THE

ENGLISH REVIEW,

For MAY 1790.

ART. I. The Philofophy of Natural Hiftory. By William Smellie, Member of the Antiquarian and Royal Societies of Edinburgh. 4to. l. Is. boards. Edinburgh, printed: fold by Cadell, · London. 1790.

THE ftudy of nature is the moft delightful that can engage the attention of man. That beauty, that order, that fymmetry, which run through the works of creation, footh the turbulence of paffion, excite tender and placid emotions, and fill the feeling and contemplative mind with rapturous joy. Far different is the scene which human life prefents. Man, the tyrant of the universe, has violated the fair form of the world, and created confufion, and anarchy, and vice. The introduction of property, the divifion of ranks in fociety, the amazing extenfion of arts and commerce, have deftroyed the primeval manners, and contributed to the degradation of the human race. The ftudy of life, however useful, is certainly disgusting to an ingenuous mind, and has a manifeft tendency to weaken the force of moral obligation. From this chequered picture we gladly return to a more lovely scene. Our difpofitions receive a tincture from our ftudies and pursuits. The contemplation of nature attunes our fouls to harmony. That univerfal fyftem of gradation, and that fubordination of the parts to the whole, teach contentment with our fituation, and refignation to the Divine Will. We leave the habitation of groveling mortals, and, for a time, refpire a purer air.

ENG. REV. VOL. XV. MAY 1790.

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But the fubject of natural history is locked up in foreign or dead languages, and obscured with a farrago of barbarous names and indelicate illufions. To explore these rich mines, and to extract and refine the coarse ore, is to render an essential service to mankind. The ftudy is easy and attracting, and is equally accommodated to the youth of both fexes. Several works of this kind have been composed; but they have been generally defective in method or elegance. Ray, in the end of last century, and Derham in the beginning of the prefent, published treatifes of this popular nature; but the uncouth manner, the confufed arrangement, and the unpolished language, were equally forbidding, and their productions have fallen into oblivion. The · Abbé Le Pluche was more fuccefsful; his Spectacle de la Nature is even now read with confiderable pleasure. But the author is limited in his views, and extremely fuperficial. The only good work of the kind, with which we are acquainted, is the Contemplation de la Nature of Bonnet; and it deferves our higheft commendation. It is at once clear, elegant, and profound. The author takes an ample range, and his views are extenfive, and fometimes fublime. His diction is smooth and perfpicuous, and through the whole he breathes an air of beneficence and piety.

We confider the work now before us as a valuable present to the public. It furnishes the moft rational entertainment, and mingles, in a remarkable degree, the useful with the pleasant. It contains information that is various, elegant, and important. The method of treating it is clear and natural. The language, though fometimes perhaps diffuse and nerveless, is, upon the whole, fimple, correct, and perfpicuous. To novelty of facts, or originality of views, Mr. Smellie does not indeed pretend; but, in the felection of his materials, he difplays judgment and tafte. Like his friend, the late ingenious Lord Kaims, he discovers a fondnefs for investigating final caufes; a difpofition which, though hardly confiftent with the cautious fpirit of accurate philofophy, gives a favourable turn to the mind, and is peculiarly pleafing to youth. And in an age when a fuperficial knowledge pervades every rank, we doubt not that this work will be read with avidity.

In the first chapter, Mr. Smellie confiders the diftinguishing characters of animals, plants, and minerals, and the analogies which fubfift between them. The productions of nature afcend by gradual and imperceptible fteps. Those claffes which, at first fight, appear to be fo widely removed, are found, upon a clofer examination, to be feparated by no precife and determinate boundary. Hence definitions are useless and futile. In every circumftance plants, to a certain degree, refemble animals. The ftructure and irritability of parts, and the power of performing

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The

certain motions, are in fome measure common to both. delicate fhrink of the fenfitive plant has long been the subject of wonder and furprife. The moving plant, a native of the EastIndies, is affected by the mere impulfe of the folar rays. During the night, or in cold and cloudy weather, it is ftill and torpid; but when the fun fhines it is enlivened, and moves its leaves brifkly in all directions. The Venus' fly-trap, an American plant, is of a very fingular kind. Its leaves are furnished with a double row of prickles, with which it feizes and tranffixes the fmall infects that approach it. The fleep of plants is performed varioufly, and in a manner the beft adapted to their particular ftructure. The leaves of the tamarind-tree contract round the tender fruit, and protect it from the nocturnal cold. The leaves of the chickweed, the fwallow-wort, the orach, &c. are disposed in pairs, and during the night they rife, join at the top, and conceal the flowers. The leaves of the Indian mallow, the ayenia, and the tree-primrose, are placed alternately. Though horizontal, or even depending during the day, they rife at the approach of night, and embrace the ftem. In the same manner the nightshade, and the Egyptian vetch, erect their leaves during the night. The young buds of the white lupine are protected by the pendulous state of the leaves.-Plants have a fingular power of accommodating themselves to their fituation, and of recovering their original pofition. In fome inftances they seem to be actuated by the principle of choice, and almost capable of reflection:

• When trees grow near a ditch, the roots which proceed in a direction that would neceffarily bring them into the open air, instead of continuing this noxious progrefs, fink below the level of the ditch, then fhoot acrofs, and regain the foil on the oppofite fide. When the root is uncovered, without expofing it to much heat, and a wet fponge is placed near it, but in a different direction from that in which the root is proceeding, in a fhort time the root turns towards the sponge. In this manner the direction of the roots may be varied at pleasure. All plants make the ftrongest efforts by inclining, turning, and even twifting, their ftems and branches, to efcape from darkness and fhade, and to procure the influences of the fun. Place a wet fponge under the leaves of a tree, they foon bend downward, and endeavour to apply their inferior furfaces to the sponge. If a veffel of water be placed within fix inches of a growing cucumber, in twenty-four hours the cucumber alters the direction of its branches, bends either to the right or left, and never ftops till it comes in contact with the water. When a pole is placed at a confiderable distance from an unfupported vine, the branches of which are proceeding in a contrary direction from that of the pole, in a short time it alters its course, and ftops not till it clings around the pole.'

