MEDICAL LITERATURE.
Article XII.—Retrospective Review.—Tractatus de Ventriculo et Intestinis, cui prœmittitur alius, de Partibus continentibus in Genere, et in Specie de iis Abdominis. Authore Francisco Glissonio, &c. &c. Lond. 1677, 4to.
As it is not our intention to confine our remarks to the work above mentioned, we shall deem no apology necessary for the somewhat excursive nature of this article, which would not answer our present purpose, if we were obliged to follow the costive details of the venerable Francis Glisson, whose villanous bad style, and execrable latin, are only to be excused or overlooked in consideration of the great importance of the topics which he handles, and the profound reflections which he makes on them. Glisson is recognised as author of the physiological term Irritability, and as the assertor of the inherent activity of matter. Haller says of him in his XIth book. "Franciscus Glisson, qui universis elementis corporum, vim motricem tribuit, etiam nostram vim, Irritabilitatem vocavit," &c.
He was a native of Dorsetshire, and was appointed professor of physic at Oxford in 1627. This post he occupied during forty years, and is much distinguished by his treatise de vita naturæ, and by the work which forms our caption. As he is the first who used the physiological term irritability, we have thought that some researches on this subject in general, and more particularly on his peculiar sentiments, might profitably occupy our retrospective department; for it is very evident that this subject is in general but vaguely discussed, both in medical writings and conversation.
The ancient philosophers did not agree among themselves as to the nature and origin of matter; some of them considering it as eternal in its essence, and others as mutable and changeable in form. The theory of atoms, published by Democritus, and subsequently carried out so elaborately by Epicurus and his disciples, seems to have reached even to our own times, with an increasing reputation and acceptance. According to this theory, the kinds of matter, or elements, must he regarded as infinitely various. Heraclitus, who taught philosophy about 550 years before Christ, considered all things as derived from an elemental heat or fire;[25] a philosophy which seems to us to have formed the basis of the Hippocratic doctrines of life. Like Heraclitus, Hippocrates tells us, that the calidum was the first principle of things, and that by an expansion or extension of itself, it constitutes all the objects of the material world. He expresses himself in the following manner. That which we call warmth, or heat, seems to me to be something immortal; something which comprehends all things, which sees and knows all things, as well present as future. Thus assuming as a basis, that the calidum is an almighty, all-wise being, or in other words, a God, all in all, the cosmogony was developed as follows: Chaos he regarded as that condition of the calidum, which preceded any exertion of the Almighty faculties. In emerging from the chaotic state, the greatest part of the heat having assumed the uppermost place, formed the æther; another part having gained the lowermost place, constituted earth; a third portion, midway between earth and æther, became air; and a fourth part, establishing itself between the two latter, became water. So that by means of the extension of this all-wise, elemental calidum, we have the four elements, earth, air, fire, and water, out of which are ultimately composed all the aggregates of the material world.[26] Now, to apply this general principle to the formation of the living being man, who seems to be a sort of microcosm in himself, we are told, that that portion of heat which remained with earth, being expanded and spread abroad in divers places, in some more, in others less, the earth became dry, and something like membrane or pellicle was formed; the matters contained in which, being heated as by a sort of putrefaction, some parts became bone, some nerve, some veins and their contents, and some formed the cavities and their contents, as the urinary bladder, for example.[27]
The full exposition of the opinions of Hippocrates was left for Galen, and we prefer to make reference to him on this theory, which by his genius and talent was so much embellished, that it became the glory of science, exercising an almost undisputed authority during a long lapse of ages. Indeed the gigantic intellect of this great man, still continues to shed its vast illumination over the world of science, particularly that of medicine; which, if it owes its birth to the divine old man of Cos, is not less indebted for its nurture and growth to the celebrated native of Pergamus. Galen is the facile princeps of physicians. His astonishing industry, perseverance, and acquirements, his ingenious arguments, and persuasive eloquence, give him an unquestionable claim to the title of princeps, so long accorded to him; and those who even in the present enlightened period, will study his works, shall find themselves almost irresistibly led away by the charm of his suasion.
