UC-NRLF ,,„|. B 3 121 afib CO CO M :rf Digitized by the Internet Archive in 2008 with funding from IVIicrosoft Corporation http://www.archive.org/details/disquisitiononnaOOwarrrich DISQUISITION NATURE AND PROPERTIES LIVING ANIMALS AN INQUIRY HOW FAR OUR KNOWLEDGE OF ANATOftlY AND PHYSIOLOGY IS CONSISTENT WITH THE BELIEF OF A SOUL AND A FUTURE LIFE, AND ON THE INTELLECTUAL DIFFERENCE BETWEEN MAN AND BRUTES. By GEORGE WARREN, Surgeon, LONDON: LONGMAN, REES, ORME, BROWN, AND GREEN, PATERNOSTER-ROW; AND T. BUTCHER, 108, REGENT-STREET. 1828. T. C. Hansard, Pater-nosfer-row Press. ADVERTISEMENT. THE Author has, in the following pages, abridged the matter of the different heads as far as could be done consistently with the Argu- ment. In no part has this been more necessary than in that portion coming under the head of Pathology, in which the leading features only of Disease could be taken conformably with the design of this work. It is, however, his inten- tion, at a future period, to treat of Disease in detached inquiries. 4, Albany Terrace, Regent's Park. WS75:<4^ CONTENTS. CHAP. I p. I £,ife — its difficulties — must he met as other suhjects — No rationale of Life hitherto formed — hence the little use of our physiological facts — Extract from Mr. Lawrence — Extract from Sir Charles 3forgan — Literest and consequence of Inquiry up to this period — General opinions on the subject may he divided into three classes — First class — Second class — Third class — These opinions considered relatively — Dilemma of the prese7it state of hnoiv ledge — The Liquiry must be simple and the latiguage perspicuous — Natural order of Liquiry. CHAP. II p. 18 Metaphysics. — On a faculty and an act — Illustrattoti — Perceptibility is self-evident — Perceptibility and Sensibility not the same — The acts of Perception and Sensation simultaneous but not identical — Illustra- tion — Faculties of retaining, discerning, comparing, compounding, and abstracting — Sameness of the intellectual principle — Faculty of Willing — Faculty of Passion and Affection — On the Anima or Soul — The word Animal an adjective — Soul and Mind have been confounded — Definite Ideas must be form- ed of the tiuo terms — Definition of Mind — Our ordi- nary manner of speaking is consistent icith this defi- nition — On the formation of Mind— Character — Definition of Life. CONTENTS. CHAP. Ill p. 3G Animal Sensibility — its modifications five — the orgatis of the Jive modifications — arteries and nerves essen- tial to Sensibility — on the arteries — on the nerves'— co7inecting observations — Proposition — Facts in support — An essential preliminary consideration — Sum or force of a SeJisation is deter7nined by three circu)nsta7ices — enumerated— fii'st circumstance con - sidered — second circumstance considered — third cir- cumstance considered — Conclusion cojicetming these three cii'cumstances — Several animal phenome^ia explained — Conclusion . CHAP. IV j9. 54 Assimilati7\g organs — the uses of food-taking— decomposition of the body questioned — The pre- servative principle of flesh, or Mr. Hunter's vital jrrinciple — i7iay be exhausted— -and again restored — What this principle is — Whence derived — Facts in support — On the required quantities of food — Con- clusion. CHAP. V p. 62 The Lungs — bring the blood into contact tuith the air — sup]wsedobfect of this — questioned — and disjn-oved — Animal heat — no fixed degree essential to life — the degree of heat an adventitious circimistance — source of heat and use of the Lungs — arginnent in supjjort — on media iifluencing the degree of heat — Fishes — Amphibia — Insects — Conclusion . CHAP. VI p. 74 Muscular motion — consists in the simple j^roperty of contracting — is dej^endent upon 7iervous agency — Electric fluid is capable of exciting muscles to con- CONTENTS. VU tract— Dr . lire's exiJeriment^—Argtiment and facts in support of the identity/ of electric fluid and the natural cause of muscular contraction—Concluding remarks. CHAP. VII p. 83 He-view of facts and proof of proposition — The simul- taneous existence and destruction of the physical pro- perties of living animals — A deary intelligible^ and rational view of a living animal— aiid of the animal creation generally — A practical inference. CHAP. VIII ;>. 92 Pathology.'-^ Its object — Inflammation — Fever — Typhus — a result of fever— its forms — Sea-scurvy — Fainting — Hectic fever — Consumption — Some other Diseases — Conclusion. CHAP. IX p. 107 Examination of the arguments in favour of Material- ism — M. Bichat's argumoit concerning organic and animal Sensibility— is sophistical — A physical no- tion of life has insuperable physical objections — The reasoning of Materialists upon cause and effect — is not sound — Contrary to the assertions of the Materialists, the Soul may be defined, is evidenced by the senses, and has palpable proof in its effects — The size of the Brain — gives no support to Mate- rialism — but is in direct opposition to it^^The pro- bable use of the brain — Conclusion — is in accordance with the possibility of a future life — and that as taught by the Christian Scriptures. CONTENTS. CHAP. X p. 133 To admit a Soul in all living creatures is not 2in- scrij}tural — Comparison of the hnite and human Soul — wherein they differ — Language — acquired before knowledge — uses of this — The act of abstract- ing, explained — is essential to religious knowledge — fFhp religion cannot be acquired by brutes — On the minds of savages — Conclusion, DISQUISITION, &c. CHAPTER I. Life — its difficulties — must be met as other subjects — No ratioiiale of Life hitherto formed — hence the little use of our physiological facts — Extract from Mr. Laivrence — Extract from Sir Charles Morgan — Literest and consequence of hiquiry up to this 'period — General opinions on the subject may be divided into three classes — First class — Second class — Third class — These opinions considered relatively — Dilemma of the present state of knowledge — The Inquiry must be simple and the language ' perspicuous — Natural order of Inquiry, In affixing a title to the following Treatise I have endeavoured to make this what the title of every book ought to be, an index to its contents. Nevertheless, a word or two upon the matter by way of introduction, may be here, without any unnecessary waste of time, well and usefully applied. The inquiries hitherto instituted by philosophers, whether anatomists, physiologists, chemists, naturalists, B or metaphysicians, although highly creditable to their industry and research, and essentially useful in commencing and forv/arding the in- vestigation of this matter, have not been suffi- ciently general or enlarged, to lead to that extended and uniform comprehension of the subject which constitutes a science. Their individual inquiries having been partial, and directed only to the attainment of knowledge concerning some particular organ or function connected with life, to the habits or forms of animals, to the physical and chemical laws of matter, or to the discussion of some dogma Connected with existence ; their detached portions of inquiry have been properly termed, anatomical, experimental, metaphysical, and natural inquiries, examinations, histories, or descriptions of animals. But in a Disquisition, may be embraced the whole range of inves- tigation, which reason with all her powers, aided by the experiments and observations of other men, can grasp concerning the subject; and upon that account I have used this term. Life or animalbeing, how imperfectly soever it may be understood, is that state of existence which man possesses in common with his fellow-inhabitants of this world of matter. It is essentially the same in all, but being much varied in form, and being also supported in every instance by a complication of functions, and the functions being varied in different ani- mals, as well from their situation as from their size and form, these circumstances have rendered the subject so difficult to be understood, that many, and indeed most, men, have considered it an impenetrable mystery ; and the superstitious fears of the multitude are ever ready to consider impious, any attempts to search into this, as they suppose, guarded secret. To investigate the nature of this being, is the province of a peculiar science ; which, however much it may be aided by other kinds of knowledge, must always remain a distinct species of art. Never- theless, the same principles which direct the investigation of other subjects, will be used here, and the result of the inquiry must be scrutinized with the same suspicion, and sub- mitted to the same severe tests of truth. Like all complicated subjects, in order to be under- stood, it must be considered in its several parts ; and hence an analytic inquiry into the properties of a living animal is the best, if not the only ra- tional method, of acquiring a knowledge of life ; and the degree of success in this pursuit, will be found to depend upon the nicety of analysis. B 2 Although great advances have of late years been made in animal chemistry, and in ascer- taining the functions of particular organs, and in tracing their influence in living bodies, yet there has not hitherto appeared anything like a rational explanation of animal existence : writ- ten works, professedly physiological, being little more than the enumeration of the partial inquiries of others, with a few unsuccessful attempts at establishing general principles. And the constant subject of complaint, expressed and felt by inquiring men, is the obscurity and mystery which accompanies life, when consider- ed in the whole, however clearly and intelligibly it may appear to have been demonstrated and perceived in its several parts. This apparent comprehension of life in its parts, and its hidden nature when considered in the whole, is much to be regretted, since it is in " the conjunction of truths which preserve the genuine tendency, and secure the efiicacy of each, " and not in the simple knowledge of a few isolated facts, that we must seek for intellectual satisfaction, or for practical and extensive usefulness. It has been wisely observed by a celebrated controversialist upon this subject (Mr. Law- rence), " that descriptions of particular animals, and surveys of detached districts, in the great kinfjdom of nature, are not so much wanted at present, as the assemblage and assortment of the facts already accumulated, and the employ- ment of them by some person to furnish the fundamental principles of the science of living nature. It is employment, and not mere pos- session, which gives a value to intellectual as well as material wealth. We have had work- men enough to toil in the mine and the quarry — they have raised an abundance of materials — and we now only wait for the architect who shall be able to employ them in constructing a temple suitable in majesty and simplicity to the divinity. " " Dissection," says the same author, ''and the various auxiliary processes employed by the anatomist, are the only means of learning the structure of living beings ; observation and experiment, the only sources of our knowledge of life. These are the tests or criteria on which we must depend, and to which we must always refer. No position respecting structure can be listened to, unless it admit of verification by appeal to anatomy ; no physiological state- ment deserves attention, unless it be confirmed by observation. " He also observes, " the multitude and variety of organs in the human body, the complexity of their structure, the modifications incidental to each, and their mutual influences, offer a most extensive field of investigation, requiring so much time and assiduity, so much caution and discrimination, that the qualities necessary to a successful pursuit of physiology cannot be often combined in one individual. " When to man (says he) we add all the living beings which fill every department of nature, and consider the diversities and new combinations by which they are enabled to fulfil their various destinies, it will be hardly figurative to say, that the objects of inquiry are infinite and inexhaustible. *' In this as in most other subjects, the quantity of solid instruction is an inconsiderable fraction of the accumulated mass. A few grains ■ of wheat are buried and lost amid heaps of chaff. For a few well-observed facts, rational deductions, and cautious generalizations, we have whole clouds of systems and doctrines, of speculations and fancies, built merely on the workings c the closet. workings of the imagination and the labours of Upon the imperfect conclusions drawn by individuals from their partial inquiries, it has been well observed by another writer (Sir C. Morgan) that, "in every thing that concerns vital action, there are so many points to con- sider, so many discounts and allowances to be made, before the result of experiments can be obtained with purity and precision, that almost every writer has given a different sum total to his labours. The chemist is not neces- sarily a good physiologist, nor the physiologist an accurate experimenter ; so that it is rare to find a person uniformly well qualified to discuss the questions which arise in these investigations. But, as every one relies on his own observations, theories have been formed by an abuse of induction from the partial results of individual inquiry, by almost every author who has written on the subject. " He also, viewing the numerous difficulties by which the subject is surrounded, says, *' Considered in insulation,the moral and physical history of man is an inextricable labyrinth. 8 His various and complicated functions refuse to submit to analysis, and the origin and end of his being are alike placed beyond the reach of definition and conjecture. " The subject has ever been one of deep interest, and a point of meditation and wonder to all preceding ages ; the philosophers of anti- quity having made it the constant theme of their speculations, Mobile of late years it has been most actively agitated and discussed both in this coun- try and abroad ; yet the speculations of the anci- ents, and the controversy of the moderns, instead of throwing out a light of knowledge, or giving any satisfaction to an inquiring mind, have only evinced the subtle ingenuity of the unsuccessful theorist, and tended to shew really how little the nature of life is understood ; while, by embarrassing the judgment with conflicting opinions, it has naturally led to the discourage- ment of attempts at a better system. Science generally, either directly or indi- rectly, is so connected with this subject, that nearly all philosophical writings may be con- sidered to bear upon it; but the more immediate and professed writers upon animal being, may be divided into three classes. The opinions of these differ, and their modes of reasoning have been those which they have thought best adapted to the support of their respective notions. Not one of these opinions, aided by- its accompanying arguments, is satisfactory ; nor is any thing conclusive established from either ; and the merit of each writer consists rather in confuting, or at least confounding, the opinion of another, than in establishing his own hypothesis. One class of these are they who contend that a living principle, having an existence in- dependent of the physical body, and endued with those faculties which constitute the mind, and being of an indestructible nature, is the life-giving principle to the animal. This opin- ion they argue for, upon the assumption of the moral agency of man (the only animal which these writers contemplate), by a species of reasoning which, considered as foreign to phy- sical reasoning, is termed metaphysical ; but many of its supporters advance the Jewish account of man's creation, and the general te- nour of the Christian Scriptures as its sole basis. Another class are they, who, perceiving that 10 the developement of the body precedes that of the mind, and that the mental faculties may- be suspended or impaired by corporeal in- jury, or disordered function ; and arguing that our knowledge upon this and all other subjects is confined to cause and effect, do maintain that every property of the living animal, per- ceptibility, v^^ill, mental development, and all the phenomena of life, are the result of organization, and that it is useless to seek any other explanation. And, as an argument against reasoning otherwise, they show the absurd- ities and errors into which men may be led, by taking up notions unsupported by facts, especially in the treatment of disease. These arguments, with a few others concerning phy- sical influence on conduct, have been used by some poets and philosophers, in opposition to the opinions of those who contend for a spi- ritual principle, corporeal subserviency, and future hopes. 1 cannot adopt a fairer method, or present a clearer view of the opinions of these writers, than by using the words of an intelligent author before quoted. " I see," says he, " the animal functions inseparable from the animal organs — first showing themselves when they 11 are first developed — coming to perfection as they are perfected — modified by their various affections— decaying as they decay, and finally ceasing as they are destroyed. *' Examine the mind, the grand prerogative of man. Where is the mind of the foetus ? where that of the child just born? Do we not see it actually built up before our eyes by the actions of the five external senses, and of the gradually-developed internal faculties ? Do we not trace it advancing by a slow pro- gress through infancy and childhood, to the perfect expansion of its faculties in the adult — annihilated for a time by a blow on the head, or the shedding of a little blood in apoplexy- decaying as the body declines in old age— and finally reduced to an amount hardly per- ceptible, when the body worn out by the mere exercise of the organs, reaches, by the simple operation of natural decay, that state of de- crepitude most aptly termed second child- hood?" "Where then shall we find proofs of the mind's independence on the bodily structure ? of that mind which, like the corporeal frame, is infantine m the child, manly in the adult, 12 sick and debilitated in disease, jDhrenzied or melancholy in the madman, enfeebled in the decline of life, doating in decrepitude, and an- nihilated by death? " Take away from the mind of man, or from that of any other animal, the operations of the five external senses, and the functions of the brain, and what will be left behind ? "That life then, or the assemblage of all the functions, is immediately dependent on organization, appears to me, physiologically speaking, as clear as that the presence of the sun above the horizon causes the light of day. "To say that a thing of merely negative qualities, that is, an immaterial substance, which is neither evidenced by any direct testimony, nor by any indirect proof from its effects, does exist, and can think, is quite consistent in those who deny thought to animal structures, where we see it going on every day. " The other class of writers are they who, seeing great design in the structure of animals, and admitting the importance to life of the 13 animal functions, and having daily experience of the influence of physical causes upon the minds of men, do yet upon moral and meta- physical grounds, maintain that some other principle, of which their conception is very im- perfect and their ideas confused, must also exist in union with matter, to explain the phe- nomena of mind, and to render certain tenets in which they believe and fully confide, of possible accomplishment. Now, a future state of existence, considered abstractedly from any physiological or ana- tomical knowledge, is simply a matter of be- lief. Anatomy, considered as a science, is simply a knowledge of animal structure. Phy- siology is simply a knowledge of the uses of the different parts of the body so far as they are ascertained. Hence, they who have only sought, in a knowledge of structure and func- tions, to understand their nature and influence as the basis of practical medicine, have there rested satisfied in their inquiries. While they who, in a belief of a future state of existence, have sought in a knowledge of structure and functions support for such belief, have, after their inquiries, been unable to show from the present state of such knowledge, any support 14 to their creed. On the other hand, some pro- fess to have found in these inquiries, no suffi- cient reason for throwing up their belief. Op- posed in argument, the former have a seeming advantage over the latter, in that they contend only for w^hat they know ; but the extent of their real knowledge is the same, both admit- ting the received anatomical and physiological facts, and neither being able to show any con- nection which they have with future being ; the reasonable assent to another life resting upon other facts than those which anatomy and physiology afford. This being the present state of knowledge, it unfortunately results, that he whose atten- tion and study have been directed to the attain- ment of skill in the cure of diseases, has been driven by the imperfection of science, to the necessity either of regarding animal existence in an entirely physical point of view, or of admitting the existence of some other principle than matter, with which no connection with the organic operations could be discovered. The first admission might be the basis of science to the exclusion of any rational ground for moral principles : the latter might be the basis of moral principle to the exclusion of 15 science. To one of these formidable results, either opinion must lead, unless man could so command his thinking powers, as to regard the same body in two