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Mr. Smellie proceeds to trace the analogy between plants and animals in the feveral points of sructure and organs, growth and nourishment, diffemination and decay.

1. Structure and organs. An accurate and distinct account occurs of that fingular being the polypus:

His body confifts of a fingle tube, with long tentacula, or arms, at one extremity, by which it feizes fmall worms, and conveys them to its mouth. It has no proper head, heart, ftomach, or intestines of any kind. This fimplicity of ftructure gives rife to an equal fimplicity in the economy and functions of the animal. The polypus, though it has not the diftinction of fex, is extremely prolific. When about to multiply, a fmall protuberance or bud appears on the furface of its body. This bud gradually fwells and extends. It includes not a young polypus, but is the real animal in miniature, united to the mother as a fucker to the parent-tree. The food taken by the mother paffes into the young by means of a communicating aperture. When the shooting polypus has acquired a certain growth, this aperture gradually clofes, and the young drops off, to multiply its ipecies in the fame manner. As every part of a polypus is capable of fending off fhoots, it often happens that the young, before parting from the mother, begin to fhoot; and the parent animal carries feveral generations on her own body. There is another fingularity in the hiftory of the polypus. When cut to pieces in every direction fancy can fuggeft, it not only continues to exift, but each fection foon becomes an animal of the fame kind. What is ftill more furprifing, when inverted as a man inverts the finger of a glove, the polypus feems to have fuffered no material injury. M. Trembley, in the course of his experiments, difcovered that different portions of one polypus could be ingrafted on another. He gave fcope to his fancy, and, by repeatedly fplitting the head and part of the body, formed hydras more complicated than ever ftruck the imagination of the moft romantic fabulifts.'

Vegetables are, like animals, compofed of a series of veffels. The bark confifts of the cortex or exterior covering, the parenchyma, a pulpy fubftance formed by a variety of folliculi, and the liber or rind, which, towards the end of autumn, coalefces with the wood, and acquires the fame confiftence. The pith is a congeries of air and fap veffels, interwoven like gauze. It continually diminishes, because a part dries and incorporates with the general mafs. The wood confifts of a dense compact ligneous matter, and a porous pulpy parenchyma. The same structure extends through every part of a vegetable; and the roots, the branches, and the leaves, however unlike in appearance, are fimilar in their texture. The afcenfion of fap is affifted by capillary attraction, and the action of the air veffels or trachea; but these causes are not alone adequate to the effect. The great fource of motion is the principle of life inherent in vegetables, and which is excited and ftimulated by the application of warmth.

The

The analogy between the circulation of the blood in animals is not indeed complete; for the fap rifes vigorously in the day, when the plant is cherished by the enlivening rays of the fun, and again defcends during the night. The pith of vegetables resembles the spinal marrow and brain, the great feat of life. The leaves are expiratory organs, and fupply the place of lungs. The branches, like the arms and tentacula of animals, ferve for support and defence. Bones, as well as wood, confift of concentric layers. The graffes differ confiderably from other plants in their structure. Their tubular and knotted form gives them ftrength to refift the violence of the wind. They resemble the polypus and tænia. Succulent vegetables bear an analogy to worms, caterpillars, and soft infects.

2. Growth and nourishment. Animals grow by developement, vegetables by accretion. Water is the principal food of plants; which is abforbed by the fibres of the root, elaborated and converted into sap, and then conducted, by numberlefs veffels, to nourish the various parts. Seeds and embryos grow in the fame manner. A part of the grain is converted, by the process of vegetation, into a pulpy faccharine fubftance, which nourishes the infant plant, and the feminal leaves, by attracting air and moifture, affift the expanfion. The age of animals admits of great variety. Plants are annual, biennial, triennial, and pe rennial. Warmth and moderate moisture are equally favourable to vegetation and animal life. Some plants are confined to particular climates. The arctic bramble is only found in Norway and Canada. Others, as the chickweed, are diffused over the earth. The elephant is the native of warm regions, the reindeer inhabits only cold countries; but man is difperfed through all the varieties of climate. The rufh is an amphibious plant, the misletoe a parafite.-Accefs of air and exercife are neceffary to the health and vigour of vegetables as well as of animals. Plants, in confined fituations, become weak, dwarfish, and pallid.

3. Diffemination and decay. The distinction of animals into oviparous and viviparous is not fufficiently marked. Some poffefs the power of generating in both ways; nor is the prefence of eggs always neceffary to production. One fpecies of polypus multiplies its kind, by fending of fhoots; another, by splitting longitudinally; another by dividing into tranfverfe fections. The dart-millepes difcharges its young, by a fpontaneous feparation. The animalcules which appear in animal and vegetable infufions, multiply ad infinitum, by continual divifions and fibdivifions. The vine-fretter has been discovered to be capable of producing, without the influence of the male; and Bonnet has conducted the experiment through a fucceffion of nine gene

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