their modes of life is pointed out, and with these instances the chapter concludes.

Chap. XVI. Compensation.

The term is thus defined. Compensation is a species of relation. It is relation when the defects of one part or one organ are supplied by the structure of another part, or of another organ.

The following instances are noticed.

The short unbending neck of the elephant is compensated by the length and flexibility of his proboscis. Here follows an accurate description of the necessity, use, and nature of this organ.

The hook in the wing of a bat. The crane kind are to live and seek their food amongst the waters; yet having no web-feet, are incapable of swimming. To make up for this deficiency, they are furnished with long legs for wading, or iong bills for groping, and usually with both. This is compensation. The common parrot has, in the structure of its beak, both an inconveniency and a compensation for it. The upper bill of the parrot is so much hooked, and so much overlaps the lower, that if, as in other birds, the lower chap alone had motion, the bird could scarcely gape wide enough to receive its food; yet this hook and overlapping of the bill could not be spared, for it forms the very instrument by which the bird climbs, to say nothing of the use he makes of it in breaking nuts, and the hard substances upon which it feeds. How therefore has nature provided for the opening of this occluded mouth? By making the upper chap moveable as well as the lower." p. 301, 302.

The spider's web. "The eye of insects, which in many species is fixed; and consequently without the power

of turning the pupil to the object. This great defect is however perfectly compensated, and by a mechanism which we should not suspect; the eye is a multiplying glass, with a lense looking in every direction, and catching every object.....

"Adams tells us, that fourteen hundred of these reticulations have been counted in the two eyes of a drone bee." p. 303.

The number of eyes in a spider, and the curious formation of the eye of the camelion, is described. The snail, the muscle, and the cockle are noticed, and the lobster comes under consideration. “A lobster has a difficulty in its constitution so great, that one could hardly conjecture before hand how nature would dispose of it. In most animals the skin grows with their growth. If, instead of a soft skin, there be a shell, still it admits of a gradual enlargement. If the shell, as in the tortoise, consist of several pieces, the accession of substance is made at the sutures. Bivalve shells grow bigger by receiving an accretion at their edge: it is the same with spiral shells at their mouth. The simplicity of their form admits of this. But the lobster's shell being applied to the limbs of the body, as well as to the body itself, allows not either of the modes of growth which are observed to take place in other shells. Its hardness resists expansion, and its complexity renders it incapable of increasing its size by addition of substances to its edge. How then was the growth of the lobster to be provided for? Was room to be made for it in the old shell, or was it to be successively fitted with new ones? If a change of shell became neces◄ sary, how was the lobster to extricate himself from his present confinement? How was he to uncase his buckler, or draw his legs out of his boots? The process, which fishermen have observed to take place, is as follows. At certain seasons the shell of the lobster grows soft; the animal swells its body; the seams open, and the claws burst at the joints. When the shell is thus become loose upon the body, the animal makes a second effort, and by a tremulous spasmodic motion casts it off. In this state the liberated but defenceless fish retires into holes in the rock. The released body now suddenly pushes its growth. In about eight-and-forty hours a fresh

The above observations belonging to the whole insect tribe, or to a great part of them, the author proceeds to observations limited to fewer species. He notices, the organization in the abdomen of the silk-worm or spider, whereby these insects form the thread, is as incontestably mechanical as a wire-drawer's mill. The relation of the wax to the honey in bees; the brushes to the fore and hinder feet of a fly, with which the animal dresses its body; the light in the tail of the glow worm, which is allowed by naturalists to be both chemical and mechanical, its nature and design, are pointed out. The author observes, that our discoveries, or rather our projects, turn out to be imitations of nature. Some years ago a plan was suggested of producing propulsion by re-action in this way. By the force of a steam engine a stream of water was to be shot out of the stern of a boat, the impulse of which stream upon the water in the river was to push the boat forward; it is, in truth, the principle by which sky-rockets ascend into the air.. ... Now, if naturalists are to be believed, it is exactly the device which nature has made use of for the motion of some species of aquatic insects. The larva of the dragon-fly, according to Adams, swims by ejecting water from its tail; is driven forward by the re-action of water in the pool upon the current issuing in a direction backward from its body." p. 364.

The expedient of air balloons, so new to us, proves to be no other than what the Author of nature has employed in the gossamır spider.

Some observations upon animals covered with shells, belonging both to land and water, follow, and the chapter closes with remarks upon the immense variety and number of this class of animals.

Chap. XX. Of plants.