opposite views at the same time. It is not meant by this to deny that many men, eminent in medical and surgical science, and in the practice of piety and moral- ity, have regarded man both as a moral agent and as a physical body ; but they have always been compelled to pursue in argument, oppo- site lines of reasoning, in support of these op- posed notions. And no person has ever traced any satisfactory connection between man as a moral agent, and a physical being. What con- nection has ever been shown between him as a physical being and mind, has a tendency to deny his moral agency, and to make him the creature of physical necessity. These observations, showing the present state of knowledge upon the subject, being pre- mised, I shall proceed to investigate the na- ture of a living animal, and then to inquire into the uses of the different organs and func- tions of the body, and their subserviency to life, in which some new views will be ex- pounded, illustrated, and, I trust, proved. These will enable me, in a later part of this 16 paper, to agitate again and discuss the question of Materialism. Upon a subject admittedly so extensive, complicated, and abstruse, the arrangement of inquiry, the conduct of the argument, the use of terms, and manner of writing, must be stea- dily controlled by simplicity and clearness, to the entire exclusion of figures and ornaments of language ; which, how useful soever they may be in masking error, or in ornamenting subjects requiring exterior decoration, cannot be borne upon the fair person of Truth, without obscuring her form and veiling her beauties. And when it is considered, that in order to investigate this matter with a probability of success, the animal kingdom must be contem- plated in its immense variety, the laws of natural philosophy understood and borne in mind, physiological facts and received opinions considered, arranged, examined, retained, or upon just reason rejected; and that the science of mind, or the knowledge of the intellectual faculties, over which at present there hangs a cloud of great obscurity, must be better ar- ranged and demonstrated : these considera- tions become a fair claim for indulgence as to the method which may be adopted in treating 17 upon this very interesting and important sub- ject. I shall conclude this chapter by observing, that, in the construction of an engine, machine, or apparatus, its parts are made subservient to one great design, and the excellence of its construction depends upon its simplicity and nice adaptation of parts in accomplishing its object. The object to be accomplished is the first consideration with the contriver ; then the peculiar circumstances connected with it; after which, his wisdom is exercised in plan- ning and adapting its several parts. In ex- plaining the nature of an instrument or machine, the natural course is not to expatiate upon its several parts, and then show how the whole is formed, and thence explain the end to be accomplished ; but we must first show the end to be accomplished, then follow the wise design of the contriver in the uses of the more important parts, then proceed to those of less importance, and thence to the minuter pieces influencing its operation in accomplish- ing the object. This course I propose to adopt in treating upon a living animal. CHAPTER II. Metaphysics. — On a faculty and an act — Illustration — Perceptibility is self-evident — Perceptibility and Sensibility not the same — The acts of Perception and Sensation simultaneous but not identical — Illustra- tion — Faculties of retaining, discerning, comj)aring, compounding, and abstracting —- Sameness of the intellectual jjrinciple — Facility ofTFilling — Faculty of Passion a7id Affection. — On the Anima or Soul — The luord Animal an attjective — Soul and Mind have been confounded — Definite Ideas must be form- ed of the tiuo terms — Definition of 3Iind — Our ordi- nary manner of speaking is consistent ivith this defi- nition — On the formation of Mind — Character-^ Definition of Life. THERE exists in every living animal, a principle, power, property, or quality of per- ceiving. And to this principle, power, pro- perty, or quality of perceiving, without here entering into any inquiry as to its mode of being, I shall appropriate the term Percepti- bility. But, that a clear and just notion of the sense in which this term is used by me may be taken, it must be comprehended as imply- ing merely the abstract power or faculty of perceiving, and must not be confounded with 1^ perception, which is the act of perceiving. To avoid being misunderstood, it will be well to have the attention directed to a familiar illus- tration in an analogous power and act. The eye, for instance ; supposing it endued with Perceptibility, might be said to have the power of perceiving the ring of Saturn, but such power could only be demonstrated, when, by the intervention of a powerful telescope, the actual perception of the ring would be accomplished. Or a man, blind from cataract or other cause, may easily be conceived to have the abstract power or capacity of seeing, although actual vision cannot be accomplished, until the obstacle to the exercise of such power be removed. Or a man, shut up in a still dark room, may easily be understood to have the powers of seeing and hearing, although, under those circumstances, he would be incapable of exercising those powers by the acts of seeing and hearing. Perceptibility, consciousness (synonymous terms) or the abstract power of perceiving or knowing, is the peculiar attribute of animals, and is the great distinguishing feature between the animal and vegetable kingdoms. Its ex- c 2 20 istence is self-evident to every living creature ; which evidence, as it is the most certain, so it is the only proof of its existence. While however, the demonstration of this property to every being possessing it is self-evident, the absence of other kind of proof, renders it almost impossible to mark accurately the boundaries of the animal and vegetable kingdoms. Never- theless, as we proceed, there will be found quite sufficient matter to afford the conclusion* that the two kingdoms are perfectly distinct, and that their union has existed only in the imagination of a fanciful philosophy. This term, Perceptibility, must be no longer confounded as it has been, with the word Sensibility : the latter will be found to be an evident quality of matter, admitting of a de- monstration as such, having many of its laws known, and allowing of an increase and dimi- nution of its power from many causes, as will be hereafter shown : it may be defined the quality, power, or capacity in flesh, of convey- ing impressions made upon it, to the perceiving principle. Sensibility implies only the abstract power of doing so, while the term sensation denotes the act. 21 The organic act of conveying impressions to the perceiving power, and the intellectual act of perceiving, being simultaneous, either the term perception or sensation, may therefore be used indifferently, without producing any error in reasoning ; provided they be strictly confined to the acts of perceiving and convey- ing impressions. But the terms perceptibility and sensibility, can never be used indifferently, without leading to the utmost confusion. The vague use of these words has been one great obstacle to the proper understanding of animal life, and the basis of a sophism upon which M. Bichet has founded his erroneous doctrine of vitality — a sophism than which nothing has given a greater support to Materialism. As it is so essentially necessary in the pre- sent Disquisition, to keep a clear and distinct idea of sensibility abstractedly from the power of perceiving, I shall, even at the risk of being tedious, endeavour to render this point, if pos- sible, more plain, by a familiar analogy. Thus, A pays B a sum of money — here are two intelligible acts — the act of payment done by A, and the act of receipt done by B : yet these acts being simultaneous, the mutual act of A and B may be denoted either by the terms 22 Payment or Receipt, without causing any error in reasoning upon the matter : but if A, who pays, be confounded with B, who receives, all right reasoning must be at an end ; their persons not being identical, although their act was mutual and simultaneous. So it is with Sensibility and Perceptibility ; their acts are si- multaneous, but their qualities perfectly distinct. Our knowledge of those operations termed intellectual or mental, is acquired by an at- tention to what passes in our own person, yet the means of communication among mankind are sufficient to prove that similar operations take place in others ; but of the mental opera- tions of other animals than man, very little can be distinctly known. Mr. Locke, in his excellent "Analysis of the Human Understanding," recognises, beside the power of perceiving, the powers of retaining, dis- cerning, comparing, compounding, and of ab- stracting ideas. The existence of these powers in man is universally acknowledged by all who examine the matter; and evidence of this truth may be found by everyone who chooses to direct his attention to the operation of his own facul- ties. These latter powers or faculties are, like per- 23 ceptibility, demonstrable only in their action ; as perceptibility is demonstrated in the act of perception, so the power of retaining is seen only in the act of memory ; comparing, in the act of comparison ; discerning, in the act of judgment ; compounding, in the act of compo- sition; and the power of abstracting, in the mental act of abstraction. Whoever is clearly acquainted with the meaning of these terms— retaining, discerning, comparing, compounding, and abstracting (they who are not may refer to Mr. Locke's book), and has, by a reference to the operations of his own understanding, had proof of the existence of such faculties, must know them to be ex- ercised only upon things previously perceived ; and it is self-evident, that the same principle which perceives is the principle which re- tains, discerns, compares, compounds, and ab- stracts. Animals are also endued with a power or faculty of willing the action or suspension of action of muscles, also of choosing or refusing; and the exercise of this faculty is termed voli- tion. And here it is self-evident, that the same principle which perceives, wills the 24 action or suspension of action, of the muscles, and chooses or refuses. The act of volition is always preceded by perception, and generally, if not always, influenced by the exercise of the faculty of discerning ; this, also, is evident to whomsoever turns his attention to the exercise of volition in his own person. Besides these powers or faculties in animals (but more particularly in man), there exists the abstract capacity for certain feelings termed passions and affections. An enumeration and definition of these feelings individually, would be here tedious and unnecessary. A good account of them may be found in Dr. Cogan*s ** Treatise upon thePassions," byany one desirous of considering them in detail. It is apparent, however, to every one experiencing in his own person, a passion or aff"ection, that such passion or aff'ection is experienced by the same prin- ciple which perceives, retains, compares, and wills. To these abstract powers or capacities in animals (but more particularly in man) of per- ceiving, retaining, discerning, comparing, com- pounding, and abstracting ideas ; of volition ; and of experiencing passions and affections ; to 25 these powers, qualities, or capacities, taken in the aggregate, without here entering into the inquiry as to their mode of existence, may be appropriated the term Anima or Soul ; and any, or every one of these powers or capacities, considered individually, may be called a faculty of the soul. There is derived from the substantive Anima, the adjective word ' animal,' which is a good expressive of the quality of its original. But, from some strange perversion, this derived term has been made to usurp the place of its original — has been made substantive — has had plural termination — and by long- continued abuse has become in meaning, just the reverse of its original signification ; the terms ' animal grati- fication,' being now used to denote strongly an opposite to 'intellectual or mental enjoy- ment,' although the real meaning of these terms is exactly the same. For the purpose of keep- ing a clear understanding upon the present subject, this misuse of the term ' animal' must be reformed, or at the least it will be desirable to consider the term always adjective and ex- pressive of quality, and to understand the word * being,' in connexion with it. In the Mosaic account of the creation, admittedly the only 26 one having any claim to authority, the word * animal' is never used, nor any word which can be considered synonymous with it : but when the living creation is spoken of, it is generally by a detail of its several kinds; as *'man, the beasts of the field, the fowls of the air, the fishes of the sea, and all creeping things that creep ;'^ or, where reference is made to them all collectively, it is under the terms "every living thing." And throughout the whole of the Jewish Scriptures, neither the word 'animal,' nor any corresponding term, is ever used ; nor is it to be found in the more recent Scriptures of Christians — the New Testament. The great argument in favour of the doctrine of Materialism, and that which is most dwelt upon by its supporters, is the fact of mental development accompanying the organic deve- lopment of the body. This fact is invulnerable to the attacks of its opponents ; and, viewed in any point, it presents the impenetrable armour of Truth. For, as has been before observed in quotation, not only is organic development essential to the formation of the mind, but or- ganic derangement may occasion mental de- rangement ; suspension of organic operations may suspend mental operations, as is seen in fainting ; and high organic excitement evinces frequently great mental display ; besides these, the decay of the body is generally accompanied by impaired mind ; and the destruction of the organized body is, to all appearance, the death- blow of the mind. Much of the unprofitable controversy upon this subject, and the many difficulties in which it is involved, appear to me to have arisen from a vague and unsettled application of the term ' Mind,' which has sometimes been used to signify the soul, sometimes the ideas acquired by the soul, sometimes an opinion, and some- times a desire or wish. No writer upon this subject appears to have taken any definite views of the two terms soul and mind, and hence they have been used in so ambiguous a sense, as to render nugatory any attempt to establish just opinions upon the nature of animal being. Hence, also, the discourses of philosophers, divine and profane, teem with such irreconcilable positions, as seldom fail to render the subjects connected with this matter, a mere mass of bewildering words. Even Mr. Locke, whose acuteness in discerning, and powers of analysis were admittedly so great, has used these terms without any definite 28 meaning, by which his subject (the human understanding) has suffered much obscurity, and his opinions been laid open to much unne- cessary debate. To obviate and guard against the confusion which must otherwise arise, I shall here, however arbitrary the distinction may appear, give a definition of the term * Mind* in contradistinction to the Soul ; and the just, nessof it, as well as its utility, will I trust appear in the sequel. The Mind is constituted of those ideas and that collective knowledge, which the anima or soul of an individual may have acquired through the medium of the organs of sense, and by its own powers of retaining, comparing, discerning, compounding, and abstracting ideas. Also, of that aptitude or readiness which the soul of an individual may have acquired, of willing the action or suspension of action, of muscles, and of choosing and refusing. Also, of that aptitude or readiness for certain feelings, with their accompanying actions, called passions, or affec- tions : or, in fewer words, it may be defined the acquirements of the soul. Hence it should appear, that the faculties of the soul may be inherent, while the Mind of the animal is evidently and admittedly acquired. 29 Mankind, without having clear and definite ideas upon a subject, do yet sometimes have such a glimpse of the truth, as preserves them from falling into gross inconsistencies of speech. Of this, an example presents itself in the com- mon usage of the term * Mind,' v^^hich, how muchsoever it may have been abused in philo- sophical disputes, has been correctly appro- priated in common parlance. Whence these expressions are of daily occurrence, an imbecile mind, deranged mind, enlarged mind, enervated mind, decay of mind ; and the formation of mind, is spoken of in children. But the expres- sions of imbecile soul, deranged soul, enlarged soul, decay of soul, do seldom or never occur ; nor is the formation of soul ever spoken of in children. The expressions enlarged mind, and enlarged soul, if compared, will be found to convey different ideas ; the former will be under- stood to be an acquirement of knowledge, the latter, a soul liberated from the body ; at least I conceive such would be their acceptance, if not used in a connected discourse. Like every complex subject, the Mind also, to be properly comprehended and understood, must be contemplated in its several parts ; and this cannot be done better, than by observing 30 its gradual and regular formation in young animals (more particularly in man). For this purpose, turning the attention to the mental development of the infant, we perceive it gradually acquiring ideas through its organs of the senses, also acquiring gradually a command over certain of its muscles, v^hich, w^hen reduced to the dictates of the will, are called voluntary muscles : these two acquirements constitute the first stage of mental develop- ment. Brute animals appear to acquire a much more immediate and decided command over their muscles of loco-motion than man, the reason of which circumstance will be rendered intelligible hereafter in treating of muscular motion. An immediate command over the muscles of deglutition is common to all. The next stage may be considered that in which the infant slightly retains, compares, and discerns ; and the voluntary muscles are used in connection with some desire ; its passions and affections, also, now begin to display themselves in unguided caprice. At a later period, when the organs of the senses and of voluntary motion, are perfected in their functions and connection with the perceptive and willing power^-of the animal, it is seen compounding .its i^^^VL wy and improbable visions anji 31 fancies ; there is also seen a kind of compound- ing of animal movement in unison with the sensible perception of sound, in dancing : and there occurs now, a natural desire and inclina- tion to form and indulge in an unrestrained combination of ideas with objects of the will, passions, and affections : this is the unsettled age of romance, imagination, desire, passion, and affection ; the giddy, blundering, fluttering, mad, happy, despairing, merry, sad, trifling day of youth, which soon passes and is gone. The higher of the intellectual or reasoning faculties now becomes exercised — abstracting, which is the basis of analytic inquiry, the foundation-stone of science, and the ennobling rock of man's intellectual superiority. This period, adolescence, is the spring time of reason. The already-acquired parrot-like knowledge of languages, the imagined person- ality of God, the gross knowledge of sensible objects, ideas of justice, morality, vice, &c., now become the objects of inquiry on the basis of abstracting, and the laws of science may now be comprehended and retained. From this period, the minds of men become much diversi- fied, and the intellectual faculties, having been well or ill directed and exercised, and the passions and affections having been properly 32 regulated or indulged in unbounded licence, give, as the result, that immense variety of Mind which is only equalled by multitude of animal form. This separate consideration of Soul and Mind is only necessary in a philosophical investiga- tion of animal being : in the ordinary affairs of the world, the faculties of the soul, with its acquired knowledge, habits, and actions, are considered collectively with the corporeal frame in the idea of individual character. Thus the faculties of the soul having been exercised in the contemplation of the laws of numbers and measurement, afford the character of the mathematician ; in the science of sounds, as forming harmony and melody, the musician ; in acquiring a knowledge of the laws of natural bodies, the chemist; in the contemplation, admiration, and reverence of the Supreme, the pious man ; exercised in those acts considered virtuous, the virtuous character ; in those con- sidered wicked, the wicked character; exercised in acquiring a peculiar command over the voluntary muscles, the dancer, fencer, volteur, &c. ; in conceiving correctly, and acquiring the act of representation or imitation, the actor and mimic ; correctly exercised in the investi- 33 gation of truth, the philosopher : but it is tedious to enumerate the simple definitions of partial character, and extremely difficult to accomplish a general description of the com- plicated character of any individual. This latter object should be the aim of the biographer, and should embrace person, natural and acquired, bodily and mental powers, habits, knowledge, opinions, arts, passions, and affections. The existence of the faculties of the soul, as