Galien est le seul des anciens qui ait donné un corps complet de medecine: Quoique formé des débris de toutes les doctrines précédentes, son systeme offre cependant, malgré les contradictions ou il tombe assez souvent, une unité remarquable dans toutes ses parties; un ensemble séduisant, qu'un genie de l'ordre le plus élevé pouvoit seul imprimer à un pareil édifice. Ramenant tout à un petit nombre de principes généraux, qui s'ils ne peuvent satisfaire la raison, fournissent du moins une réponse facile a tout, ce systême dut être adopté avec empressement, et sa fortune ne peut étonner.—Biographie Medicale, Tom. IV.
Galen may perhaps be justly regarded as an eclectic; but it is manifest, that he mainly walked after the steps of his great predecessor, and recognised model. The following passage seems to contain ideas not much differing from those of Hippocrates which we have presented above: "Who is there, says he, that judging from the origin and constitution of animated beings, doth not immediately infer the existence of a mind, possessed of wonderful energies, extending to, and pervading every portion of the universe! We every where perceive animals procreated, which are possessed of the most admirable structure, and yet what portion of the universe can be more ignoble than this earth of ours? Yet a grand intelligence is seen to have reached even it from the celestial bodies, which for their beauty are so astonishing, and which, as they are for purity far more excellent than our earth, so they are the seats of intelligences, far more pure and perfect than those which inhabit these lower regions." He proceeds to remark, that animals, worthy of the greatest admiration, are produced out of the slime and mud of ponds and ditches, and even in putrefying vegetables, which, as they indicate the miraculous properties of their author, also show us in what estimation we should hold the higher orders of being. "We may even perceive a rational nature in men, if we refer to such examples as Plato, Aristotle, Hipparchus, Archimedes, and many others. If, therefore, in such a colluvies as the human body, (for by what better name can we characterize a mixture of blood, bile, and phlegm,) a mind is formed of such great and excellent faculties, what must we think of the excellence of that which exists in the superior bodies?"
It may be said that Galen expresses, in these passages, the Platonic dogma of an anima mundi. But they certainly agree with the sentiments of Hippocrates; and whether he derived them from the former or the latter, matters not, as both of them have invested matter with certain qualities, which render it active, whether it be so essentially or by the act of the Creator. Galen may be also regarded as partially an Epicurean; for he insists that there are several sorts of matter, or as we should say, several elements; but he differs from that sect again in affirming for it a passible quality. To show that there must be more than one element, or kind of matter, he says, that if there was only one element, or a unit, it would be impassible; it could undergo no change whatever. For there would be nothing by which it could be made to suffer any alteration, or into which it could be altered. Whatever is changed, is changed into something else, and whatever suffers, suffers from something extrinsic: therefore he affirms, that of necessity there must be several sorts of matter, or elements. He says, "there are only two theories on this subject deserving our attention; one of which affirms that sentient bodies are composed of elements possessing the faculty, (cum patiendi tum sentiendi,) both of suffering and perceiving an alteration;" while the other affirms that such bodies are formed (ex patibilibus, sed sensu expertibus) out of passible, but not sentient elements. Neither of these doctrines does he consider tenable, so long as only one element is affirmed, as earth, air, or fire alone, which could never become capable of that great variety of actions we witness in living bodies: but, admit several elements, and we suppose that the mutual interchange of powers would yield a compound body, capable of all the vital phenomena. Such, therefore, says he, as consider the human body to be composed of fire, air, earth, and water, mutually transmuted, alternated, and reduced to a given temperament, and thereby vested with a sentient faculty, speak reasonably; and it is evident that there must be more than one element, and that these elements are passible bodies.
Plato had taught, that, though all bodies are formed of matter, yet matter itself is not a body; and the same idea is conveyed by Aristotle, in the Lib. de partibus animal. & earum causis, II c.i. "Prima statui potest ea quæ ex primordiis conficitur, iis quæ nonnulli elementa appellant terram dico, aquam aërem & ignem: sed melius fortasse dici potest ex virtutibus confici elementorum, iisque non omnibus sed ut ante expositum est humiditus enim, & siccitas, & caliditas, and frigiditas, materia sunt corporum compositorum."
