whilst he acted for this, and made his way to temporal things by descanting on the value of those that are eternal. He belonged to a bad school; and in such a case it is no small compliment to say that he retained in his manners to the very last a good deal of the gentleman and the scholar.

ART. V.. The Philosophy of Zoology; or, a General View of the Structure, Functions and Classification of Animals. By John Fleming, D.D. Minister of Flisk, Fifeshire, F.R.S.E. Member of the Wernerian Society, &c. 2 vols. 17. 10s. Constable, Edinburgh. 1822.

THE work whose title we have just given is one of a nature hitherto much wanted; and this in several respects. In the first place, previously to the present publication there has not been extant in our language any good scientific introduction to the extensive and important study of general zoology and physiology. In this point of view we think Dr. Fleming has done considerable service to the public by giving a compendious yet sufficiently detailed system of the science. He has first treated of general physiology and comparative anatomy; and then proceeded to a survey of the whole animal kingdom.

In another point of view we also congratulate the public on the appearance of this work, inasmuch as too many which have appeared of late years on similar subjects have clearly displayed, if not made their ruling principle, a desire to impugn and calumniate the most sacred doctrines of revelation; and to overthrow the most fundamental positions on which the whole superstructure of religion not only revealed but natural also is built. The work before us exhibits a character widely different from these. The author seems to have made it a point of particular attention, to take every opportunity which his subject afforded for inculcating a respect for religion; and for pointing out those various and striking arguments which the science he is treating of so abundantly sup plies in support of it.

To give any thing like a detailed analysis of a work of this description, would be unsuitable both to the nature and limits of our journal: and to give less than such an account would not be to do the work justice. We conceive, therefore, that we shall be making our review of it at once more profitable and less uninteresting, if we confine our remarks to

a consideration of the work, in the latter of the two points of view in which, we have first remarked, its merits may be contemplated. We shall endeavour to exhibit to our readers the most prominent of those parts of the book where the author, by his cautious and truly philosophical mode of investigating and describing some parts of the economy of the animated world, sufficiently and ably refutes those unfounded theories, and most completely unphilosophical hypotheses, which have been palmed upon the world as the results of genuine science, by a set of superficial smatterers, in their obviously gratuitous assumption of a material cause for vital and intellectual phenomena,

Dr. Fleming after treating of the divisions into which natural science resolves itself, proceeds to the distribution of natural objects into the two grand classes of organized and inorganic productions. He traces the chain of existence through all the various links of which it is composed, from the fossil to the animal: and discriminates with great accuracy the various distinctions to be drawn between its different parts.

He next proceeds to examine the peculiar character of organized bodies. And in so doing the first and most prominent object is the nature of what we term the vital principle.

"When we examine a plant or an animal as near to the origin of its existence as possible; we witness its embryo or germ, small indeed, but possessing a power capable of developing in succession the destined phenomena of existence. By means of this power the germ is able to attract towards it particles of inanimate matter, and bestow on them an arrangement widely different from that which the laws of chemistry and mechanics would have assigned them. The same power not only attracts those particles and preserves them in their new situation, but is continually engaged in removing those which by their presence might prevent or otherwise derange its operations." P. 8.

He then goes on to point out that the vital principle is limited in each species to a particular magnitude of body, a peculiar form, structure, and chemical composition, as also an assignable duration. The faculty named irritability seems to be the most remarkable feature accompanying organic life. It appears to reside in the fibrous parts and is imperfectly displayed even by some vegetables: whilst in animals it seems closely connected with the display of muscular power, and the exercise of almost all the faculties.

Instinct is another characteristic, of organic life; and in its comprehensive sense is enjoyed by plants as well as ani

mals. It regulates the supply of nutriment; obviates difficulties; repairs injuries; and leads to the means of procreating the species; powers, the partial display of which in vegetables is highly curious, and points out many close analogies between them and the animal kingdom. It is from the detailed consideration of all these particulars that our author is led to some further remarks on the nature of the vital principle, which their excellence induces us now to copy.

"These different operations of living beings which we have thus briefly enumerated, can never be regarded as the effect of their peculiar organization. The organs are formed according to a uniform and determined plan, from inorganic matter, collected from various sources, and arranged, according to the species, on different models. By what power then does this organization take place? And what is the nature of that principle which regulates animated beings? We have already taken notice of the laws by which it is regulated in the constitution, duration, and continuance of organized bodies. These make us acquainted with the existence of a principle different from any of those which the mechanical or chemical philosophers have investigated with so much success. This power has been denominated the living or vital principle; and the phenomena which it exhibits are included in our idea of life or vitality." P. 21.