enumerated in the preceding pages, must be, and is admitted by all, whether Materialists or not ; the question at issue being only whether they be qualities of matter arising from peculiar organization, or whether they have a separate and independent existence. The existence of such faculties being admitted, and also the brain, or, as some contend, the brain and spinal marrow, being the acknowledged seat of such faculties, I now^ proceed to the definition of life. Than this, nothing has hitherto been more difficult, nor is it matter of surprise when it is considered, that the just definition of any subject or thing depends upon a correct know- ledge of it, and is a conclusion rather than a first principle of reasoning. The usual defini- 34 tion of life is, that " it is the sum total of its functions." This definition, whatever know- ledge it at first appears to convey, is a mere waiving of the matter, as it may be asserted of every thing or being that it is the sum total of its qualities. My definition of life, a conclusion founded upon physiological opinions hereafter to be advanced, and to be maintained upon grounds hereafter to be jealously and suspici- ously scrutinized, is, that it is a relation between an anima or soul, and the natural laws of this material world. And the proper understanding of the mode in which this relation is accom- plished, with a knowledge of the uses of the difierent parts of the body in efi'ecting this, constitutes the science called Physiology, a most important, and in practical medicine, the most useful, branch of the science of life. This definition may be objected to, on the ground that it is too limited for the long-accepted use of the term life ; it having been many years used to indicate, not only the life as here defined, but also the organic operations by which that vital state is accomplished. But to identify those operations with life, and to speak of a living head of a decapitated ox, because its muscles keep moving, or of a living corpse because the beard grows, is too glaring 35 an abuse of terms to be dwelt upon. As well might one be required to make a definition meet the sailor's abuse of the term when he uses that common phrase " no ship can live in such a sea," as to meet this abuse of a false philosophy. The functions of life are as distinct from life itself, as the powers of movement are distinct from motion. I have thought it neces- sary to be thus diffuse upon the idea of life, because the scientific phraseology of the day has, in the universal use of the terms * organic life,' arbitrarily but erroneously given the notion of two lives in an animal. This life, or relation between an anima and the material world, is effected by the mediate agency of the structure and functions of the body, from which results that property of living flesh called sensibility, of which I shall now proceed to speak. In the investigation of this property, the accomplishment and support of which appears the first grand design of God in the formation of animal bodies, and the object to which their functions chiefly tend, a range of inquiry and discussion will be neces- sary more extensive than may be anticipated, and it ^vill be found to embrace nearly the whole science of Physiology. D 2 CHAPTER III. Atiimal sensibility — its modifications Jive — the organs of the Jive modifications — arteries and nerves essen- tial to sensibility — on the arteries — on the nerves — connecting observations — Proposition — Facts in support — an essential preliininary cotisideration — Sum or force of a Sensation is determined by three circumstances — enumerated— Jrst circumstance con- sidered — second circumstance considered — third cir- cumstance considered — Conclusion concerning these three circumstances — Several animal phe7iomena explained — Conclusion. ANIMAL sensibility is that property in living flesh by which the anima or soul is brought into a relation, or within the influence of the laws of the physical or material world. Or, in other words, it is that property by which impressions made upon the part endued with it, are transmitted to the perceiving power of the animal. To this definition of sensibility I will, to avoid a possible error, annex again the definition of perceptibility, and also of the terms denoting the exercise of these two powers. Perceptibility is the power of perceiving. Per- ception is the act of perceiving. Sensibility is 37 the power of conveying impressions to the soul. Sensation is the act of conveying im- pressions to the soul. From the circumstance of the act of sensation and the act of perception being simultaneous, these terms have been used indifferently to denote the effect of physical causes acting through the body upon the soul : but, although in ordinary discourse the terms have the same meaning, yet in this philosophical investigation, the distinction must never be lost sight of, otherwise the understanding may arrive at a most palpable error in the result. All sensible parts are not susceptible of the same physical causes which excite sensation so as to convey their influence to the perceiving- power of the animal ; but the different suscep- tibilities to physical causes have been divided into the organs of touch, sight, hearing, smell and taste. These are all modifications of the same property, and are equally embraced in the after-reasoning upon its nature. In man, and all those animals whose size admits of structural and functional inquiry, anatomy, observation and experiment teach, that every part possessing sensibility is sup- plied with arteries and nerves, and that upon 38 their functions this property is dependent. It has been reasonably enforced by Sir C. Morgan, that in an individual having a nervous and a blood-vessel system, the slightest puncture w^ith a needle will cause pain, and draw blood ; and these effects he considers conclusive of the fact, that such part must be endued with nerves and blood-vessels, altliough they may not be discoverable by the eye and the scalpel. To me it appears equally conclusive, that any animal in which a puncture will excite pain and draw blood (it may not of necessity be red) must be endued with these two systems. I therefore infer, that every animal has a nervous and blood-vessel system, whether they may have been seen by the naturalist or not. Arteries are elastic tubes originating from the heart, and ramifying throughout the whole animal structure, conveying a fluid, red in man and many animals, termed blood. The exact manner of their termination is a matter of dispute. That fluid, however, is returned to the heart by another set of tubes termed veins ; whence it is again circulated. This is the most simple idea of animal circulation, in which it is considered independent of its connection with the lungs. The great difference between 39 vegetable and animal circulation is, in the former consisting of a slow and gradual diffusion of its fluid throughoLit the vegetable body, while that of the animal is a rapid, impetuous, and beating torrent. Nerves are long white medullary chords, communicating with the brain and the spinal marrow, and distributed, as was before observed, to all parts endued with sensibility. They have long been considered the immediate organs of sense ; and the simple fact of a division of nerve, or pressure upon it, interrupting sensation, may serve for proof of their office being essential to that act. But it is equally true, that any interruption to the sanguiferous circulation, either by division of the pulsatory organ (the artery) or by sufficient pressure to prevent its flow and beating action, will equally prevent the act of sensation. It is therefore in their combined action, that an explanation of this property of the animal is to be sought. The exact nature of the operation which takes place between these two systems, now becomes a subject of inquiry, interesting in itself, and highly important in leading to correct views of the functions or uses of other organs of the 40 body. On a subject like the present, it would have been desirable that all the positions should have immediate proof, by direct appeal to evidence, or have been the logical result of previous reasoning : but, in the present instance, Mfhere the subject is so complicated and abstruse, the object both of the writer and of the reader may be much facilitated, by advancing a Pro- position, and giving, after directing the attention to some peculiar circumstances connected with life, the proofs of its truth. The writer will thus, without any sacrifice of truth, or departure from the just principles of logic, attain a more easy method ; and, by at once putting before the reader the object to which a consideration of these cir- cumstances and the after-reasoning tends, those imperfect anticipations and surmises of the author's aim, which cannot fail to distract the attention from the force of the argument, if otherwise conducted, will be prevented. Proposition. — In parts endued with sensibility, the nerves are pervaded by electric fluid, and the circulating blood does excite to action this fluid at the extremities of the nerves, and there- by occasions an electric vibration throughout their whole course, up to that part of the brain or spinal marrow in which is seated the per- 41 ceiving power. Such a state constitutes sensibility, for any further impression falling upon the part, occasions a sufficient further motion to impress upon the perceptibility of the animal a sensitive idea. It is to be under- stood, that the nerves are conductors of vibra- tions, and not that they do actually vibrate themselves. In support, it is to be observed, that experi- ment proves the nerves to be conductors of electricity, and they are enveloped in a con- densed membranous coat, which is a non- conductor of electricity; so far the natural arrangement appears conformable to the pro- posed truth. The next question which naturally arises is, whether an electric shock be capable of producing that variety of sensation which the animal is capable of experiencing. Here the proposition has the required support, since an electric shock passed through the skin, gives the sensation of an impression of contact, through the eye of light, through the ear of sound, through the tongue of taste, and through the nostril of smell. In observing upon the proper and natural method of explaining the uses of a machine, it 42 was said, that, after pointing out the end to be accomplished, it was necessary to take into consideration the circumstances connected with its operation. This must now be done with regard to a living animal. It must be admitted, that the heat of the atmosphere, light of the sun, and sounds con- veyed by the air, and that savours and odours are determined by fixed general laws, and this fact is clearly demonstrated in the knowledge of natural philosophy. Wherefore, there must appear a necessity that all animals under their influence should perceive through organs of somewhat similar powers : for had things been perceived through organs of dissimilar powers, there must have prevailed a strange confusion of perception among animals, upon the intensity of any given degree of heat, light, sound, taste, or odour ; all general estimation by the senses must have been widely discordant, instead of that trifling difference which at present exists ; and no just notion of any sensitive idea could have been communicated among mankind, which is the basis of all mutual reasoning. Had animals perceived through organs of dissimilar powers, the light of the sun must have been intolerably luminous to some, and utter dark- 43 ness to others : the heat of the atmosphere must have produced insufterable burning, or have been intensely cold to the majority : while the vibrations of air, which give rise to sounds, must have produced the most astounding effect, or have been insufficient to have excited the necessary impression upon the perceptibility of the animal : out of myriads of sensitive beings, few, indeed, would have been the number of those to whom the laws of the natural world would have been a source of pleasure and safety, or in M'hom they would have admitted of a con- tinuance of life; while a diversity of perception from the same causes, would have precluded the use of a common language and mutual reasoning among mankind, by the impossibility of fixing definite perceptions or ideas, with particular words. The assertion, that all animals must perceive through similar powers, is not meant to imply that every living animal must be endued with feeling, sight, hearing, smell, and taste ; but that, in possessing any one of those powers, it must have an adaptation of its organ or organs, to the natural laws by which its corresponding act is excited. 44 Now, in order to comprehend how this similar power is constituted in the organs through which animals perceive, it will be necessary to consider the circumstances by which the sum or force of a sensation is deter- mined ; and these circumstances will be in part grounds for proof of the proposition advanced upon the nature of the operation which takes place between the arterial and nervous systems. The sum or force of a sensation, I shall be able to shew, is determined by three circum- stances, viz., by the force of the cause pro- ducing it — by the degree of sensibility in the part receiving the impression — and by the extent of sensible surface exposed to the action of the exciting cause. The causes excithig sensation are light, heat, vibrations of air, peculiar principles emit- ted from vegetable and other substances, termed savours and odours, and the direct contact of bodies. The whole animal creation is under the influence of some or all of these causes, and the various degrees in which they are perceived by the individual, make the amount of its sensitive knowledge or ideas. These natural causes are to be considered the first circum- 45 stances influencing the sum or force of a sen- sation. That the sum or force of a sensationis p artly determined by the degree of sensibility in the part receiving the impression, may be readily shown, by adverting to inflammation ; in that disease, sensibility becomes preternaturally acute, and the affected part is no longer capable of bearing with ease, the same impressions to which it had been previously accustomed. If the disease be situated in the eye, there will be intolerance of light ; if in the ear, of sound ; and the contact of bodies on other parts cannot be borne with the usual ease. While, on the contrary, in parts which have their sensibility diminished by bleeding, discharges, or other causes that weaken or interrupt the action of the circulation, sensation can only be excited by stimuli more powerful than are naturally requisite. Hence the degree of sensibility in a part, is a second circumstance determining the sum or force of a sensation. That the extent of sensible surface exposed to the action of the exciting cause, partly determines the sum or force of a sensation, is remarkably shown in considering the function 40 of the iris ; the painful sensation experienced from a great quantum of light admitted upon a large portion of the retina during the dilatation of the pupil, is removed, and ease and perfect vision restored, by its (the pupil's) contraction, because of the smaller surface that is then excited. In diseases attended with a languid circulation, and where the general sensibility of the body is consequently diminished, a dilatation of the pupil is naturally an accom- panying symptom, because, if a larger surface were not exposed under this change of sensi- bility, vision could not have been effected by the ordinary light: on the contrary, in diseases attended with a general increase of sensibility, the pupil is contracted, because, under this change, vision would have been extremely painful if the same extent of surface had been exposed, which is necessary under ordinary circumstances. Animals can likewise bear a degree of heat upon a small surface of their bodies, which, if applied to a larger, would produce considerable pain ; this may be proved by experiment with hot water, by immersing a small part of an extremity, as a hand or foot, in water heated to the most tolerable point, if the whole extremity be then plunged into this heated water, a painful or intolerable sensation 47 will be excited. In smelling and tasting, "also, we apply savours and odours to a larger surface of our organs, when they do not excite suffi- ciently by their ordinary application. These examples are sufficient to show the influence which extent of sensible surface has, in deter- mining the svim or force of a sensation. Here the attention may be directed to the circumstance, that where the natural causes producing sensations are fixed, or but little subject to vary in their degree, a determinate degree of sensibility simply is sufficient ; but where the causes of sensation are subject to considerable changes, and to be applied under modified circumstances, there, an apparatus, acting as a regulator, is necessary for the pur- poses of the animal. The density of bodies, as influencing the sense of touch, remains the same ; and the thermometrical range of heat, capable of being distinguished by sensation, is inconsiderable; to those causes, therefore, a determinate degree of sensibility simply is sufficient. Animals could not be sensibly affected by a much greater thermometrical range of heat, because, by the one extreme, the organic operations of the body are sus- pended ; and, by the other, destroyed ; namely. 48 by intense cold and fire. Fixed degrees of sensibility simply, are also sufficient for the purposes of smelling and tasting. But there occur immense variations in the degree of light ; yet, by the eye, through the regulating function of the iris, which, by exposing a larger or smaller surface of the retina, keeps the power of that organ (the eye) nearly the same ; under the great range from twilight to the most glaring degree of luminous influence, bodies are clearly perceived, and without pain to the animal. Also, the changes in the degree of sound, arising from the ever-varying density of the air, are much obviated in their effects, by the muscles connected with the tympanum having a regulating function upon that organ. The three circumstances enumerated, deter- mining together the sum or force of a sensa- tion, and there being an evident necessity that all animals inhabiting the same world and sub- jected to the same fixed physical laws, should perceive through similar powers, there becomes an apparent necessity for an increase of sensi- bility to accompany the diminution in the size of animals, from man downwards ; and a diminution of sensibility from him upwards, in order to bring all within the due influence 4d of the physical laws of the world, relative to heat, light, sound, &c. If animals had not possessed such variations in the degree of their respective sensibilities, it must be quite evident, that that light which would have been sufficient to excite vision in man, would have been insufficient to excite it in the smaller eye of the lesser animals; while the larger eye of the greater animals, would have been sub- jected to an immense glare. The ordinary warmth of the atmosphere, if of comfortable endurance to man and animals of his size, would have been intolerable heat to the very large animals, and absolute coldness to the smaller ones, if the degree of sensibility had been the same in all. Similar reasoning is applicable to the senses of hearing, smelling, and tasting. This increase of sensibility in the smaller animals, and decrease in the larger, then, give nearly similar powers to the whole animal creation, and bring all within the due influence of those laws, by which sensations are excited. Those animals, who see in what man terms the dark, or whose organs of hear- ing or smell are very acute, do not militate against the foregoing argument ; their powers of sight, hearing, and smell, being adapted to the natural laws of light, sound, and odour ; 50 although, from the greater sensibility of their organs, they are rather sooner affected by those causes than other animals. The importance of different degrees of sen- sibility to animals of different size, and the indispensable necessity that each animal should have its appropriate degree to accomplish its suitable relation with the laws of the physical world, must now be sufficiently apparent. Whether this degree of sensibility be deter- mined by the force and frequency of the pulsa- tory circulation, or whether the force and frequency of the pulsatory circulation, be an effect of the electrical operations by which sensibility is accomplished, may be a subject of some doubt ; but, in either case, the force and frequency of arterial action are always correspondent with the degree of sensibility, so that they may at all times be considered the indication, if not the cause, of the degree of sensibility. Hence, we may understand why any unnatural increase or diminution of arterial action is accompanied by a destruction of that just relation, between the perceiving power of the animal and the laws of the material world, on which life and health are dependent. Where an unnatural increase of pulsatory circulation 41 occurs, the sensibility not only becomes in^ creased, but the very action of the pulsating artery is conveyed by sensation, to the per- ceiving power, and constitutes the throbbing of inflammation. The irregular supplies of food to the greater part of the animal creation, but more particularly to that which is depend- ent upon prey, must occasion great variations in the quantity of circulating fluid ; yet this is not attended by any material change in the sensibility of the