Galen also states, that in fire there exists a perfect heat and dryness, in earth a perfect coldness and dryness, and so on of the rest of the elements. For you cannot expect to find in nature a perfectly simple and isolated element; because they are always mixed two or more together. Hence the real terram, aquam, aërem, and ignem, become rather a metaphysical abstraction, than a real entity. That is to say, matter has no real existence, but is mere quality; for earth is not the mere representation of dry or siccum; it is the representative of siccitas, or dryness: fire is not the eidolon of calidum, but of caliditas; water of humiditas, and air of frigiditas. Yet all these elements are in nature possessed of more than one property. Fire is hot and dry, earth is dry and cold, water is cold and moist, &c. If we refer, however, to his account of the soul, we perceive at once, that these inseparable qualities of the elements are the real active agents of life. He plainly declares, that the soul is the mere result of organization, and perishes with the structure in which it dwells. He thinks, "corporis temperiem censendum est." As to the active powers of the four primary qualities, he says, "At mihi quidem tam venæ, quam reliquarum particularum singulæ, ob certam quandam temperiem quam ex quatuor sunt qualitatibus nactæ, hoc vel illo modo videntur agere."—De nat. fac. I.
It is plain he thinks, that the elements consist of a materia and qualitas; but they are elemental by the qualitas and not by the materia.
After establishing that there are four elements, which are the common and simple bases of all things, he goes on to show, that the proper proportion and admixture of these, constitute the healthy state of living bodies. If the calidum, for example, be unduly increased, the body is destroyed; if it be improperly diminished by excess of the frigidum, it will also perish. The business of the physician is to keep the proportions just and harmonious; but, as no pure element exists alone, the physician must employ the qualitas in conjunction with the materia. These (to make a phrase) substantive qualities, are found in medicines or food, which, like all objects of sense, are either cold, hot, dry, or moist, and available of course in the management of a cold, hot, dry, or moist derangement of the living body.
The elements of the human body exist in the four humours, blood, bile, atrabilis and pituita; and these four humours correspond in quality with the elements. Blood, which is the reservoir or continent of them all, is a temperate humour. Bile, being the representative of calidum, is hot and dry. Melancholy represents, in our microcosm, the element earth or siccum, and is dry and cold. But pituita, which is moist and cold, corresponds with the humidum element. Air exists in animals nearly pure, as we learn from the phenomena of the pulse and of respiration. It answers to frigidum.
He shows us in his lib. de naturalib. facultat. that, out of the humours, all the parts are formed, and these parts are either similar or dissimilar; i. e. simple or compound. Bone is a similar part, that is, it is a simple part; so is an artery, or vein, or ligament. Each of these is so constituted, as that it has a predominance of one element in its nature; and it is therefore dry, or cold, or moist, &c. But if an adust element be, by accident or disease, accumulated in a part naturally cold, the function of such part is morbidly affected. The natural tendency, however, of similar humours to unite, causes each part to receive its regular supply; a principle which Bichat has since characterized as, contractilité organique insensible.
To show the wonderful simplicity of the Galenical system, which for plainness and easy attainment may be compared with the improved nomenclature of chemistry, we will cite a passage from Argenterius, who, perhaps, was as learned in this kind of lore as any man of his time. In his Tractatio de calidi significationibus, he says; "If any body would undertake to give a general enumeration of those circumstances, in which this term calidum and the others (frigidum, humidum, &c.) are applicable to the explanation of this warmth, he shall find truly, that they are the elements, the humours, the parts, the whole body, medicines, food, air, climate, the weather, the season of the year, and even ages; for these all are either temperate, or hot, or cold, or humid, or dry."
The animal body is moved and governed by two principles; one of them corresponds to the vie animale of Bichat, and the other to the vie organique. Since the power of sensation and of voluntary or elective motion, says he, is a property of animals, and since that of growth and nutrition is common both to animals and plants; the former may be called attributes of the soul, and the latter attributes of nature. Whence we say, that animals are governed by the soul and by nature, while plants are governed by nature alone.
The powers of the body are faculties; and these are either natural, vital, or animal: but they are so subdivided, that we have as many faculties as there are sorts of action. Under the class of natural faculties, we find three principal sorts; to wit, a facultas generatrix, an auctrix, and a nutrix. But if you ask, says Galen, how many faculties there be, which result from the action of these on each other, you will find them as numerous and diverse as there are numbers and diversities of the animal parts. For example, we have an attractrix faculty, a retentrix, alteratrix, expultrix, &c. &c., all of which are variously modified, according to the nature of the similar or dissimilar parts they are exercised in, or, in other words, according to the nature of the tissues or organs, in which they reside.
