writings of the gentleman so pointedly alluded to by Mr Lawrence, I shall attempt an apology for the fact of the former, and the hypothesis of the latter,-taking leave also to make a few remarks on some passages in Mr Lawrence's lectures.

Mr Hunter, in his Treatise on the Blood,' observes, An organ is a peculiar conformation of matter (let that matter be what it may), to answer some purpose, the operation of which is mechanical; but mere organization can do nothing: Even in mechanics, it must still have something corresponding to a living principle, namely, some power.

>

Mr Hunter then goes on to relate some experiments, to prove the existence of this principle, which, being generally known, it is unnecessary here to mention. Mr Lawrence prefers, after the French physiologists, for whom he appears to have a great partiality, the terms vital forces, living forces.' It is a rule in philosophy not to multiply causes unnecessarily; and as one cause would seem sufficient in the phenomena designated by the term life, living principle' is more appropriate. It has been consecrated too, if I may use the expression, by the genius of Hunter-and as Englishmen we ought to retain it. Mr Lawrence errs in classing the living principle with hypothesis. It is not an hypothesis, but a fact, whose existence is proved by the phenomena. Of the nature of this principle we know nothing. In the anatomical lectures delivered before the College of Sur geons in 1814, the lecturer conjectured, that the living principle of Mr Hunter might be a subtle mobile fluid, and this hypothesis he considered as both rational and probablc. Though I am no friend to hypotheses, for the reasons assigned by the great northern philosopher, yet that of the lecturer is, I conceive, neither irrational nor improbable, nor has it the smallest tendency to impede the progress of physiological investigation, For, though such an hypothesis as Hartley's, to account for perception and thought, be not only improbable but impossible, that of the lecturer is not only Bossible but probable; and, as every effect must have a cause, what more rational or probable than that certain phenomena of the living body should be occasioned by a subtle mobile fluid? Mr Lawrence has exercised his wit on the comparison of the subtle fluid to magnetism, electricity, &c.; and, in imitation of Hamlet, talks of a whale and a camel. He observes, that the existence of the magnetic, electric, and galvanic fluids, which is offered as a proof of the existence of a vital fluid, is as much a matter of doubt as that of the vital fluid itself. It is singular, also, that the vital principle should be like both magnetism and electricity, when these two are not like each other. It is true that the lecturer does

employ the comparison of electricity and magnetism,-that he does say there is an analogy between them; but I would ask, might he not have intended to say galvanism, though he used the term magnetism? And is it not generally (I know it is not universally) supposed by natural philosophers, that the phenomena of electricity, galvanism, &c. depend on a subtle fluid? But, admitting the anatomical lectures to contain some few faults, (and what human production is perfect ?) they are more than compensated by their great merits. They are eloquently written, their philosophy is of the best and purest kind, and the conclusion is every way worthy of the philosopher and the man.

Mr Lawrence, in his first lecture, observes, Our first step in the study of life is to examine the organs that are its material instruments.' This sentence would imply that life was something not material:-its organs, we know, are. The adjective material, therefore, if to be understood literally, and not metaphorically, is superfluous, and conveys a notion not, I presume, intended. Mr Lawrence having remarked that it would not be a matter of wonder that the monastic institutions of a barbarous age should contain no provisions for teaching natural science, adds,But what excuse shall we find for the modern universities, as they are called, of a nation which fancies itself the most enlightened in Europe? universities which totally neglect natural history and all its connected pursuits, as if they were no part of universal knowledge.' I feel as much concern as Mr Lawrence that there should be no provision in our universities for teaching natural history; but, with this defect in our system of education, and acknowledging our inferiority in this department of science, an impartial judge, I think, would still allow us to be the most enlightened nation in Europe. Whether it regards the philosophers and the statesmen, the pc.ts, the orators, and the historians she has produced, her theologians or her scholars, England need not shrink from a comparison with any modern nation. The neighbouring nation has never produced such men as Bacon, and Locke, and Newton, as Spenser, as Milton, or as Shakespeare,-as Porson or Horne Tooke,-as Sydenham, or John Hunter. No! it is not England, it is the neighbouring nation,' who fancies herself the most enlightened nation in Europe,' and who, like ancient Rome, considers all others as barbarous, compared with herself.