animal, because there is made up in frequency of circulation, what is lost in fulness of pulse : hence the pulse of the starv- ing man is always extremely small and quick, and nothing but food will check its action. Persons suffering under diseases of exhaustion, have also this small and quick pulse. Bleed- ing, in health, invariably increases the quick- jiess of pulse, but it is not perceivable until the natural degree of sensibility is restored ; which, during the operation, is generally much diminished. It must also be evident, from the foregoing reasoning, that the infant, partaking of the nature of the smaller animals, has occa- sion for a greater degree of sensibility than the adult ; this is accompanied by a more rapid circulation, and thence the frequency of the ioiantile pulse, and not as has been represented 52 by M. Bichat, from any superabundance of life. Hence, also, it is, that the circulation in small men is more active than in large ; and the pulse of woman, from her smaller size, is generally quicker than of man. If this fre- quency of pulse in the infant were, as M. Bichat has represented, from a superabundance of life, a reduction of it might be safely effected ; but if the experiment be made by reducing it to the frequency of an adult pulse, the in- fant's sensibility will be so much reduced, as to destroy totally its connection with the laws of the material world ; or, in other words, it will cease to live. On the contrary, if we attempt to force the circulation of large ani- mals to the frequency of the smaller, we so completely alter their sensibility, as to unfit them for a proper estimation of the force of the natural causes to which they have been accus- tomed ; and hence, they neither feel nor act in their usual manner, but present those states known as drunkenness, delirium, or madness. There is a simplicity, beauty, and import- ance, in all the known laws of Nature, so far as they have been ascertained by philosophy, which would lead us to expect the same in the economy and structure of animals. But, in the 53 present received notions of life, there is found an useless complexity and a series of encum- bering operations, quite at variance with the nice adaptation of means to an end, and by which, according to present received notions, the animal is continually endangered, without any adequate utility. In treating of these operations in connection with this subject, the path to which is now rendered easy and plea- sant, it will appear, that where mankind have taken up notions at variance with great sim- plicity and nicety of design, such notions are without rational support, and are opposed by almost every circumstance connected with the opinion, as will appear as we proceed. Several of the following chapters, although the Disquisition be conducted under different heads, have an intimate connection with the present subject — Sensibility ; and proofs of the proposition advanced in this chapter, will be continued through those which follow. CHAPTER IV. Assimilating organs — the uses of food- taking — > decomposition of the body questioned^-The pre- servative j^rinciple of Jlesh, or 3Ir. Hunter's vital principle — mai/ be exhausted — and again restored — TVhat this jirinciple is—Wlie7ice derived— Facts in support — On the required quantities of food — Con- clusio7i. THERE is in every living creature an ex- tensive and important series of operations, of which a lengthened description and detailed consideration will be here unnecessary. In these operations, a considerable portion of animal structure, comprising a large assemblage of organs, is employed ; and they consequently become a matter of inquiry in connection with the present subject. These operations, com- prising digestion, nutrition, and their concomi- tant functions, when regarded collectively, are usually called the functions of assimilation; which terms, although they do not exactly meet my views of the ultimate uses of those operations, may be retained for the present. It is sufficiently reasonable to admit, that the functions of assimilation may be for the purpose 55 of advancing the growth of the body ; but why these functions should continue after the animal has attained its full size, requires a better ex- planation than the universally assumed, yet unsupported, notion, that there is a continual wearing away of animal structure. This opin- ion of the continual decomposition of the body, although universally received and admitted, appears to have arisen solely from the circum- stance of animals when at full growth, still requiring considerable supplies of food ; and for what purpose, physiologists were at a loss to conceive, unless they previously admitted such decomposition. Upon the assumption of the continually de- caying nature of the body, men have gone so far as to calculate the time during which the whole structure is changed ; although, I be- lieve, they have never determined among them- selves any exact period which has gained general assent ; but the opinion is left varying between the space of four and twelve years. Upon this assumption, also, a great deal of the argument between Mr. Locke and the bishop of Worcester, concerning personal identity, turns. Yet, although experiment with madder has shown that great changes take place in 56 the body (which I conceive are chiefly confined to the fatty deposit of the cellular structure, and to the fluids), I am not aware of, nor can I ascertain, any facts which tend to show — what has been so readily acceded to by phy- siologists—that in health, a lamina of bone is removed and another substituted, and that the fibres of a muscle are taken away by absorption, and others arranged by the nutritive process, and that the structure of arteries, veins, nerves, &c., are decomposed, and others formed. If such great revolutions were continually taking place, surely a much greater obliteration of the marks of injuries would occur than presents on the examination of dead bodies. The experi- ment with madder is no more proof of the decomposition of the body, than a piece of flannel dyed red and immersed in some current of fluid until it had lost its colour, would be a proof of the decomposition and re-formation of such flannel. But here, as in other instances, instead of pursuing further the objections to this notion, time will be saved, and it will perhaps be better combated, by proposing and supporting, by appeal to facts, another opinion more in unison with the known simplicity observed in nature, and in better accordance with the great object of animal life. 67 One of the most striking phenomena of living bodies, particularly noticed by Mr. Hunter, is their property of withstanding those common laws of matter called chemical affinities. This property is intimately connected with sensi- bility, as is seen by a loss of sensibility always preceding a chemical decomposition of animal substance. When these chemical changes take place in a part of a living animal, it is called gangrene, or mortification, and a restora- tion to its former structure is never accom- plished : new flesh may form, but the original substance is converted into chemical elements, and thrown off from the body. There does, however, sometimes occur a general tendency to these changes, where the fluids of the body appear chiefly affected by it ; and when such a state results from fever, it is called putrid fever. Here, with great prostration of strength, and much diminished sensibility, the secretions in the mouth and in the whole alimentary canal, become extremely offensive ; the ex- cretions all partake of this approach to putre- faction, and even the whole mass of blood is involved in this approach to general destruc- tion. Exactly the same symptoms, but arising from another cause than fever, constitutes the disease known by the terms sea-scurvy. Yet, under proper treatment, and favorable circum- stances, it frequently happens, that these chemi- cal laws of affinity become again suspended, and the natural healthy laws of the animal again restored ; the fluids regain their pristine sweet- ness, the sensibility its proper standard, and a complete restoration of animal strength and power is the result. There must, therefore, unquestionably exist in animals a power of generating some principle by which the che- mical laws of matter are subverted, and this principle is electric fluid, by the agency of which I have assumed sensibility to be effected. And this fluid (the electric) is elaborated from the received food, by the action of that series of organs which have hitherto been regarded as labouring only for the re-building of a continually mouldering structure. In support of this opinion, I may observe, that I have never seen a single instance of general putrescency where the assimilative functions have been tolerably natural, except where the food has been of defective quality. And a return of appetite has been the period from which I have always prognosticated with certainty, a cessation of the putrefactive process, and a return to animal combinations, in 59 those instances where putrescency has greatly prevailed. If digestion, and all those processes embraced in the notion of the assimilative functions, were not for the purpose I have assumed, but merely for the rebuilding of a continually decaying body, the relative supply of food required, should have accorded with the relative size of the animal : but this is not the case, for the smaller animals consume much greater relative quantities of food than the larger. The voracity of children is proverbial ; the difference in the quantity of food consumed by small and large men is imperceptible ; the larger animals are temperate ; while the smaller are by natural necessity voracious. These differences in the required relative supplies of food, may not perhaps be apparent, unless the attention be carried to, and observation made upon, the very large and small animals. The very small animals are then seen to consume daily a quantity of food equal, and oftentimes surpassing, their own bulk ; while the larger ones require several weeks to consume a quantity equal to their bulk. In proof, compare the relative quantities of food consumed by the elephant, camel, &c., with those consumed by wasps, beetles, flies, &c. Or taking two animals who feed upon the same food, observe the com- 00 parative quantities consumed by the rabbit and the horse ; the former soon consumes a quantity equal to its own bulk, but a quantity equal to the bulk of the horse would not be consumed by him in several weeks. An animal that is not kept in relation with the laws of the material world, by the combined action of its arterial and nervous system, may remain months with- out food, without undergoing a chemical decom- position, as may be observed in the dormouse, and other hybernating animals ; and, for a much longer period, as has beenknown of flies, which have remained torpid for years. On the contrary, animals who are excited to a preternatural vigilance, require unusual quantities of food. The required supply of food then does not correspond with the size of the animal, but is increased in the smaller, and decreased in the larger : sensibility has also been shown to be necessarily increased in the smaller, and decreased in the larger, animals : from these circumstances, and the facts of torpid animals living without food, while those who are pre- ternaturally excited, require unusual quantities, I am led to conclude, that the required quantity of food corresponds very much (although as I shall hereafter show, not altogether) with the required degree of sensibility, and hence, that 61 the ultimate use of the assimilative organs and food-taking is, the supply of electric fluid, upon the agency of which I have assumed sensibility to be dependent. This view of the ultimate uses of the assimi- lative organs will be further borne out in a more extended consideration of animal exist- ence, for which we shall hereafter be better prepared, by an advanced examination of the circumstances connected with life in the next part of our inquiry, as well as by a considera- tion of the nature of some diseases to be spoken of in a later part of this paper. CHAPTER V. The Limgs^hring the blood into contact with the air —supposed object of this— questioned— and disj^roved —Animal heat— no Jixed degree essential to life — the degree of heat an adventitious circumstance — source of heat and use of the Lungs— argument in support — 071 media influencing the degree of heat — Fishes — Amphibia — Insects — Conclusion . SITUATED in, and nearly filling, the chest, (in man) are some fleshy sponge-like bodies, very permeable to air and exceedingly vascular, called Lungs. The evident design of these bodies, apparent both from their structure and function, is to bring into contact with the surrounding medium a large surface of the circulated blood. Of the exact chemical combinations and results thus effected, there is but little agreement among experimenters, scarcely any two in- quirers having come to the same conclusion. These organs, however, are of such considerable importance in the animal economy, and, unfor- tunately in this country, so frequently the seat of destructive disease, that they claim on both accounts a deep interest and a cautious con- sideration. Without, therefore, entering mto a tedious discussion of the chemical affinities there exercised, or considering their secondary- uses in the exercise of the voice, I shall proceed to investigate and treat of their primary use and importance as subservient to life. Their use has long been considered in connection with animal heat, and the most prevailing and commonly-received opinion is that proposed by the ingenious Dr. Crawford, founded upon Dr. Black's Theory of Latent Heat. He assumes, that arterial and venous blood have different capacities for caloric, and that the capacity is least in venous blood, and hence, that heat becomes sensible in that state ; then, as a quantity of heat is continually given out from the body, the blood passes through the lungs in order to receive from the air materials for a further combustion, and the principle, thought to be received for that purpose, is oxygen. This theory, notwithstanding the supposed analogy between breathing and combustion, which has been so much dwelt upon by its supporters, is opposed by so many facts, requires so many unsupported assumptions, and is so at variance with nearly all the phenomena of disease, that 64 it cannot have been received from any convic- tion it carries with it, nor from any tendency which it has to clear up the mysteries of life. For, although Dr. Black has shown, and it may be clearly comprehended, that bodies have different capacities for caloric, yet it has never been supposed that their capacities are changed by mere change of situation ; and it requires some stretch of the imagination to suppose that blood in an artery, and the same blood in a vein has different capacities for heat. But its fallacy cannot be doubted, when it is reflected, that heat is given out in an incubated egg, in which case there is no constant supply of oxygen ; and that, in cases where persons die from an insufficient supply of oxygen, as in those who breathe the gases from lime-kilns and charcoal, the heat of the body becomes much increased previous to death; and, if oxygen be here timely supplied, the heat diminishes and the patient recovers. In extensive inflammation, a much greater quantum of heat is evolved than in health, although the action of the lungs be not increased. Another, the most important objection to this theory is, that in pulmonary consumption, where the lungs become much wasted, the heat of the body, instead of being diminished, as it must have been if such theory had been true. 65 becomes increased, and the system can only be relieved of its superabundant caloric, by fre- quent and profuse perspiration. Some have supposed, and among the number Baron Cuvier, that the lungs are in proportion to muscular development. To this an objection presents in the fact that the largest-lunged dog (perhaps quadruped) is the grey-hound, who certainly is not the most muscular of that species. This animal also presents an insuperable oppo- sition to the lungs being for the purpose of supporting animal heat, because in his large- lunged existence is found one of the most chilly animals of the dog-tribe. Numerous as have been the experiments instituted for the purpose of determining the chemical changes which take place in the lungs, and multiform as have been the results of the inquiries, but little has been established so as to gain a general assent. It has been how- ever shewn, from experiment, that the same chemical changes which take place in the lungs occur on the skin ; it is therefore highly probable that the lungs have merely an ex- tended function of the skin, and there is no more reason to conclude that they are for 66 generating heat, than that tjiie Sikin feas a func- tion for that purpose. On a general survey of the living creation, it has been observed, that the natural temperature is much varied ; and writers upon this subject have remarked, that those animals vv^ho do not breathe have a temperature very little higher than the medium in which they live, while man, and those animals who do breathe, have a temperature considerably higher than the atmosphere, and that birds, who breathe in a still greater degree, have even a higher tempe- rature than man and quadrupeds. These cir- cumstances have been considered the strongest proofs of the utility of the lungs in supporting animal heat. The establishment of truth being the best refutation of error, I shall, instead of shewing here the objections to this opinion, proceed at once to explain the source of heat in a living animal, and shall submit those cir- cumstances which are opposed to the present prevailing theory, as they may arise. There is no particular temperature which can be said to be essential to life, because it is seen so much varied throughout the series of living beings. The natural temperature should there- 67 fore be considered an adventitious circumstance, and an explanation sought as such. The facts, that heat is not given out if the action of the arteries be suspended — that pressure upon a nerve is attended with coldness of the part supplied by it — and that any unnatural increase of circulation, whether local or general, is attended by a corresponding increase of tem- perature — are circumstances which support the opinion of the source of heat being in that operation between the arterial and nervous systems, from which the sensibility of animals results ; while the fact of heat being given out in considerable quantities from the lungs does seem to determine then- function to be the cooling of the body by exposing the blood in a large surface to the air : and I shall, without embarrassing the subject with the supposed chemical changes which occur in the lungs, proceed to prove that such is the exist- ing economy of the animal. Although it may be doubted whether breath- ing be for the purpose of carrying off the super- abundant heat of the animal, yet no such doubt exists on the use of perspiration ; the utility of which, in cooling the body, is now universally admitted. In those animals, however, whose F 2 68 nature it is, not to transpire, of which the dog is a familiar instance, the cooling process is evidently effected by the lungs ; his quick and laborious breathing after running, ceasing only as the body becomes cool. Now, if respira- tion had been for the purpose of supporting animal temperature, surely this hurried function of the lungs, where the heat was already too great, must have been unnecessary; and, to suppose their function reversed under those circumstances, would be taking a most unjusti- fiable latitude of argument. To explain an effect common to life, its source should be sought in some operation common to the nature of all animals : now, although all animals generate heat, yet they do not all breathe ; it would be impossible, therefore, to explain the source of heat in non- respiratory animals, from the oxygen they consume. All living beings must, however, be endued with sensibility : in considering animal heat as evolved during the operation by which sensibility is accomplished, we have, therefore, a source of it in all animals ; in which respect it has an evident advantage over the commonly-received theory. Hitherto we have considered only the inhabitants of the 69 air ; there are other animals which now claim our attention in connection with the present subject : in treating of them we must revert to the laws of natural philosophy as ascertained and admitted by experiment and reason. It is a well-established fact, that sounds are more powerful, conveyed through a dense than through a rare medium ; this is proved by observing how much further any given degree of sound may be heard along water than through the air, and through the denser media of wood and iron, than through either air or water ; while the vibrations of sound made in the receiver of an air-pump become less audible as the air is exhausted and becomes rarer, ^ronauts have remarked, that when at a great elevation, they lose their power of hearing; this is a deception in acoustics, as that power, considered abstractedly, is not altered; but the rarity of the air, which has less power of con- veying sounds, leads to the imperfection in hearing. In a late ascent to the summit of Mont Blanc, the adventurers observed that one of the most remarkable features of their situation was the universal stillness. It was observed, by a celebrated traveller, that one of the most singular circumstances which struck 70 him in visiting the