Need we go further to show, that Galen, believing all matter essentially conjoined with the hypothetical caliditas, frigiditas, &c. &c., taught that it was gifted with such a degree of inherent activity, as to render it capable under certain states of combination, of exhibiting all the phenomena of organic and animal life? It is certain that he regarded these active qualities, as the causes of all the phenomena, whether of living or dead matter.—Glisson ought not certainly then to be regarded as the author of this dogma in medical philosophy. Plato certainly taught it. Van Helmont could not get along without investing matter with what he called a "seminal likeness, which is the more inward spiritual kernel of the seed," &c. But we will let him speak for himself. "Whatsoever," says V. H., "cometh into the world, must needs have the beginning of its motions, the stirrer up and inward director of generation. Therefore all things, however hard and thick they are, yet before that their soundness, they inclose in themselves an air, which representeth the inward future generation to the seed in this respect fruitful, and accompanies the thing generated, even to the end of the stage: which air, although it be in some things more plentiful, yet, in vegetables it is pressed together in the show of a juice, as also in metals it is thickened with a most thick homogeniety or sameliness of kind. Notwithstanding this gift hath happened to all things, which is called archeus, or chief workman, containing the fruitfulness of generations or seeds, as it were the internal efficient cause; I say that workman hath the likeness of the thing generated, unto the beginning whereof, he composeth the appointments of things to be done. But the chief workman consists of the conjoining of the vital air, as of the matter, with the seminal likeness, which is the more outward spiritual kernel, containing the fruitfulness of the seed; but the visible seed is only the husk of this. This image of the master workman, issuing out of the first shape or idea of its predecessor, or snatching the same to itself out of the cup or bosom of outward things, is not a certain dead image, but made famous by a full knowledge, and adorned with necessary powers of things to be done in its appointment; and so it is the first or chief instrument of life and feeling. But since every corporeal act is limited into a body, hence it comes to pass, that the archeus, the workman and governor of generations, doth clothe himself presently with a bodily clothing. For in things soulified, he walketh thorow all the dens and retiring places of his seed, and begins to transform the matter according to the perfect act of his own image; for here he placeth the heart, but there appointeth the brain, and he every where limiteth an unmoveable chief dweller, out of his whole monarchy, according to the bounds of requirance of the parts and appointments. At length that president remaineth the overseer and inward ruler of the bounds, even until death; but the other, floating about and being assigned to no member, keeps the oversight over the particular pilots of the members, being clear and never at rest or keeping holiday."
Notwithstanding the affected and euphuistic jargon of the above passages, it is evident that Van Helmont's idea is very similar to that of Galen. By seminal likeness, we are to understand an aptitude in matter to take on certain determinate forms, and this may be supposed to differ not very essentially from those laws, which govern matter in crystallization. But even this seminal likeness, as we perceive, is a sort of abstraction, very analogous to the Galenical caliditas; for it is the more inward spiritual kernel of the seed, whereby the matter is enabled to enjoy a certain degree of activity, the degree of which is much increased by the union of the air, or archeus, with it. So the caliditas of Galen, which, after all, is matter, gives to its subject the powers which it enjoys. Glisson, speaking of the natura seminalis, says that it is a certain or specific essence, superadded to mere elementary principles, by means of which mixt bodies adopt certain determinate forms, and acquire the faculty of performing essential operations, more noble than those which belong to naked elements.
We regret very much that we have been unable to procure a copy of Glisson's treatise de vita naturæ, which, so far as we know, can not be had in this country. We shall, therefore, furnish our readers with the following passage from the Biographie Medicale, from the pen of Jourdain.
"The name of Glisson occupies an honourable place in the history of medicine, because to him we are indebted for the first elements of the physiological doctrine of the present day. Instead of directing his attention to movements alone, as the iatro-mathematicians, and even, to a certain extent, the animists had done, he referred to vitality all the phenomena of nature, of whatever kind, and attempted to reduce them to one, common principle. To this end he admitted, that matter is originally endued with forces inherent in it, and that living bodies in particular, are invested in their organs with a radical force, which, put in play by stimulants, whether internal or external, gives rise to all the phenomena of life. He even went so far as to assert, that sympathy may be explained by referring to the intercommunication of this force, to which he gave the name of irritability."