• Vital properties,' Mr Lawrence says, such as sensibility and irritability, are the means by which organization is capable of executing its purposes.' Vital properties, then, are the in

6

struments, and organization the agent? But, a little further, he observes, organization is the instrument, vital properties the acting power." How are we to reconcile the two opinions?Again, the particles which make up a living body,' we are told, are dependent on each other; they are all subject to the influence of a cause which animates them. This cause makes them all concur in the production of a common purpose,' &c. Afterwards we are informed, vital properties are the causes of vital functions, in the same way as chemical affinity is the cause of the combinations and decompositions exercised among the component particles of bodies,' &c. In the first quotation it will be perceived, that Mr Lawrence maintains the doctrine of Hunter, though he chuses not to give his animating cause the name of 'living principle;' in the last, that of Bichât;—and we have causes termed vital forces. ' If the lecturer erred in considering electricity and magnetism as similar, Mr Lawrence is not without fault in the following passage- The matter that surrounds us is divided into two great classes, living and dead; the latter is governed by physical laws, such as attraction, gravitation, chemical affinity. Attraction, gravitation, and chemical affinity, I always understood, were principles or powers, not laws; but which acted according to their respective laws. To call attraction, gravitation, &c. laws, therefore, is to speak incorrectly. Would any length of contemplation,' Mr Lawrence asks, have led you to discover that medullary substance is capable of sensation and of thought?' Certainly not; neither would any length of observation, I believe. For, were t possible to view the medullary portion of the living brain, we should not be authorized in regarding its agitations or motions as constituting actual sensation or thought. What! perception, thought, and volition, imagination, and memory, and reason, an arrangement and play of a set of atoms!! Mr Lawrence talks of an array of philosophical deduction;' but has he not himself been somewhat guilty of a parade of Germanic reference? Of the tendency of Mr Lawrence's philosophy and that of the lecturer, I shall say nothing:-I shall only observe, that that philosophy should be received with caution, whose princi ples are unfriendly to the best interests of mankind.

6

August 24, 1816.

PART II.

CRITICAL ANALYSIS.

I.

In Introduction to Comparative Anatomy and Physiology; being Two Introductory Lectures delivered at the Royal College of Surgeons, on the 21st and 25th of March 1816. By WILLIAM LAWRENCE, F. R. S.; Professor of Anatomy and Surgery to the College; Assistant-Surgeon to St Bartholomew's Hospital; Surgeon to Bethlehem and Bridewell Hospitals; and to the London Infirmary for Diseases of the Eye. 8vo. pp. 179. Callow, London, 1816.

We have much pleasure in embracing the earliest opportuty of introducing these eloquent and scientific Lectures to the notice of our readers, who, we doubt not, will derive the same instruction and gratification from the perusal which we have obtained. They were not composed, it appears, with a view to publication, but have been now printed, in consequence of repeated applications to the author for copies of them. He has added, however, numerous notes and references, which greatly enhance the value of the Lectures; in as much as they constitute an ample catalogue of all the best sources of informa tion on the subjects here discussed.

The first Lecture, which comprehends the Objects and History of Comparative Anatomy,' is rendered particularly valuable by this great store of reference to all the successive discoveries, and to the details of particular facts, which have been presented to the public in various countries and languages. It opens with a warm eulogium on the author's colleague and early preceptor, Mr Abernethy, and with an apology for the imperfections of

the course, from the short time for preparation, which had been allowed him; and then proceeds to state the value and objects of comparative anatomy. He observes, that the first step in the study of life, or the science of physiology, is to examine the organs which are the instruments of life; but that it is absolutely necessary to extend this examination beyond the structure of man or any one animal, to view them under all their modificacations and combinations, in order to ascertain what is essential in each.

The connexion and mutual influences of the various organs op. pose great and insuperable obstacles to our knowledge of the precise effect and importance of each. Here comparative anatomy comes to our aid: we find, in the various classes of animals, almost every possible combination of organs, and there is no organ which is not wanting in some class or other. The effect of such combinations and privations cannot but illustrate the nature and operations of the part in question. Fishes have no tympanum, nor external ear; insects no circulating system; many of the lower orders no brain nor nervous system. p. 10.

The author then remarks, that, if we confine our investigations to man, or the more complicated animals, we should be led to the most erroneous conclusions respecting the nature of vitality. A slight injury of the brain will destroy a man or a mammiferous quadruped; while the removal of the whole cranial contents is by no means suddenly fatal in the frog, turtle, and other reptiles. A tortoise lived six months after the skull was opened, and the whole brain removed by Redi. Frogs and newts lived three, four, and five days, after being deprived of their brain by Spallanzani, and leapt, ran, swam, &c. after their hearts were cut out, and lived forty-eight hours. The contrast in the state of vitality in the lower and more simple animals, with that of man and animals of more complicated structure, where the various organs are connected by numerous sympathies, is remarkably illustrated in the reproductive powers of the former, by which lost and mutilated parts are restored. In man and the animals nearly allied to him these powers, though limited, are considerable; as the union of bones and muscles divided by accident, and the restoration of their functions demonstrate; but in the lower order of animals there are scarcely any bounds to this reproductive power.

The lower we descend in the scale of beings, the more surpris ing are the manifestations of this reproductive faculty. The large claws of the crab and lobster, and the entire limbs or tail of the newt,