falls of Niagara, was the distance at which persons might be heard even when speaking low : in this district there is always a very dense state of atmosphere. The density of transparent bodies has also an in- fluence upon light, as is seen in the laws of refraction. And that the medium through which the sense of feeling is affected has con- siderable influence, may be proved by the different degrees of heat which can be borne when applied through the different media of water, vapour, and air : the body will bear about one hundred degrees of heat through water, one hundred-and- thirty through vapour, and about two hundred through the rarer medium of air. Now, as animals are so much more easily affected through a dense than through a rare medium, they whose natural element is the dense medium of water, will require, to place them in a proper relation with the laws of heat, light, sound, &c., a much lower degree of sensibility than those animals whose natural element is the rarer medium of air. If, then, the operation from which sensibility results be the source of heat, and animals dwelling in the dense medium of water require low degrees 71^ of sensibility, it results as a necessary conse- quence that but little heat will be generated, and hence those animals will have blood of so low a temperature as to be termed cold-blooded; and to them lungs Woulid be useless. Th^e nature and functions of these animals accord with all that has been advanced upon the uses of organization ; they have a languid circula- tion, generate but little heat, consume but small relative quantities of food, and soon undergo the putrefactive process after death : and their assimilative organs bear a very small proportion to their bulk. [These facts may be observed in a contemplation of the nature of fishes.] There is another class of animals capable of living both in the dense medium of water and in the rarer medium of air. The natural history and habits of these animals (amphibiee) further support these opinions of the uses of the assimilative functions, the source of heat, and the use of the lungs. In these animals, thelungshave been considered (without sufficient reason) to be under the influence of the will, but whether this be the case or not, it is clearly a matter of- fact that they are used when dwelling in the rather medium of air, and fall into disuse 72 in the dense medium of water. This can hardly be allowed to arise from caprice in the animal, and it is still more difficult to admit it an useless arrangement of the Great Designer of their being. But, keeping in mind the known circumstance of sensations being more easily excited through the dense medium of water, and consequently the lesser degree of sensibi- lity required in that situation, and the further consequence of a lesser evolution of heat, it becomes easy to perceive that the lungs become quiescent in the water because their use is no longer required. But when those animals are subjected to extraordinary excitement, even in this dense medium, they are under the ne- cessity of occasionally rising to the surface to cool by breathing, their heated blood, as is observed in the otter when hunted, and in the whale : this breathing is termed blowing. The higher degree of sensibility required in the rarer medium of air, and the consequent greater generation of heat, renders a regular and unre- mitting breathing necessary on land. [Thus we have a rational explanation of the pheno- mena of amphibious animals]. It is difficult to estimate the breathing structure of insects by an appeal to anatomy. 73 but experiment and reason prove the extensive permeability of their bodies to air, without which they cannot live ; and it has been proved by Spallanzani, that they deteriorate a greater relative quantity of air than the larger animals. These animals, dwelling in the rare medium of air, must of necessity, from the smallness of their bodies, have great degrees of sensibility : they must consequently generate great heat, breathe extensively, consume great relative quantities of food, have large abdominal development, and they will be late in the chemical decomposition of their bodies after death. [These facts may be observed in con- templating the nature of insects]. There is another property of living animals now claiming our attention as essential to the knowledge of individual life, and a necessary preliminary to an extended understanding of the general principles of animal existence : this property is muscular motion — the subject of the next chapter. CHAPTER VI. Muscular motion — consists in the simple property of contracting — is dependent upon nervous agency*'^ Electric Jluid is capable of exciting tnuscles to con- tract — Dr. Ure's experiment — Argument and facts in support of the ideiitity of electric Jluid and the natural cause of muscular contraction — Concluding remarks. THE multiplicity of actions in living' bodies may at first appear to involve this subject in great difficulties, but when it is known that the immense variety of motions — the slow progression of the large unwieldy animals, the elephant, rhinoceros, &c. — the amazingly rapid progression of some of the smaller animals — the easy and graceful actions of the dancer — the sweet smile of satisfaction — the laugh of merriment— the quivering lip of fear — the sar- castic sneer of scorn — the beating action of the heart — the ever-labouring motions of breathing — the peristaltic movement of the stomach and intestines, the absorbents and lacteals — are the result of one simple property of flesh, this rough and discouraging prospect becomes a path of comparatively easy ascent. Of the 75 ultimate molecules of muscles, we know no more than of the infinitesimal particles of other matter, but to our inquiry it is sufficient to consider muscles as fibrous flesh possessing" the property of contracting ; they are called voluntary or involuntary as they are depend- ent or not upon the influence of the will for the exercise of their contractile powers. Of whichever class they may be, whether de- pendent upon the will or not, nervous agency is necessary to their action, since the division of the nerve supplying a muscle or pressure upon it, will totally suspend or interrupt its function of contracting. Experience teaches also that an evolution of heat is a constant accompaniment to the exercise of these organs^ The property of contracting in muscles was not known to have any connexion with the common laws of physics, until, by accident. Professor Galvani, of Bologna, observed the muscles of some frogs, which had been skinned for experiment, were convulsed, or showed re- peated contractions, every time a spark was taken in some electric experiments. Since this discovery, animal motion has been sup- posed to be in some manner dependent upon a fluid, some of the phenomena of which were before known, and having been first observed 76 in electrum or amber was called electric fluid. After this discovery of Galvani, it has been called, especially when used in animal experi- ment, Galvanic fluid. Since this time, the power of electric or Galvanic fluid in exciting muscular contraction has been fully admitted, and numerous experiments have been made with it, but the most striking example of its influence is to be found in the experiment made by Dr. Ure of Glasgow, which is in sub- stance thus recorded : — *'The subject of this experiment (a mur- derer) was a middle-sized, athletic and ex- tremely muscular man, about thirty years of age. He was suspeudedfromthe gallows nearlyanhour. The voltaic battery consisted of two hundred and seventy pair of four-inch plates, which were brought into intense action with a dilute nitro- sulphuric acid. A pointed rod, connected with one end of the battery, was applied to the pos- terior part of the spinal marrow at the atlas vertebra, while the other rod was applied to the sciatic nerve. Every muscle of the body was immediately agitated with convulsive movements, resembling a violent shuddering from cold. The second rod was then applied to a small cut made in the heel, the knee being 77 previously bent ; the leg was thrown out with such violence as nearly to overturn one of the assistants, who in vain endeavoured to prevent its extension. " By transmitting the Galvanic influence through the phrenic nerve in the neck, and making a communication by the application of a rod to the great head of the diaphragm, this muscle, the main agent of respiration, was instantly contracted, but with less force than was expected. By a different mode of appli- cation of the Galvanic influence, full and labo- rious breathing instantly commenced; the chest heaved and fell, the belly was protruded, and again collapsed with the relaxing and re- tiring diaphragm. The supra-orbital nerve was laid bare in the forehead ; one conducting rod being applied to it and the other to the heel, most extraordinary grimaces were exhi- bited every time the electric discharges were made. By running the wire in my hand along the edges of the last trough, from the two hundred and twentieth to the two hundred and twenty-seventh pair of plates, every muscle in the countenance was simultaneously thrown into fearful action ; rage, horror, despair, anguish, and ghastly smiles, united their hideous ex- 78 pression in the murderer's face, surpassing the wildest representations of a Fuseli or Kean. At this period, several of the spectators were forced to leave the room from terror and sick- ness, and one gentleman fainted. "By transmitting the electric power from the spinal marrow to the ulnar nerve, as it passes by the internal condyle at the elbow, the fingers were nimbly moved like those of a violin performer; an assistant who tried to close the fist found the hand to open in spite of his efforts. When the one rod was applied to a slight incision in the top of the fore-finger, that finger extended instantly ; and, from the con- vulsive agitation of the arm, he seemed to point at the diff'erent spectators, some of whom thought he had come to life." The agency of electricity, in exciting both the voluntary and involuntary muscles to con- traction, is here decisive, and the identity of that fluid, with the agency by which it is per formed in a living animal, may be fairly assumed, if not fully proved, upon the following grounds. Muscular exertion is always attended by an evolution of heat, and the same circum- stance always accompanies electrical operations. f9 In those instances where a supply of electricity- is interrupted, either by deficient quantity, or deteriorated quality of the food, or by imper- fection of the digestive and assimilative func- tions, or where electricity is unnaturally exhausted, either by febrile or inflammatory diseases, or by excesses, there is always accompanying great muscular weakness. And an excessive exertion of this property (muscular contractility) is attended with all the concomi- tants of exhausted electricity — the over-excited animal loses in an instant its sensibility, and consequently its relation with the laws of the material world, the contractility of its muscular fibre becomes extinct, and its flesh remains flabby, its blood will not coagulate, and it immediately putrifies or runs into chemical decomposition, as is exemplified in animals who drop down dead from over-exertion, as race-horses, hares, greyhounds, &c. This state is exactly similar to that produced by exhaus- tion of the electric fluid, by excessive arterial action. Destruction by lightning sometimes produces the same features in dead animals. That that faculty of the animal which is recognized in the act of volition is capable of projecting electric fluid to the muscles may 80 readily be admitted, upon principles of the closest and most correct analogy, when it is known that some animals are capable of pro- jecting it at will from their bodies, and producing its powerful paralysing effect, as is well authenticated in the accounts of the torpedo, gymnotus, and silurus electricus. The natural histories of these animals aiford truths which give a reflective brightness to the previous reasoning upon the ultimate uses of the assimilative functions and food-taking. **They become, from over excitation, much impaired in all their electrical and animal powers, and fall into a torpid state, from which they do not recover and regain their electric powers, without long rest and considerable supplies of food : " which latter circumstance is proof of the source from which their electric power is derived ; and it is universally known, that exhausted muscular power is only capable of being restored from the same source. Those muscles, or muscular organs, which are not designed for loco-motion, but whose movements (termed organic) are essential to the support of those operations which immedi- ately keep the animal in a proper relation with the laws of the material world, are placed 81 independent of the will, and have their electrical influence through a separate and distinct system of nerves, and their electrical influence is directed by causes purely physical : while all voluntary muscles have an immediate nervous connexion with the brain or spinal marrow, and their exertion is influenced by a recognized faculty of the soul, the action of which is termed volition. A close analogy bearing upon this, is the influence of nerves in accomplishing digestion, which has been proved by Dr. Wilson Philip ; and his experiments give a decided proof, that the nerves are pervaded by some subtle principle which he infers to be identical with electric fluid. He is also of opinion, that in its applica- tion to arterial blood, it is capable of occasion- ing an evolution of heat. The experiments of Mr. Brodie go also to prove the cerebral or nervous system to be the source of heat. It should appear, therefore, that in the living animal there are three series of electrical operations, and consequently, three distinct sources of heat. First, that constant state of electric excitement which preserves a continual electrical influence toward the soul, and con- G 82 stitutes sensibility : this is the constant and great cause of animal temperature. fSecondly, that occasional state of electrical excitement, which, by an influence from the soul, termed volition, accomplishes muscular motion : this is an occasional cause of great increased animal temperature. Thirdly, that electrical excite- ment which by a purely physical influence accomplishes the organic movements essential to life ; and which also influences the animal changes which occur in digestion, &c. : this is a constant but minor cause of animal temperature. These three series of electrical operations, the physiological researches of the present day, particularly those of Mr. Bell, are demon- strating to be accomplished by three distinct systems of nerves. CHAPTER VII. He-view of facts and p7'oof of 2)ropositio)i — The simul- taneous existe7ice and destruction of the physical pro- perties of living animals — A clear iiitelligible and rational view of a living anijnal —atid of the animal creation generally — A practical inference. NOW, to condense the spirit of the foregoing facts, and to sum up into a narrower compass for re- view the force of the accompanying argument, in which is involved the proof of the proposition on the operation which takes place between the arterial and nervous systems in accomplishing sensibility. The observation and experiments of mankind in latter years, have discovered, in the physical world, a subtle agent which they have termed electric fluid. Whether this principle has an exact correspondency with our idea of fluidity, and, if so, whether the term electric be the most appropriate word to designate it by, are matters of trifling importance in this place. This principle (designated by them the electric fluid) has the property, if passed through a 84 living animal body, of making- a strong impres- sion upon the perceiving power of the soul ; and the nature of that impression, as may be ascertained by experiment, is altered by the organ of sense through vv^hich it is transmitted ; so, that if it be through the skin, it gives an impression of contact ; if through the ear, of sound ; if through the eye, of light; if through the nostril or mouth, of odour or taste. This principle has the property also, when trans- mitted through the nervous system to muscles, of exciting them to contraction; the act for which they are naturally designed. The phe- nomena of this principle are also always ac- companied by an evolution of heat. And some experiments of Sir Humphry Davy, prove its power of restraining chemical affinities. While the fact of its being given out voluntarily for defence by some animals, shows its capability of being subjected to the will. Now, as the phenomena of animal life can be so clearly understood, and so readily explained by the agency of a subtle principle having these powers, it is, if those properties of the animal are found to have a simultaneous being, and consequently a dependence upon one common cause, a correct inference, upon the purest and most legitimate exercise of reason, that this 85 fluid (the electric) is the identical agent by which those properties of animals are main- tained. In a healthy living animal, those properties of which we have been treating have a simulta- neous existence. And, serving both as proof and illustration of the simultaneous destruction of these properties, and consequently of their dependence upon one common cause, may be brought forward those animals who die by lightning, in which case their electricity is sometimes suddenly and instantaneously ex- hausted ; and, as suddenly and instantaneously are destroyed their sensibility, muscular con- tractility, their power of generating heat, and of restraining chemical affinities. In a future examination of Disease, we shall be able to trace a simultaneous gradual destruction, and simultaneous gradual revival, of these properties in animals. But, to bring these opinions to the test of experience, the touch-stone of truth, it will be desirable to examine fairly, whether they afford a clear, intelligible, rational, and useful idea of a living animal; and whether the pheno- mena of life, in health and disease, be not 86 better comprehended and understood, and a more rational basis formed for the practice of medicine, than upon any notions of life yet advanced. We may then proceed to discuss fully the doctrine of Materialism, and to inquire whether the notion of a future existence, and that in accordance with the general language of the Christian Scriptures, and the express language of the apostle Paul, be compatible with the truths of philosophy. The opinions afforded by the foregoing rea- soning are — that in every living animal, there are certain faculties or attributes to which, when considered abstractedly, may be appro- priated the term * anima' or ' soul' — that life consists of a relation between such attributes and the physical laws of the material world — that the body is the medium or instrument by which such relation is accomplished — that sensibility, muscular contractility, the organic movements, and animal combinations, depend upon the agency of electric fluid — that the ulterior use of food-taking is the supply of electric fluid — that the rapid circulation in animals is always in accordance with their degree of sensibility — that in the operation between the arterial and nervous systems as well as in 87 muscular contraction and organic movements, heat is evolved — and that the use of the lungs is to cool the body. Upon these opinions, we do attain a clear, intelligible, and rational idea of a living animal individually ; and we attain a clear, intelligible, and rational view of the animal creation in general. Casting our eyes around, we see a vast assemblage of living beings, varying in shape, size, and structure, in their capacities and habits; inhabiting all nature, spreading over the face, and delving into the inmost recesses of the earth, rising and teeming in the circum- ambient atmosphere, diving into the deep bosom of ocean, and crowding with their presence even the fluids we are destined to drink, and the food we exist upon ; each being equally perfect in itself, having an organized body adapted to its destined habits, and suited to its wants and situation. In every individual of this immense congregation, we recognize the power of perceiving, and therefore, take that faculty as the great distinguishing feature of this order of being. We have a perfect example of life, in every being having an established relation be- tween its faculty or power of perceiving and any of the natural laws of the material world ;, 88 while the more extended relation with those physical laws made by the super-addition of other organs of sense, afford us varieties of animated beings at once wonderful and instruc- tive, wonderful in one intelligent principle perceiving through several sensible organs, and instructive, in that it leads us to the opinion of its capacity for more, and even an indefinite number of sensible organs. The complicated structure and varied functions which anatomy and observation present to our consideration, we regard as all tending to the support (being servient or subservient to the convenience) of this relation (or life). The bony fabric of our frame is the well-adjusted foundation of the super-structure of the body ; the voluntary and involuntary muscles, the simple instru- ments of animal and organic movement ; the structure and functions of the brain and nerves, the heart and arteries, the veins, the mouth with its glandular appendages, the stomach and intestines, the liver, the lungs, the kidneys and bladder, the functional power of the skin, the absorbents and