We shall also cite from Sprengel, a passage which throws some light on his theory.
"When they became unwilling, like Descartes and Stahl, to have constant recourse in their explanations, to the soul, they tried to find a philosophic proof of the existence of material forces, to show that matter, as mere matter, is endowed with particular forces, with which they might satisfactorily explain a great many of its phenomena. No one had hitherto sought for a similar proof; for Aristotle had contented himself with an axiom, that all natural things contain in themselves the sufficient cause of their movement and rest. Glisson and Leibnitz set themselves in search of this proof; but it was reserved for the immortal Kant to find it in the nature of matter itself.
"Francis Glisson may with propriety be considered as the precursor of Leibnitz. What he tried to demonstrate by scholastic subtlety, and by thousands of syllogisms, was developed by Leibnitz with a clearness and ability, which secured the suffrages, even of the unenlightened. Both of them went too far, in attributing life and sensation to matter, instead of claiming for it the two simple and primordial forces of attraction and repulsion.
"Glisson sets out with the idea of substance, but he does not explain it with sufficient precision. Every substance has three substantial rudiments,—fundamental substance, by means of which it exists,—energetic substance, by means of which it acts,—and additional substance, which determines its accidental qualities. All matter, as substance, must have an energetic substance or nature, which is the internal principle of movement. Therefore whatever moves spontaneously, and in virtue of an internal force, must feel this motion, and desire it. All matter feels that it is, and that it exists by itself. It has therefore, consciousness of its own nature. Life consists in the activity of the internal substantial energetic nature. Death is the dissolution of the triple alliance of the internal energetic substantial nature, with the vegetative and animal natures, which two last belong to the additional substance."[28]
In applying his theory to physiology, Glisson's idea is, that the fibres of the human body are endowed with a force, which he divides into three kinds; to wit, natural or inherent force, (robur insitum)—vital force, (robur vitale)—and animal force, (robur animale.)
Natural or inherent force, is a part of the constitution of the fibre, and is as much a property of its organization as are its tenacity, tensibility, &c. The sum of this force varies, in proportion as the constitution of the fibre is more or less perfect. It is strongest in athletic men and strong animals, and weaker in relaxed and debilitated persons. It may be compared with the contractilité de tissu of Bichat.
The second, or vital force, is something superadded to the inherent sort. It is an influxus, derived to any fibre or set of fibres, from that greater sum of force, which arises out of a more elaborate, complex, and exalted organization. It varies in proportion as the vital spirits flow with more or less freedom; and in proportion as their quality is more or less perfect.
The third kind, or robur animale, may be supposed to depend on the organic constitution of the brain and nerves, and varies according to the state of that organization. We cannot help adverting to the resemblance between these two latter kinds, and the contractilité organique, and contractilité animale, of Bichat; and this robur comprises, as we shall show hereafter, both the contractilité and sensibilité of the French physiologist.
Glisson, in his chapter de Irritabilitate fibrarum, commences by remarking that a motive faculty existing in any fibre, unless it were of an irritable nature, would leave such fibre in one of the two following states: 1. It would either never cease from action, or 2ndly, being once at rest, its motion could never be reproduced; but the varieties and differences which we see in the actions of fibres, clearly demonstrate them to be possessed of irritability: i.e. if a fibre may be by turns in a state of action and repose, it is evidently possessed of a quality, whereby it can be induced to move if in a state of rest; this quality he terms irritable, or irritability. The next inference from this power of alternate activity and repose is, that the fibre is possessed of a faculty, whereby it can perceive an irritation offered to it; but this perception of irritation further implies an appetence for a change of its actual state, before the motion can really take place. Perception, appetence, and motion, make a triunit. "In the mean time, says he, as sensitive appetence, and sensibility, are frequently confounded with natural perception, in this irritation of the fibres," he divides it into three kinds, viz. Natural Perception, Sensitive Perception, and Perception regulated by animal appetency.
Natural Perception is that principle whereby a fibre perceiving any alteration offered to it, whether pleasing or displeasing, is excited either to accept that change, or to avoid it, and moves accordingly.
Sensitive Perception, is that kind, in which a fibre, perceiving a change effected in some other organ, is impelled ad aliquid appetendum, and to move conformably.