The author gives an accurate account of the nature, growth, and means used to preserve the seed, specified in many instances. The mechanism of climbing plants is particularly noticed, and some curious plants are described, the last of which is the "dionea muscipula, an extraordinary American plant. Whether we be yet enough acquainted with the plant to bring every part of

this account to the test of repeated and familiar observation, I am unable to say. Its leaves are jointed, and surrounded with two rows of strong prickles; their surfaces covered with a number of minute glands, which secrete a sweet liquor, that allures the approach of flies. When these parts are touched by the legs of flies, the two lobes of the leaf instantly spring up, the rows of prickles lock themselves fast together, and squeeze the unwary animal to death*. Here, under a new model, we recognize the ancient plan of nature; viz. the rela tion of parts and provisions to one another, to a common office, and to the utility of the organized body to which they belong. The attracting syrup, the rows of strong prickles, their position so as to interlock the joints of the leaves, and what is more than the rest, that singular irritability of their surfaces by which they close at a touch, all bear a con tributory part in producing an effect, connected either with the defence or with the nutrition of the plant." p. 396, 397.

Chap. XXI. The elements.

The uses of the elements are explained and illustrated in some striking particulars.

Chap. XXII. Astronomy. Chap. XXIII. Of the personality of the Deity.

The author explains the subject of this chapter in the following manner. "Contrivance, if established. appears to me to prove every thing which we wish to prove. Amongst other things it proves the personality of the Deity as distinguished from what is sometimes called nature, sometimes called a

principle, which terms, in the mouths of those who use them philo. sophically, seem to be intended to admit and to express an efficacy, but to exclude and to deny a personal agency. Now that which can con trive, which can design, must be a person. These capacities constitute personality, for they imply conscious ness and thought; they require that which can perceive an end or pur pose, as well as the power of providing means, and of directing them to their end; they require a centre in which perceptions unite, and from which volitions flow; which is mine. The acts of a mind prove the exist

Smellie's Phil. of Nat. Hist. vol I. på

ence of a mind: and in whatever a mind resides is a person. The seat of intellect is a person. We have no authority to limit the properties of mind to any particular corporeal form, or to any particular circumscription of space. These properties subsist in created nature, under a great variety of sensible forms. Also every animated being has its sensorium, that is, a certain portion of space, within which perception and volition are exerted. This sphere may be enlarged to an indefinite extent; may comprehend the universe; and being so imagined, may serve to furnish us with as good a notion as we are capable of forming of the immensity of the divine nature, i. e. of a Being, infinite, as well in essence as in power; yet nevertheless a per

son.

"No man hath seen God at any time.' And this I believe makes the great difficulty. Now it is a difficulty which chiefly arises from our not duly estimating the state of our faculties. The Deity, it is true, is the object of none of our senses: but reflect what limited capacities animal senses are. Many animals seem to have but one sense, or perhaps two at the most, touch and taste. Ought such an animal to conclude against the existence of smells, sounds, and colours? To another species is given the sense of smelling. This is an advance in the knowledge of the powers and properties of nature; but, if this favoured animal should infer from its superiority over the class last described, that it perceived every thing that was perceptible in nature, it is known to us, though perhaps not suspected by the animal itself, that it proceeded upon a false and presumptuous estimate of its faculties. To another is added the sense of hearing, which lets in a class of sensations entirely unconceived by the animal last spoken of; not only distinct but remote from any it had ever experienced, and greatly superior to them. Yet this last animal has no more ground for believing, that its senses comprehend all things and all properties of things, which exist, than might have been claimed by the tribes of animals beneath it: for we know that it is still possible to possess another sense, that of sight, which shall disclose to the percipient a new VOL. I.

world. This fifth sense makes the animal what the human animal is : but to infer that possibility stops here, that either this fifth sense is the last sense, or that the five comprehend all existence, is just as unwarrantable a conclusion as that which might have been made by any of the dif ferent species which possessed fewer, or even by that, if such there be, which possessed only one. The conclusion of the one sense animal, and the conclusion of the five sense animal, stand upon the same authority. There may be more and other senses than those which we have. There may be senses suited to the perception of the power, properties, and substance of spirits. These may belong to higher orders of rational agents; for there is not the smallest reason to suppose that we are the highest, or that the scale of creation stops with us." p. 439, 442.

The proposition that "the great energies of nature are known to us only by their effects" is next illustrated, and the author proceeds to expose and confute the false reasonings of many philosophers, concluding thus: Upon the whole; after all the struggles of a reluctant philosophy, the necessary resort is to a Deity. The marks of design are too strong to be got over. Design must have had a designer. That designer must have been a person. That person is God." p. 473.

Chap. XXIV. Of the natural attributes of the Deity.

In this chapter we find the following observation." It is one of the advantages of the revelations which we acknowledge, that, whilst they reject idolatry with its many pernicious accompaniments, they introduce the Deity to human apprehension, under an idea more personal, more determinate, more within its compass than the theology of nature can do; and this they do by representing him exclusively under the relation in which he stands to ourselves; and, for the most part, under some precise character, resulting from that relation, or from the history of his providences; which method suits the span of our intellects much better than the universality which enters into the idea of God, as deduced from the views of nature. When, therefore, these representations 4 F