lacteals, we regard as all labouring in the support of this relation between the soul and the physical laws of the material world. The animal organs or instruments adapted to the laws of the ever-varying light 89 and sound, we see furnished with regulators to keep their powers constantly fit for accom- plishing this relation. We do not acknowledge an unnecessary and useless decomposition and re-formation of living bodies, nor do we suppose animals encumbered by a complicated organi- zation (the pulmonary apparatus) for the purpose of making them warm-blooded, a circumstance unnecessary to existence, and therefore regarded by us as adventitious. We know the cause why infants have a very rapid circulation, hasty digestion, and high tempe- rature ; also, why they have greater relative abdominal development, and consume such greater relative supplies of food, and why all these processes and results diminish, as the animal increases in size. We learn also, why the larger animals have relative slow circulation, and comparative small abdominal development, and consume small relative supplies of food. We perceive why animals are not all warm- blooded, and that it does not arise, as has been supposed, fromcapriceintheir Designer, but is a necessary consequence resulting from the situation in which they are placed by Him, of infinite wisdom and power. These opinions, therefore, afi'ord at least as clear, intelligible, and rational an idea of a living animal, as any 90 theory heretofore given ; audi shall, in the next chapter, proceed to inquire, whether it be not more useful in explaining the phenomena of disease, and in forming the basis of practical medicine, than any notion of life heretofore advanced. In the mean time, I must observe, that the first practical inference to be drawn from these opinions, is one of so much importance, that it should be indelibly imprinted in the minds of all medical practitioners, and enforced in every school of medical science in the kingdom, viz : that where the sensihility of the animal is correct there the pulse is correct. There is no practice in medicine so fatal and destructive as an officious interference with the pulse. How often do we see all the efforts directed to reduce the frequent pulse of exhausted patients? And yet this more frequent beating of their arteries is the salutary effort of the animal economy to keep up the requisite sensibility of the individual, as we see in the starving man, and in the woman almost dead from excessive uterine hBemorrhage. Transfusion of blood from another person, or gradual repletion of the circulating system by nutriment, are the only effectual means of producing a desirable and 91 permanent reduction of pulse in these cases. The effect of digitalis and other medicines directly sedative to the arterial system, is to produce in these cases with diminished arterial action, coldness of the extremities and surface, indistinct vision and hearing, (which from its resembling that indistinct sensation experienced from turning the head very quickly round, is called vertigo) faintness, and if given very largely, death. CHAPTER VIII. Pathology. — Its object — Inflammation — Fever — Typhus — a result of fever — its forms — Sea-scurvy — Fainting — Hectic fever — Consumption — Soyne other Diseases — Conclusion. THE utility of a doctrine of life as the basis of practical medicine, consists chiefly in its affording a rational explanation of the pheno- mena of disease, upon which only can be founded a rational method of cure. In testing the truth of these opinions by an appeal to experience in disease, I shall, instead of taking the symptoms of any given malady, and then explaining how they may be supposed to arise upon the principles herein maintained, trace what would naturally result from certain dis- orders of the animal functions, if these opinions be true ; and if such phenomena should accord with the acknowledged descriptions of diseases, it will afford both a proof of the truth and utility of this doctrine of life. In the first place, if there should occur an unnatural increase of action in a sensible part. 93 there would necessarily be an accompanying unnatural increase of those phenomena which have been supposed to arise from the combined action of the arterial and nervous systems ; these are the properties of sensibility and heat : this unnatural degree of sensibility would unfit the part for bearing those impressions which at other times it had borne with ease ; and the organic operations, which in a natural state of the sensibility are not perceived, would now become apparent to the perceptibility of the animal ; and hence a tormenting sensation of throbbing, and burning, and a great tender- ness on contact : these phenomena with swell- ing, and in red-blooded animals increased red- ness, both natural results of an unnatural ful- ness of the vessels, would constitute a disease, which has been called Inflammation. This is the greatest extent in which M. Bichat's mean- ing can be justly received, when he asserts that organic may be changed into animal sensibility. This disease of increased sensibility occurring in the organs of seeing, hearing, smell, or taste, will in the first two produce intolerance of the physical laws by which seeing and hearing are effected, and in the^last two, the powers of discriminating savours and odours will be destroyed. If it occur in the 94 stomach, liver, lungs, kidneys, bladder, intes-- tines, or heart, it will, besides the painful affection and increased heat, be accompanied by such interruption of the functions of those organs as is seen in the study of diseases ; but upon which it will be unnecessary for me to dwell. Further, if the unnatural action be so much increased as to exhaust the electric fluid faster than the animal powers can supply it, the sensibility and heat will, in such case, become intensely increased, and then suddenly cease, and the principle being exhausted by which chemical affinities had been restrained and heat evolved, those affinities will now be exerted, and all the phenomena of putrefaction will present themselves : this will give all the characters of mortification — loss of sensibility, coldness, and a return to chemical affinities. This result of disease will be most likely to occur in children, from the rapid expenditure of electricity in them for the support of their lives ; or in very old persons, where the diges- tive powers, the source of its elaboration from food, are become weak ; or in persons of in- temperate habits, whose digestive powers have been prematurely impaired ; or in persons of a depraved state of body from oth^r causes. Should this unnatural increase of action be general, there would necessarily result an unnatural increase of sensibility generally, together with a general increase of heat ; this latter symptom would not only be experienced upon the surface of the body, but the respired air would be returned much hotter than usual : while the organs of sense being all altered in their powers, the individual would not perceive with his usual correctness, nor would he con- sequently retain, compare, compound, and abstract, nor will, nor feel in his passions and affections-, as he was wont to do in his usual and natural state of sensibility ; hence his conduct would present those aberrations which in fever (the subject in contemplation) is called delirium. The same temporary aberrations are observed where the sensibility is altered by intoxicating liquors : and some drugs having a powerful effect on the sensibility also produce this state. Local inflammation, if of consider- able extent, is accompanied by an increase of heat in the body generally, also by an increase of heat in the respired air, and a hurried state of the circulation ; these then con- stitute symptomatic, or sympathetic fever. As in inflammation, so in a general increase of circu- lation, if the exhaustion of electricity be greater 96 than the animal powers can supply, there must result a general tendency to insensibility and putrefaction, great muscular debility, and cold- ness ; this is the modified stage of fever to which the term typhus is applicable. The many discrepancies in opinion concern- ing the nature of typhus fever, and the variety and opposite treatment adopted in its cure, result from the obscurity which has over- hung the nature of fever in general. Typhus fever is by no means that regular and unvarying disease, which, like small-pox, measles, and scarlatina, will admit a general description of its course. The term typhus, is applicable only to a state which is the result of disorder, and this result may be the conse- quence of several derangements in the animal economy. The symptoms which are embraced in my idea of the term typhus, are, diminished sensibility, great muscular weakness, coldness of extremities and surface, the secretions and excretions putrefactive, the mental powers much diminished, and a general tendency to putrefaction in the solids, so that wounds become gangrenous, and blistered parts mortify. Now let me ask those who are conversant with the nature, history, and course of Disease, 97 whether this state, as connected with fever, does not present itself under many forms, among which are the following- : — A man in perfect health, and of great strength, is suddenly seized with pain in the head from what is called a coup de soleil, or from some cause not apparent. He exhibits, in a little time, all the symptoms of phrenitis and fever, great increase of arterial action, great increase of heat, great increase of sensibility, so as to be intolerant of light, sound, and heat, high delirium, and, if he exerts his muscular powers, great muscular energy. In a few hours, perhaps seventy or eighty, or even less, especially in tropical climates, when this unnatural state has much exhausted the electricity of the body, his state presents the symptoms of typhus — diminished sensibility, great muscular weak- ness, coldness of extremity and surface, the secretions and excretions putrefactive, low delirium, and a general tendency to putrefac- tion in the solids if wounded or blistered. A man not very healthy or strong, subject perhaps to many symptoms of dyspepsia, and of an irritable habit, sleeps in damp sheets, is exposed to a cold rain in travelling, or, perhaps, H 98 while under ail unusual course of exertion, gets his feet wet, and soon after, perhaps a day or two, has fever, unaccompanied by any very high degree of excitement. This does not subside so soon as might be expected ; and, after continuing perhaps a fortnight, he presents the gradually increasing symptoms of typhus — diminished sensibility, muscular weakness, coldness of extremities and surface, the secre- tions and excretions putrefactive, mental powers much diminished, and a general tendency to putrefaction in wounds or blistered places. Another very common course of disease, afford- ing typhus as a result, is that embraced in Dr. Hamilton's excellent and concise description : " Some derangement of the stomach, marked by loss of appetite, thirst, sickness, white or loaded tongue, disagreeable taste in the mouth, and most commonly a constipation of the bowels — precedes head-ache, languor, debility, and inaptitude for the usual mental and bodily exertions ; morbid affections of the surface of the body, of the sanguiferous system, and of different secretions, soon succeed ; to which, in the more advanced stage, delirium, subsultus tendinum, floccitatio, and singultus supervene." [See p. 31, seventh edition.] 99 In crews, garrisons, or any collections of men where provision is short or deteriorated, all their febrile diseases do, in the advanced stages, present symptoms of typhus. After a wet and bad harvest, where the corn lias been deteriorated by germination, febrile diseases have a tendency to afford rapidly the symptoms of typhus, more especially among those whose diet is chiefly farinaceous. Contagion, and some poisons whose modes of acting are not understood, but which pro- bably exhaust very suddenly the animal elec- tricity, do afford rapidly the symptoms of typhus. From this, it must appear, that the terms * Typhus Fever,' are not expressive of a peculiar and regular disease, but that they merely indi- cate those fevers accompanied with the symp- toms embraced in the term 'Typhus'; whether from cold, contagion, the ordinary effects of fever in debilitated constitutions, or any other cause. Typhus may also be seen to accompany measles, small-pox, scarlatina, or any other febrile disease. And the sympathetic fever accompanying local mortification, is marked u 2 100 by the symptoms of typhus. The next subject of consideration, in prosecuting these views, embraces the circumstances connected with life and food, and this will afford an instance of typhus without fever. It has been maintained in this Disquisition, that the source of animal electricity is food. If then, from long keeping, or other unfavour- able circumstances, the food upon which a crew were subsisting had suffered a great loss of that principle known by its approach to putrefaction, it would be a necessary conse- quence, that the animal powers of those who suffered this deprivation should suffer in all those points which depend upon electricity for their support : hence great muscular weakness, an approach to insensibility, faintness, a pu- trescent tendency in the fluids, coldness of body, putrefaction of wounds and blistered places, and sudden death on slight exertion, would be the natural result. Such a state, under such circumstances, does occur, and constitutes the disease termed Sea-scurvy ; in which is seen typhus without fever. [See Lord Anson's Voyages : or refer to any history and description of this disease.] 101 If the action of the circulation be interrupt- ed, or suspended, by sudden loss of blood, by- disease of the heart, or any other cause, there must necessarily result an interruption or sus- pension of sensibility, and there will be im- perfect, or total destruction of, vision ; indis- tinct, or total destruction of, hearing ; loss of smell, taste, and touch ; the power of the will over the muscles will also be impaired or de- stroyed ; and there will be coldness of the body : such a state does occur from those causes, and is called Fainting or Syncope. The revival from this state presents the natural order of the series of the vital operations, and further proves the truth of the opinions herein maintained: — the powers of the circulation recover, the pulsatory action commences, a return of heat is gradually effected, and with it the sensibility of the body ; the lungs then commence their action, and at first the air expired is cool, then warmer, and at length, when the proper degree of sensibility is esta- blished, the breath acquires its usual degree of heat. Animals killed by bleeding or interruption of circulation, retain their electricity for some time, and hence do not putrefy so soon as those 102 who are destroyed by lightning, or diseases which exhaust that principle. It has been, in the physiology of this system, maintained, that the office of the lungs is to cool the blood, by exposing it in a large surface to the air. If, then, the functional power of a part of the lungs be destroyed by disease, of whatever nature it may be, the animal will no longer be capable of ridding itself of its super-abundant heat in the usual manner ; but, as the skin has the power of cooling the blood by throwing off fluid, and thus producing evaporation, the animal will thus be cooled for some time. This occurrence takes place in what is termed hectic fever : in that disorder is seen a gradual accumulation of heat, which, on reaching a certain point, terminates in per- spiration ; ' then another accumulation and perspiration ; and these returns of accumu- lated heat keep pretty regular periods, and, when very distinct and palpable, may be con- sidered the most certain proof of diseased structure or function of the lungs. The ever- living hope of consumptives is by reason of their experiencing no disturbance in the ex- ercise of their intellectual faculties, which remain unimpaired as long as the functions 103 can keep them in relation with the laws of the material world. It is, when this relation be- comes imperfect from the weakened state of the organic powers, that the patient first be- comes aware of danger ; and this feeling is the first indication of approaching dissolution. If consumptives, who have been very sanguine of recovery, and who have suddenly become conscious of their dangerous situation, be asked why their opinion is thus hastily changed, their reply is, that they are now convinced of their weakness ; but, if it be thought, and pointed out to them, that their weakness can- not be so much increased since they were last seen, they reply, that it is. The explanation of the fact is, that the weakened animal powers are now no longer capable of keeping the anima or soul in relation with the laws of the material world, and vision has therefore become imperfect ; sometimes hearing obtuse ; and the command over the muscles diminished. If asked expressly upon these points, they ac- knowledge the truth of the suggestions, but beg not to be troubled, as the slightest exer- tion is now a painful effort. If consumptives do not die suffocated, or in a fainting fit, both of which are very common terminations, they present, in their last stage, the symptoms em- 104 braced in the term Typhus, except the coldness of the surface ; and this modification arises from the accumulated heat consequent upon the destruction of the breathing (or cooling) apparatus. There is a series of diseases so numerous and multiform, that to attempt any thing like a separate description of them, would be the commencement of an endless task, as the symptoms are scarcely ever the same in any two individuals. 1 allude to that immense variety of diseases which have their origin in derangement of the assimilative functions, and which are embraced in the vague meaning connected with the terms dyspepsia, indiges- tion, chlorosis, scrophula, tympanitis, chorea sancti viti, hypochondriasis, &c. &c. In this immense class of diseases, some word indica- tive of the most prominent feature is gene- rally adopted to characterize it, but the origin and cause of nearly all may be found in the assimilative organs, as is proved by the success of the practice adopted by Hamilton, Aber- nethy, Philip, and Hall. The descriptions by the latter, in his book on the Mimoses, are faithful portraits of singular disorders from the same origin. The prominent features of 105 these diseases— deranged sensibility either increased or diminished— the varying heat — muscular weakness with irregular muscular action — together with the depraved and ap- proaching-to-putrefactive state of the secretions — may be more clearly comprehended upon these views of physiology, than upon any rationale which has ever been proposed to ac- count for them. But to show the extensive connection with the phenomena of life, health, and disease, which these opinions have, would carry me too far, and lead into discussions which will be better detached ; inasmuch, as after a close observation for a considerable period, I have met with no circumstances with which they do not accord. We may, therefore, consider this system to afford at least as rational an explanation of the phenomena of disease, and as useful a basis for practical medicine, upon which may be founded as scientific a method of cure, as any system heretofore advanced. And while it leads to a more mild and safe practice than that usually adopted, it tends also to a more energetic and more ardent course in cases of exhaustion, than the system of those physiologists who say that life may be 106 considered as made up of a given number of pulsations, and who teach the husbanding of these to be the great secret of prolonging its duration. CHAPTER IX. Examination of the arguments in favour of Material- ism — M. Bichafs argument concerning organic and animal Sensibility — is sophistical — A physical no- tion of life has insuperable physical objections — The reasoning of Materialists upon cause and effect — is not sound — Contrary to the assertions of the Materialists, the soul may be defined, is evidenced by the senses, and has palpable proof in its effects — The size of the brain — gives no support to Mate- rialism — but is in direct opposition to it — The pro- bable use of the brain — Conclusion — isi7i accordance with the possibility of a future life — and that as taught by the Christian Scriptures, I COME now to resume the discussion of the question of Materialism ; in doing which, I shall enter into a fair and impartial investiga- tion of the most cogent arguments of its sup- porters ; afterwards compare it with the .opin- ions of life herein maintained, and then pro- ceed to investigate the rationality of a future life. 108 The doctrine of Materialism supposes, that a certain arrangement of material atoms, com- bined with peculiar actions, give, as the result, all those phenomena which the varied animal, as well as the physical world present to our consideration. That the faculties of perceiv- ing, retaining, discerning, comparing, com- pounding, and abstracting, ideas ; the power of willing ; and the capacity for passions and affections ; are all results of this same arrange- ment of material atoms. The advocates of this doctrine have given their assent, and fully confided their belief in this opinion upon the circumstance of this material arrangement being essential to the demonstration of those powers or faculties. And, an argument of M. Bichat's, in which there is a palpable fallacy, has been thought to add much support to this opinion : I