The third sort, or Perception regulated by animal appetency, is that in which the brain directs from within, such movements of the muscular fibres, as are requisite for the execution of any purpose.
"Some persons," says Glisson, "may doubt whether there really exists a natural perception of irritation in the fibres; but we have elsewhere asserted in general the reality of natural perception, to wit, in my work, de Vita Naturæ; and whoever has known it, will readily admit this quality in fibres imbued with inherent, influent, and vital spirits. We do not expect, in this place, to establish it as a general principle; but if any proof, derived from a knowledge of the structure, uses, and actions of the fibres, can be adduced, it may be here attempted."
"It is indubitable that the fibres are alternately at rest and in motion; for, during sleep, they are all relaxed, with the exception of such as subserve the functions of respiration and circulation, and even these are by turns quiet and active. During waking again, they are all in a state of moderate tonic motion; and moreover, during all movements of the limbs, the antagonist muscles yield spontaneously, the abductors being active, while the adductors are relaxed, and vice versa. Hence it is manifest, that the fibres are alternately quiescent and active: but, since they are not principal or sui arbitrii agents, it is necessary, in order to the new movement, that they should be irritated from some source: for, it is impossible that a fibre in repose, can be set in action without an irritating cause; nor can we conceive of a part being irritated without perceiving the irritation. It is like speaking to a deaf man, or trying to awaken a dead one."
"If you say, fibres are possessed of sensibility, and can be excited by virtue thereof, I confess that they are sensible parts, and may thereby perceive some, not all irritating causes; but whether sensation excites them immediately, or rather, is transmitted to the brain, and irritates the animal appetency; and further, whether the animal appetence, effects a movement in them directly, and to what sort of perception this irritation may be properly and immediately ascribed, is detailed in order below, when we come to explain sensitive perception, and perception à phantasia imperata."
"Let us now go on to point out those cases, in which no suspicion of sensation can be entertained. The pulsation of the heart is neither effected nor affected by sensation; its fibres, in virtue of the irritation occasioned by the blood in its ventricles, are excited to contract, and thus occasion the pulsation, but when the irritation is remitted they relax, and recover the natural state. Now it cannot be denied that this is an evident case of irritation of the fibres, for according as is the irritation, so is the rythm of the pulsation, which varies at times, as in febrile and other affections: nor is it right to pretend that there is any sensation in this case; because this perception of irritation per vices, is exercised as well during sleep, when the senses are all locked up, as in the waking condition. The fibres do not, therefore, perceive in these actions by a sensitive, but by a natural perception, the irritation of the vital blood, which animates them to alternate contraction and relaxation. This is corroborated by those tumultuous irregular motions which continue in animals after decapitation; so also the intestines when still warm in a recently opened animal, move and twist about; the muscles in dead animals also, excited by the perception of cold, contract with a strong tonic movement, and render the body rigid. The hearts of some animals too, when torn out of the body, and even when dissected, continue their endeavours to pulsate. Is there any further evidence wanting? We may hence infer with sufficient confidence that the fibres (without the aid of the senses) may perceive irritation, and move themselves conformably."
In the next place he examines the nature of sensitive perception of fibres, and goes on to show how an impression made on an external part, or a natural perception, becomes converted into sensation, and thus made known to the sensorium. But his disquisition is not only very long but very dark, and we shall therefore pass it by with the exception of the following.
"Natural perception includes within itself a rationem positivam, and a negationem formalem.
"The ratio positiva is the perception of the idea, or image of the object moving or changing the fibre.
"The negatio formalis is a denial or refusal to communicate this image to the sensorium. In the process of transformation into sensation, the positive ratio is not changed, but remains the same, and is the first part, or basis, both of internal and external sensation.
"The negatio formalis is destroyed or abolished in any case of impression communicated to the sensorium. Natural perception, in its ratio positiva, is not abolished or degraded by being converted into sensation, but is rather exalted, or gifted with a more dignified nature. By as much as public or general knowledge is preferable to private, or public advantage to that of an individual, by so much is sensation preferable to natural perception. Hence nature formed so many organs of sense, that the phantasy might have notice of what ought to be done, desired, or avoided."