The vital principle, whatever may be its nature, appears to be capable of residing only in bodies possessing a regularly organized structure. Our author points out the temporary nature of the connexion thus subsisting, and shews that it may be dissolved by a variety of circumstances. He enumerates the various conditions necessary for the existence of the vital principle so far as observation has detected them. They are these, 1. a parent; 2. moisture; 3. temperature; 4. atmospheric air; 5. nourishment. He then adverts to the consideration of the modifications of the vital principle, which seem to arise from the exact harmony being disturbed, which should exist between all the different parts and functions of organization. These ought, in order to the healthy continuance of life, to be so exactly regulated as to form, as it were, a system of perfect equilibrium. The undue predominance or deficiency of any function is what we term disease, and if it proceed beyond a certain limit, terminates in the complete interruption of the whole system of functions, and the death of the individual ensues. This tends to shew that the vital principle must be something more than a mere result of organization; because, besides organization, a certain other condition, viz. the proportion to be maintained between the various functions in their operations, is necessary in order to the continuance of life.

The distinctions between animals and vegetables; the general polity (as the author terms it) of nature in the mutual arrangement of the two kingdoms, and their dependence on each other; the chemical examination of the compounds which constitute the animal frame; the mechanical structure of the various parts; and a general, anatomical, and physiological survey of animal bodies, are the topics of successive discussion and are treated of in a clear, accurate, and sufficiently detailed manner. Amongst the various parts of the animal economy the author is lead to treat particularly of the muscles, and, closely connected with them, of the nerves and brain. The nervous system, whether considered in its structure simply, or in its functions, is one of the most curious and most complicated parts of physiology. This subject is first examined in regard to the structure of the brain and nerves. An anatomical view is given of the different parts of the brain, and the general structure of the spinal marrow, and the two systems of nerves which pervade the body. The modifications of this system are traced through the different gradations of animal existence, down to those classes where no such system can be detected. The comparison of the brain in different classes of animals is a most interesting and valuable topic of enquiry. This point has fortunately occupied the attention of one of the greatest physiologists of the age, M. Cuvier. From his researches our author has exhibited a compendious, but instructive table of the differences which characterize the structure of the brain in different classes. But the most generally interesting part of these results we conceive to be the following, which bear upon the question of the connection between organization and mind.

It appears that there exist certain relations between the faculties of animals, and the proportions of those parts of the brain which they possess in common.

"Thus the intelligence they possess appears more perfect in proportion to the volume of the appendix of the corpus striatum, which forms the vault of the hemisphere. Man has that part greater, more extended, and more reflected than the other animals. In proportion as we descend from man, we observe that it becomes smaller and smoother on the surface, and that the parts of the brain are less complicated with each other, but seem to be unfolded and spread out longitudinally. It even appears that certain parts assume, in all classes, forms which have a relation to particular qualities of animals: for example, the anterior tubercula quadrigemina of carps, which are the most feeble and least carnivorous of fishes, are proportionally larger than in the other genera, in the same manner as they are in the herbivorous quadrupeds.

By following these enquiries we may hope to obtain some knowledge of the particular uses of each of the parts of the brain.??

P. 151.

These remarks of M. Cuvier exhibit a valuable specimen of truly philosophical procedure in the enquiry after truth: and afford a striking contrast to the many crude and hasty speculations on similar points, which have led so many empty and superficial pretenders to science, into a variety of absurd, unfounded, and often most culpable theories, on subjects of the utmost importance, from their being so intimately connected with the prospects which mankind entertain with respect to their own nature, their obligations and their end.

We regret that our limits will not permit us to follow up our author through many excellent remarks connected with this part of the subject, but we must proceed.

Thus far he has considered the nervous system only in respect to its structure and nature: the next division of the subject relates to the same system when exhibited in action. And this part of the enquiry is one into which the most dangerously erroneous views have been introduced. The nervous system considered in action is a subject unquestionably the most interesting in the whole range of zoological science. Yet it is still involved in much obscurity, and will probably continue to be so unless new methods of observation shall be devised, and more rigorous induction practised. This the improving state of physiological science encourages us to hope may at some future time be the case. Meanwhile our author proceeds thus.

"That the brain is the organ to which the impressions produced by external objects are conveyed, and from which the excitements to motion in the different parts are propagated, has been demonstrated by observation and experiment. We have already stated the complicated structure of this organ, and the variety in the texture and situation of its different parts. What then are the uses of each? Physiologists have always been greatly divided in their opinions on this important subject." P. 153.

Some supposing that the seat of the intellectual operations must exist near the centre of the brain, have considered the pineal gland as the common sensorium.' Others have bestowed the same honour on other parts. Some on the aqueous fluid found in the ventricles. According to Gall and Spurzheim, the various operations have each their distinct portion of the brain as a peculiar organ. Other theories also of a similar description, and equally unsupported by facts, have been advanced by various other authors.