allude to his assertion, " that organic sensi- bility may, by disease, be heightened into animal sensibility :" and, as organic and vege- table sensibility are considered the same, here has been supposed a direct proof of animal life being nothing more than an exalted state of organic or vegetable vitality. The sophism here, is in supposing that the excess of any given property can constitute another pro- perty. Let the property of organic or vege- 109 table sensibility be defined in any manner whatever, an excess of that property, according to the definition, cannot constitute the pro- perty of perceiving, any more than an excess of sweetness could constitute light, sound, or madness. Herein is seen the importance of attaching clear and definite ideas to the terms Perceptibility and Sensibility, in order to comprehend and render intelligible the cir- cumstance of disease alluded to by M. Bichat. This phenomenon, to which he has so particu- larly directed the attention, and on which he has founded his doctrine, may be thus intel- ligibly understood. The perceptive power of the animal has a distinct existence ; the sensi- bility of the animal is for the purpose of con- veying impressions to that faculty, but it is not designed that the organic operations should excite the act of perception; these actions must, however, necessarily approach very near to the accomplishment of that act, in order that any further impression coming upon the part, may readily excite perception ; now, if these organic operations be by disease carried too far, they become themselves a cause of the act (not the poicer) of perception ; and the beating of the artery, together with heat, are the objects perceived by the anima or soul. no To this physical notion of life of the Mate- rialists, there arise insuperable physical ob- jections. First, It is an admitted principle in physics, or natural philosophy, that similar causes should produce similar effects ; and, by parity of reasoning, that similar effects should be the result of similar causes. It follows, then, that life in animals similarly situated, should result from,, and be maintained by, equal operations ; but this is contrary to ex- perience, since the degree of organic operations, which afford life to the large animals, appear incapable of effecting it in the smaller ; while the degree of organic operations which afford the life of the smaller animals, would render the larger incapable of inhabiting the same world. Secondly, It is an admitted principle in physics, that when causes be removed, effects should cease. Accordingly, if the faculties as well as the demonstration of the faculties of the soul, were the result of organization, it should necessarily follow, that the destruction of the organization by which those faculties were demonstrated, should be accompanied by a destruction of those faculties. Thus, if from the peculiar structure and function of the eye and its appendages, in which I conclude a portion of the brain, the jwwer, as well as the Ill act of perceiving, retaining, discerning, com- pounding, comparing, and abstracting, the ideas of light and its modifications of colour and form, arose ; then, it should follow, that with a destruction of that organization should fade all the knowledge (an effect) which had thus been obtained by this faculty of organization. This is contrary to experience, since the know- ledge of light, with its modifications of colour and form, may be, and is, retained, &c. when the destruction of that organ (the eye) is com- plete. The same reasoning is applicable to the other senses, and also to the other facul- ties. Another objection to this doctrine of Mate- rialism is, that in disease, more especially in putrid fever, the whole organized body may become involved in an almost destructive rot- tenness, and so much changed as to render all the animal phenomena disordered ; yet, on a renovation of that organized body by a fresh supply of material, the former ideas, opinions, powers, and affections, are restored. And cases of deranged mind are not wanting, in which, after a lapse of many years, there has been a return to former associations, affections, and habits. And, indeed, the nature of the 112 act of recollection, especially when exercised upon things which have been many years before received and contemplated, appears to invalidate the system of Materialism ; and it does conclusively prove that Materialism, and the notion of a continual wearing away of the body, cannot possibly both be true. Because, if, after a period, say four, seven, or ten years, there be a complete renewal of the organized body, and organization be the cause of the intellectual faculties, how can the identical ideas and feelings, which had been effected by the former body, be accomplished by this changed structure, as we see daily in the act of memory when exercised upon occurrences of many years past ? Of the moral objections to the doctrine of Materialism, it is not my province to treat. But the basis of them is, that if the intellectual faculties be the result of organization, then with disorganization, there must come a com- plete destruction of the whole, and it supposes physical influence the sole and irresistible mo- tive in conduct. The believers in, and supporters of, the doc- trine of Materialism, have not rested their 113 assent, nor grounded their argument upon any connection, as cause and effect, discovered between organization and those recognised faculties of the animal to which I have appro- priated the term Soul ; but they reason thus : — Our knowledge is confined to cause and effect ; we have no knowledge of a power of perceiv- ing, until it is recognised by us in the act of perceiving ; the act of perceiving is accom- plished only by means of organization : there- fore the power of perceiving is the result of organization. To bring this mode of reasoning to the test of experience, let us apply it in explaining the property of a telescope. Our knowledge is confined to cause and effect ; we have no knowledge of the ring of Saturn, until it is recognized by us in the act of per- ceiving it ; the act of perceiving it is accom- plished only by means of a telescope : therefore the power of perceiving the ring of Saturn is the result of the telescope. But, would any one continue to maintain a conclusion so glaringly and evidently incorrect ? The tele- scope, here, is the mean through which is de- monstrated, by the act of perception, both the existence of the ring of Saturn in the natural creation, and a power of perceiving it in the animal. So the act of perception, through the 114 organization of the animal, is merely a demon- stration of a perceiving power and some of the physical laws of the material world ; and no proof, or shadow of proof, of the perceiving power being the residt of organization. The same must be evident of the other faculties of the soul. As this doctrine of Materialism has no theo- retical advantage in leading to a knowledge of life, so have its accompanying physiological notions no practical utility in facilitating an understanding of disease, or in leading to an easier or more certain method of cure. But its advocates have thought, that the evident cause of some mental diseases, and the means of relieving them, have much weight in support- ing their system. In the treatment of diseases of the mind, in which this question, so far as disease is concerned, is solely at issue, the only useful measures are those of removing or avoiding the evident causes which destroy, interrupt, or derange the exercise of the animal faculties; but there is no known means of giving or destroying, of increasing or diminish- ing, any faculty. The faculties may as clearly be understood to have a perfect existence, where their exercise is imperfect, deranged, or 115 suspended, as \.\\q faculty of seeing the ring of Saturn may be comprehended to exist in per- fection, althougli the telescope through which it had been viewed be destroyed, broken, or so much impaired, as to be no longer the means of accomplishing the perfect act of perceiving that object. The intellectual faculties are al- ways so immutable in their nature, that wher- ever the organization is perfect through which they are exercised, their acts are always perfect : thus, if the eye and its appendages be of per- fect structure, vision, or the perception of light, with its modifications of colour and form, will always be correct. So of the act of per- ception through other organs. Another mode of argument adopted by many controversialists, and used also by the sup- porters of Materialism, is one not so much calculated to give a direct weight to their own opinions by an appeal to facts, as to afford an indirect support by confounding the doctrine of their opponents. In adopting this method, the advocates of Materialism assert, that the soul, about which men have talked, is a thing of mere negative qualities, not evidenced by any direct testimony of the senses, nor by any indirect proof from its effects. They then I 2 lie demand, where is proof of the mind of the foetus, or of the child just born ? The asser- tions concerning the soul, that it is a thing of negative qualities, &c., is absolutely incorrect. Its qualities are of the most positive and fixed nature of any qualities with which we are ac- quainted ; they are also evidenced to the indi- vidual, both by the direct testimony of all his senses, and by most decisive proof in their effects, as is seen in the acts of perception, memory, volition, and affection. To the ques- tion concerning the mind of the foetus, or the child just born, there attaches all that am- biguity which must result from a vague and unsettled usage of the terms Mind and Soul. In reply, it must be acceded, that the mind, which I have defined to be the acquirements of the soul, is not yet formed, but the anima or soul has as perfect an existence as in the adult, as may be seen by future observation of its development. If the existence of all things which are unseen, unheard, and un- touched, be denied, then must they deny the existence of the power of perceiving the ring of Saturn to those who have not seen it, of hearing the sound called pectoriloquy to those who have not heard it, or of feeling the intense cold of frozen mercury to those who have never touched it. In fact, no power ox faculty is known but as recognized in some act. So that while the Soul's actual being in the foetus is not disproved by those who deny its existence, we are free to admit and acknowledge, that the Mind is acquired, ** that itis infantile in the child, manly in the adult, sick and debilitated in disease, frenzied or melancholy in the mad-man, enfeebled in the decline of life, doting in decrepitude, and annihilated in death." Further, in the spirit of this method of argument, to confound the reasoning of their opponents, they tauntingly demand concerning the nature of immaterial being ; forgetting that, if a similar demand be made of them concerning the nature of matter about which they imagine themselves so much more conversant, they would be unable to define it further than by its qualities, which is no more than may be done, and here- in has been done, of being called immaterial. Another circumstance upon which they have confidently grounded their doctrine, and to which they constantly appeal, and which has stamped upon their system the greatest appear- ance of truth in the eyes of cursory observers, is that of great mental display being accom- panied by large cerebral development. And 118 herein at first view, while the attention is con- fined to man, the monkey, and the fox, observa- tion may appear strongly to favour their opinion; but it is a point by no means so simple and easy of conclusion, as may at first be supposed, when the animal creation is more extensively considered. Of the actual mental acquirements of other animals than man, so little is known, that to make them a subject of philosophical discussion as a matter of amusement, is as much as they admit of; but to make them the basis of a hasty conclusion, upon the truth of which depends the question of all others most important, is more than should be allowed upon their uncertain nature. It is, however, a generally-admitted fact, that man is pre-eminent in the animal creation of this world in mental acquirement, and he is particularly marked by great cerebral development. The monkey tribe has been thought to come nearest him in mental acquirement, and to have a correspond- ing large development of brain. And the fox, marked by his sagacity and scheming wiles, is found also to have considerable cerebral structure. But here the system terminates, and the sagacious horse has relatively but little brain, and the more sagacious elephant, perhaps the. most intellectual of all quadrupeds, has 119 even less than the ass, or than almost any other known animal living in air. Perhaps of all the arguments upon Material- ism, those founded upon the size of the brain will be found, on an extended view, instead of supporting it, to invalidate most that system ; since the fact is not complete, taken universally, that mental development and cerebral develop- ment always coincide, as has been already shown : and it is particularly opposed, taken in an individual species, by the circumstance of the relative size of the brain in the child, or young animal, being much greater than in the adult. Here mental development is certainly least, where cerebral development is greatest. The assertion therefore of a writer on organiza- tion (Sir C. Morgan), that the diminished powers of thought in old age, is attributable to the diminished size of the brain, is not un- questionable as he has supposed. The structure, functions, and economy of the brain appear to me easiest understood, and to have the most useful tendency in explaining the phenomena of life and disease, by regard- ing it as a glandular organ destined for the immediate secretion of electric fluid from the 120 blood after the food has been digested and elaborated by the assimilative functions. This opinion of its nature and office is supported by its glandular appearance, by its being supplied like glands by a much greater quantity of blood than can be supposed necessary for its support (about one fifth of the whole circulating fluid), and by the tortuous dispensation of its vessels before entering its substance. View^ing it thus, in connexion with the assimilative functions, we can more readily comprehend those cere- bral disturbances which we see hourly arise from disturbance of the digestive organs, than by any hypothesis at present received. On the admission of this opinion, its varied size becomes perfectly intelligible, whether regarded in the individual species, or in the animal creation generally, as I shall proceed to show. First, let us treat of man in the general order of animal beings ; and, afterwards, of him in his individual species. He has a greater relative proportion of brain than any animal of his size, because he requires greater elaboration of electric fluid. The two great properties of animal matter dependent upon this fluid for their support, are sensibility and muscular contractility. The required quantity of electric 121 fluid for the support of the first property in an individual, is determined by the number of sentient organs, by the size of the animal, and by the nature of the medium in which it is destined to live : the quantity of electric fluid required for the support of the second property, will be determined by the degree of muscular contractility required by the animal. Man, having as many sentient organs as any being we are acquainted with, and living also in the rare medium of air, will have occasion, therefore, for as great a supply of electric fluid to support his sensibility, as any animal of his size. But he diflers from all other animals in having an erect form, to the support of which is required amazing muscular exertion. The act of standing in quadrupeds, is nearly mechanical, or accord- to the laws of inert matter; but the erect attitude of man, from the mechanical construc- tion of his skeleton, could only be eff'ected by a constant exertion of muscular action. Hence we see, that, without being capable of exerting any great physical force, compared with many other animals of his size, he is relatively the most muscular being in the serial creation ; especially in the form of his legs, thighs, buttocks, and loins. In the female of his species, this relative development of muscle in the legs. 122 thighs, &c., is further increased, to enable her to support the incumbent weight of her uterus when gravid. The loss of physical power in maintaining an erect position, may be easily conceived, when the attention is directed to the circumstances, that in the upright position, one more powerful man can restrain another, but in the recumbent position, it requires several persons to restrain another, because that muscular action which had been required to keep the body erect, is, in the recumbent position, left free for resistance ; hence those seemingly wonderful muscular exertions, which are seen in epilepsy, mania, intoxication, and in rows, where one is thrown down and exerts himself on the earth. In taking a captive, he should always be kept upon his legs. To the support of this muscular exertion, so necessary to the erect form, a much greater supply of electric fluid will be required, than in the profie position of quadrupeds. All erect animals will therefore require a greater development of the organs by which that fluid is elaborated and secreted, than other living beings : hence the abdominal development of man, is relatively greater than any other omnivorous animal, and his cerebral development relatively larger than any other living being of his size. The child, 123 from its size, having occasion for a relatively greater quantity of electric fluid to support its sensibility than the adult, will have still greater relative abdominal and cerebral development. The increasing size of the animal from infancy to manhood, is accompanied with a gradual diminution of abdominal and cerebral develop- ment ; hence in man as a species, the greatest relative cerebral development is in the smallest animal. Dwarfs, as a general rule, are large- headed. And I believe, there is never much muscular development accompanying the idiotic head. The monkey tribe are quadruped, but their great cerebral development may entitle them to a separate consideration ; they are very agile, and differ from other quadrupeds in being able to maintain for a considerable period an erect po- sition, and of performing many actions with their then upper extremities, imitative of man. Their great muscular power, and their diminished size compared with man, will account for their great cerebral development. Throughout the whole of the ape tribe, the relative size of the brain is greatest in the smallest animal, and is least of all in the great baboon. An exception to this rule is found in monkies having prehen- 124 sile tails ; to this power is required a consider- able super-addition of muscular energy, and hence they surpass their fellows in largeness of brain, and the smaller of these animals equal man. The prone position of quadrupeds, and the mechanical manner in which they are sustained upon four supports, renders necessary to them a much less muscular power than is required by man ; and nearly the whole of their muscular energy may be used in physical force, very little being required to sustain their position : they have therefore, equal or superior strength with much less cerebral development than man. Throughout this order of animals, the relative size of the brain by no means corresponds with the apparent intellect ; but, as a general rule,, with few exceptions which may be easily explained, the relative size of the brain is greatest in the smallest, and least in the largest; being largest in the little field-mouse (equalling man), and gradually diminishing through the increasing size of quadrupeds, up to the largest. I know not whether there be in existence the skull ofa mammoth, but if there be, I will venture to assert, that it has less relative capacity for brain than any other air-breathing quadruped. 125 The exceptions to this general rule in quad- rupeds as an order, are found in animals of an inactive nature, as the hog and ox. The horse is also an exception ; he, although strong and swift, is incapable of long-continued muscular exertion. In any species of quadruped, the rule is perfect. The ass, compared with the horse, has double or treble the relative propor- tion of brain, yet shews no sign of superior intellect : and the relative proportion of brain in the calf, is three or four times as much as in the full-grown ox. Small mice have relatively twice as much brain as rats, and the rabbit has nearly twice as much as the hare. The scull of that well-known horse Eclipse, had an unusual capacity for brain, and he presented, when living, amost unusual example of muscular development; but I am not aware that he evinced any peculiar superiority of intellect to other horses. In birds, the same thing may be observed, the relative size of the brain being greatest in the smallest animals ; and in some very small birds, it does equal and far surpass in relative proportion, the brain of man. The little hum- ming bird, when stripped of its feathers, is nearly all head. An exception to this rule 126 presents in aquatic birds ; the relative propor- tion of brain being in them much less than in land-birds of the same size, as for instance, in the duck and the cock, the eagle and the goose ; this is by reason of aquatic birds having occasion for much less muscular action in loco- motion than land-animals, they have conse- quently less demand for electric secretion, and the organ destined for that purpose will necessarily be smaller. The mechanical position of these bipeds is very different from that of man, the trunk being nearly equipoised upon two supports, requires but little muscular power to preserve its balance, compared with that required for the peculiar construction of the human skeleton. Fishes and reptiles have even much less cerebral development than quadrupeds. Here must be recalled to mind the low degree of sensibility required by animals dwelling in the dense medium of water, and the reason of their low degree of cerebral development will then be clear enough. Among amphibious animals, those, whose more natural element is the dense medium of water, have least cerebral develop- ment ; the brain of the turtle is therefore relatively smaller than that of the tortoise. In 127 these animals, with few exceptions, the greatest cerebral development is in the smallest creatures. Cerebral development, therefore, instead of being in proportion to mental development, is always in proportion to the required quantity or degree of sensibility and muscular contrac- tility, and the brain may be as much and as clearly considered a physical organ, as the liver, spleen, or stomach : but it keeps no proportion with the intellect of the animal, and therefore is not a valid argument to the support of Materialism. Seeing, then, that the doctrine of Materialism is totally incompetent to shew that percepti- bility and the other animal faculties depend upon and arise from organization — that M. Bichat's hypothesis of animal and organic sensibility is sophistical — that the doctrine, with its accompanying physiology, has too many discrepancies to afford a rational basis for practical medicine — that the mind is better understood in opposition to that doctrine— that the anima or soul may, contrary to the opinion of the supporters of that doctrine, be defined, and that as clearly as any other thing in exist- ence—that the opinions advanced concerning 128 the brain do give no support, but on the con- trary, are in direct opposition, to the doctrine — • lean hardly be deemed hasty in concluding, that that doctrine cannot be true upon the reasons hitherto advanced by its intelligent supporters. Seeing also, that, by assuming the independ- ent existence of certain faculties, to which, when considered collectively, may be appropriated the term anima or soul, and, by regarding the body as the mere machine or instrument by which such faculties are brought into relation, or within the influence of the laws of the material world, the whole operations, structure, and phenomena of the animal, become clear and intelligible, not incumbered and opposed by embarrassing discrepancies, but keeping an intelligible uniformity throughout all animal nature as far as it is known; and, that such views aiFord a scientific basis for practical medicine, at once simple and useful, this doctrine may, and ought, philosophically, and setting aside moral and religious considerations, to supersede and take place of any other not possessing these advantages. Life, then, or that state of existence which man possesses in common with his fellow- 129 inhabitants of this world of matter, being best comprehended by regarding it as constituted of a relation between certain intellectual facul- ties or soul, and the physical laws of this ma- terial abode, it follows, as a natural conse- quence, that we regard Death as a loss or destruction of such relation, without any admis- sion of the destruction of those faculties of which our idea of soul is formed. It then becomes a subject of inquiry, both important and interesting, whether certain opinions or notions among mankind of a future state of being, be compatible, or at direct variance, with our physical knowledge. This is soon determined without argument, as it carries with it immediate reasonable assent, that cer- tain faculties which here are placed in relation with the laws of a material world, may, or can hereafter, be again placed in relation with the laws of some other (it is to be hoped happy) abode, and that by the mediate agency of a body. But these philosophical views by no means determine that such will be the case. Philosophically, therefore, the thing is possi- ble, but without any assurance, certainty, or reasonable ground for believing or disbelieving that it will or will not be re-instated in relation with the laws of another world. Nor do I know K 130 of any physical reasons which do in any man- ner support or oppose either view, or indeed, which have any connection with the matter. Any one, therefore, having a belief in a future state of existence, unless he perceives some connection which I do not, must ground such belief on some other support than his physio- logical knowledge, which, while it demonstrates that such an existence may be, goes not one step further to prove that it will be. Many attempts have been made by philoso- phers in different ages, to prove the undying- ness or immortality of the soul. The natural world, however, affords no facts, experience no precepts, profane history no record, and philosophy no reasons, to support such con- clusion. So, that, wherever a belief in future existence has been warrantably held by man- kind, it has not been upon any rational system framed out of philosophy, but solely upon the assurance of some individual, upon whose un- erring veracity, and unquestionable authority, they have had sufficient confidence to rely ; and this confidence in such person has been called Faith ; and whoever wishes to show reasonable grounds for his faith, must do it by an appeal to, and proof of, the character and 131 authority of the individual in whom is his faith. Yet the reasonableness of his belief is much strengthened by showing its accordance with the economy of nature. By nature, I mean the works of God. To conclude : there is between this system of physiology and the doctrine of Christianity, so far as regards a future life, a remarkable and beautiful accordance; which, while it affords a reflective brightness of truth upon both sys- tems, breaks down and destroys that barrier which has hitherto existed between science and religion. And the doctrine of a resurrec- tion, and that strictly and literally as taught by Jesus the Christ and Paul his apostle, may now as reasonably be held in accordance with the laws of science, and maintained by genuine and unsophisticated reasoning, as any opinion I know of. And it is remarkable that the doctrine of the resurrection, as taught by Christ and his apostle, is the only doctrine of the resurrection which can be reasonably and philosophically maintained. Philosophy is capable of showing, and it has been herein shown, that a future state of ex- istence maybe — Jesus the Christ has declared K 2 132 that it will be — and Paul, his apostle, has de- clared how it will he, when in speaking of the resurrection, and seeing the difficulties by which it might be surrounded in the minds of ob- servant and reasoning men, he anticipated the question which probably did then, and has since, so much puzzled philosophers with their erroneous system of physiology to answer : "Some men," observes he, ** will say, how are the dead raised up, and with what body do they come ?" This is evidently in allusion to the organic destruction of the animal, but he replies, " Thou sowest not the body which shall be ;" he then indulges in a figure of speech, and resumes thus, *' but God giveth it (the person, the anima or soul), a body as it pleaseth Him." CHAPTER X. To admit a Soul in all living creatures is not un^ scriptural — Cojnparisoti of the brute and human Soul — ivherein they differ — Language — acquired before knoivledge — uses of this — The act of abstract- ing, explained — is essential to religious knoivledge — irhy religion cannot he acquired by brutes — On the minds of savages — Conclusion. In the Scriptures, mention is made of " the spirit of man which ascendeth upwards, and the spirit of beasts which goeth downwards to the earth." The phrase also occurs, " in whose hands is the soul of every living thing." Beside which, there are several instances where the term Soul might be applied in speaking of other creatures than man, in which the trans- lators have substituted the word Life : so that the admission of an Anima throughout the whole living world is not more philosophical than scriptural. But, as so much greater value is set upon the soul of the human race than upon the brute kingdom, both in man's esti- 134 mation (in which I am willing to admit he might be misled by pride and an undue self- consequence), and also by God, as is believed by those who admit a revelation from Him, it becomes a matter of interest to inquire wherein the soul of the one differs from the soul of the other, and to seek whether that vast difference does exist between them which has been generally supposed; and whether those views which religion unfolds of the designs of God towards man, and his hopes of a future existence, are consistent with phi- losophical truth, and whether philosophically they are peculiarly his. The powers of perceiving, retaining, com- paring, and discerning the nature and qualities of physical bodies, are quite equal, if not supe- rior, in the brute kingdom. The eye of the hawk, pigeon, cat, spider, trout, and, indeed, of most brute animals, is quite equal in quickness and power to the eye of the human race. The sense of, and discernment by, smell, in flies, birds, some dogs, and probably in many other animals, is astonishingly beyond that faculty in man. The senses also of hearing, touch, and taste, we have no reason to consider in them inferior to man. Their power of retaining is, in many 135 instances, strongly exemplified in the remem- brance of a master by dogs, where his memory had faded from his human friends ; and the memory of particular spots for building and breeding by birds and fishes, are striking ex- amples of this faculty in the brute kingdom. To a certain degree of physical compounding, the brute creation are also equal, as in the dancing of dogs, horses, &c. The acts of voli- tion are also as perfect in them as in man. They afford also proof of their capacity for sensual passion, and many instances of the strongest affection for a sensible object, so strong indeed, as to have their death caused by its removal. But in the highest of the intellectual faculties, I mean the faculty of abstracting, they appear totally deficient ; it has no existence in any other animal than man, and hence, from the exercise of this faculty in him, may be traced all his intellectual supe- riority ; and this faculty gives him also a ca- pacity for religion and its hopes. No one has ever been able to define the exact line between reason and instinct, nor does there in fact exist any such distinction in nature: all animals reason, but not equally, and the human race, by the super-addition of a faculty above other animals, arc enabled to reason so considerably beyond all 136 others, as to render by comparison the brute powers of reasoning hardly worthy of the name. Man, before the exercise of his higher faculty of abstracting, differs nothing in his reasoning from the brute creation ; the infant in discern- ing pleasure from pain, bitters from sweets, and in discriminating its parent, does not at all excel the faculties of the brute world ; nor in its cries and smiles does it at all surpass the cries and playfulness of other animals, as signs of its pleasures and pains. Language, according to the opinion of Mr. Locke, originated, and the nature of the thing proves that it must have originated, upon the basis of abstraction, because, M'ith the excep- tion of proper names, and a few other terms indicative of the commonest actions of life, nearly all terms in language are but signs of abstract ideas. Yet before the exercise of the faculty of abstracting, we see children taught to articulate words, and to comprehend them as signs or representations of things : and at a later period, before the exercise of the faculty of abstracting commences, we may see the extended vocabulary of preceding ages (the result of centuries of abstractions) learned by 137 rote. This education of words without know- ledge is yet highly useful, and answers three important ends : First, it becomes an index and incitement to actual knowledge : Secondly, it facilitates an application of terms to know- ledge when afterwards acquired by abstraction ; and. Thirdly, it keeps an uniformity of language, by the same terms being used to denote the same abstract ideas when acquired. It is difficult to say at what age the faculty of abstracting commences, but I do not think it is often exercised in any great degree before the age of fourteen (I am now speaking vaguely) ; but, until it does commence, however much the human subject may differ from the brute crea- tion in form, or in its superior power of execu- ting a device, or in its application of sounds as images or signs of things (a result of education), it has no superiority of actual intellectual knowledge. It may have all the outward figure, actions, and denotements of knowledge, without its existence ; as the player may have all the signs, actions, and exterior workings of jealousy, without the inward feeling or actual knowledge of that passion. This is one of the greatest evils of juvenile education, that it gives the appearance of knowledge without the spirit of it, and hence the almost universal appear- 138 ance of knowledge in this highly-educated age. In the act of abstracting, the soul contem- plates a quality away from the being in which it exists ; and, having contemplated the same quality away from several beings in which it had existed, the soul regards that quality in a general view : hence it becomes a general abstracted idea, and is indicated by one general term as white, hard, fluid, &c. So may be contemplated, abstractedly from the object in which it had existed, goodness, beauty, power, truth, &c. &c. Where the faculty of abstracting has no existence (as in brutes), or where it is not exercised (as in children), those qualities can only be contemplated in their union with the being in which they are perceived, and conse- quently the structure of their minds is nearly similar, although the child by the acquirement of a language has seemingly so great a supe- riority. The brute, being incapable of general abstractions, can never have terms to indicate abstractions ; and the terms which the child has acquired are not signs to him of general abstractions, but merely signs of sensible 139 qualities ; although, afterwards, if he come to abstract, those terms will then be used by him as signs of his abstractions. The first point of Religion is the comprehen- sion, admission, and belief of the existence of God. This is a knowledge which cannot be attained by means of those faculties which are common to the brute creation as well as man. It is upon sensible objects only, their faculties can be exercised ; but God being immaterial, and therefore not subject to sense, cannot be comprehended, perceived, or attained to by them. Nor is He comprehended, perceived, or attained to by man, although his name may be used, and his attributes familiarly discoursed of by man, until the higher faculty of abstracting comes to be exercised. Until then. His name, and the name of his attributes, are mere signs, acquired by rote, of things not comprehended, in the same manner as a child uses the term world, without any definite idea of its form, structure, size, or any of the qualities which make up the definite idea connected with that word : in the same way, children will talk of death, angels, heaven, &c. &c., without any definite ideas. But when the soul of man comes to exercise its faculty of abstracting, then it 140 attains to the comprehension of the existence of Power, independent of, or away from Matter, and may be led to the admission or belief of the actual existence of such independent or distinct power. So an idea of justness may be acquired abstractedly from any being in whom we have traced some faint lines of it. And if the soul now, by an act of compounding, considers these two qualities in their fullest and most perfect existence as forming attributes of one being, we come to a limited conception of God. By adding to these ideas the abstract ideas of truth, mercy, goodness, love, omniscience, omni- presence, and eternal existence, we come to a compound conception, of which the word God is the sign in language. But of a full, extended, and perfect knowledge of God, it cannot enter into the heart of man to conceive. This con- ception of God is not necessarily connected with a belief in his actual existence, for the soul may by abstraction attain to the concep- tion of all these qualities or attributes, and yet perceive no just reason for believing in their actual existence, any more than an abstract conception of a less perfect character would necessarily enforce a belief in its actual exist- ence. So that, although the power of abstract- ing is essential to a conception and philosophical 141 belief of God, and animals that have it not can- not consequently attain to that knowledge, yet it does not follow, that all who possess a faculty of abstracting must necessarily conceive of and believe in Him. The nature of Religion,presupposing a Supreme Being, holds out also a promise of future exist- ence. Of this Supreme Being, as distinct from matter, I have already shown that brute animals, because they abstract not, cannot conceive ; and upon the same ground may be argued their inability even to conceive of a future renewal of their being. They are, in fact, entirely confined to sensual knowledge, and their reasoning goes no further than upon the immediate objects of sense, their wanting of the power of abstracting bounding their knowledge. Nor are the brute creation adapted for a com- pliance with the dictates of religion, which not only inculcates continually a restraint of sensual conduct, but often imposes a behaviour diametrically opposed to sensual interest ; and it enforces, above all other commands, an affectionate obedience and unswerving servitude to the Supreme Will, things of which the brute faculties cannot even conceive. Now, if from the highest instance of intellectual culture in 142 man, be taken away from him that knowledge which had been acquired by the abstractions of preceding generations, of which the signs were communicated to him from the parent generation by language ; and also those abstrac- tions which he himself has made ; and also his combinations or compoundings of abstracted ideas ; you reduce him at once to the low ebb of brute reasoning, and cut off from him all the attainments which dignify his nature, as language, imagination, verbal and intellectual composition, intellectual affection, science, and religion. Where the intellectual acquirements of the parent generation of the human race are very limited, there is accompanying a correspondent poverty of language, and the vocabulary of these people is little more than a collection of proper names with a few terms indicative of the com- monest actions of life. Here the offspring generation receive not even the lingual signs of knowledge from the parent, and consequently go on from generation to generation in an ignorance very little inferior to the brute part of the creation, as may be seen in the untutored natives of Africa, and the savages of other parts. Among these people, as among the brute world, 143 may often be seen considerable dexterity in art, and nearly always great natural powers of sense ; but of science and intellectual acquirement there are found but very faint traces. This is not from the faculty of abstracting being defective in these men, but from its remaining unexercised. If language be introduced among these at present ignorant and barbarous people, by another generation of mankind, who will also explain the meaning of the terms comprised in that language, then these hitherto apparently brutal creatures, by exercising their dormant faculty of abstracting, attain to as clear and perfect knowledge of the sciences and of religion, and emerge into characters as highly intellectual as the benevolent generation who took the first step towards dignifying their nature. In this instance, as I have before observed, language is not knowledge, but merely an index or light towards it. There does appear then, a vast difference between the anima or soul of man, and the anima or soul of brutes, and it becomes evident, that the soul of man is naturally and philosophically and peculiarly adapted for those higher contemplations and sublime hopes which Religion upholds to his race. And with- 144 out entering into the designs of God towards the other parts of the living creation, upon which philosophy and revealed knowledge afford so little light, both teaching merely that He is not unmindful of them, it behoves us gratefully to receive, studiously to contemplate, and heartily to comply with those dictates which are essential to the advancement of His gracious designs towards us. FTNIf, T. C. Hansard, Pateinoster-row Press- 14 DAY USE RETURN TO DESK FROM WHICH BORROWED BIOLOGY LIBRARY TEL. KO. 642-2532 This book is due on the last date stamped below, or on the date to which renewed. Renewed books are subject to immediate recalL DEC 10 1973 PETUR.NED TO ''•^'^2S 73 2 ClOLOOY LIBRARY LiD21A-6Tn-9,'73 General Library ( R2491610 ) 476-A-32 University of California Berkeley vn A LA MfiME LIBRAIRIE : Ualadies dii systtjme iierveux. Lecons professees k la Faculle de raedeciiie de I'aris, par le pi'ofe«.