He does not doubt that external sensibility is inherent in the nervous parts of the external organ, whence he infers that it may readily incite the fibres of such organ ad appetendum et movendum; for, as external sensation is communicated to the brain by means of the nerves, it must of necessity be true, that these nerves and nervous parts (such as the fibres,) are the subjects of it. Since then sensibility causes its subject to feel, it consequently enables it to desire and move comformably. For perception in any subject is vain, unless it can desire, and appetence is useless, unless it can move. External sensibility, therefore, may be said to render the fibres actu irritabiles, for example, as often as the irritating cause is perceived; but as the irritation is perceived, not by a sensibility, but by a mere natural perception, this it is which constitutes their irritability.
Thus we may perceive that the triunit consisting of perception, appetence, and motion, constitutes the celebrated irritability of our author. But he has been too latitudinarian in his application of the theory; for he did not limit it, as Haller has subsequently done, to one sort of fibres, or indeed to fibres alone, for he says in cap. IX., "It is to be remarked that natural perception belongs to other parts of the body besides fibres; to wit, to the parenchymata, bones, marrow, fat, blood, recrementitious juices, humours of the eye, and such like, all which are irritable, and increase the irritable constitution of the parts, but these parts hardly admit of the existence of animal perception." Haller blames Glisson for having gone so far in his application of the theory, and it is well known that he himself restrained it to the single tissue of muscular fibres, and denominated it vis insitum, or inherent force; whereby he distinguished it from his vis mortua or elastic contraction, on the one hand, and the vis nervosum or voluntary power, on the other; the former being something less, and the latter something more than irritability. Glisson's theory, when fully explained, which we cannot for want of space do here, will be found to bear a very strong resemblance, in many points, to that of Bichat, who has invested the matters of the body with vital powers, far beyond those attributed by Haller; and as we are not furnished in the present article with sufficient space, we hope in some subsequent number, to place this matter in a plainer light before our readers. In the mean time we may remark, that Glisson seems to be the first of those who have placed the subject fairly before the medical public; for although faint traces of a similar theory may be perceived before him, especially by translating terms into their equivalents, yet he has the merit of using a term which, in spite of all subsequent modifications, is in daily use.
Glisson's latitudinarianism may be contrasted with Haller's rigid application: for the latter says, "I call that an irritable part of the human body, which on being touched by a foreign body, renders itself shorter;" thus while Glisson attributes his triunit of perception, appetence, and motion to all the tissues and fluids, Haller confines it to muscular fibre alone. No one can doubt that the membranes of the body are endowed with vital properties, but yet they do not shorten themselves on being touched by a foreign body. Bichat has distinguished their vitality as organic vitality, and the contractile qualities displayed are divided into insensible organic contractility, and into contractility of tissue: but these sorts of contractility mount up by insensible gradations. He says, that "entre la contractilité obscure mais réelle, necessaire a la nutrition des ongles, des poils, &c. et celle que nous presentent les mouvements des intestins, de l'estomac, &c. il est des nuances infinies, qui servent de transition: tels sont les mouvements du dartos, des arteres, de certaines parties de l'organ cutané," &c. We will close with a comparison between Glisson's irritability, and Bichat's contractility. At page 70 of the Treatise sur la Vie & la Mort, Bichat supposes that a "muscle enters into action, 1st. by the influence of the nerves which it receives from the brain, and this is a case of contractile animale," (which differs in no respect from perception regulated by animal appetency of Glisson). 2ndly. According to Bichat, the muscle enters into action "by the excitation of a chemical or physical stimulant applied to it, and which artificially determines a movement of the whole muscle, analogous to what is natural to the heart, and other involuntary muscles. This is sensible organic contractility or irritability," and corresponds to the sensitive perception of the old English physiologist. In the 3d place it enters into action by the stimulus of the fluids which circulate in it, and this is insensible organic contractility or tonicity of Bichat, and is nothing different from Glisson's natural perception. Bichat makes a fourth case; as for example, when a muscle is divided across, it contracts by a contractilité de tissue, or par defaut d'extension. We do not perceive how Glisson's natural perception can be applied to this case, but he treats of it in his fifth chapter under the head of Cessatio: it is that state to which a fibre is reduced when left to itself, and freed from all stimulus.
Bichat has attributed to some fibres the power of active elongation. On this subject Glisson says, "Impossible enim est, ut simplex fibra, sua sola actione, se secundum longitudinem distendat, nec modus quo hæc fiat concipi nedum effari queat non negavero quin in distensione hac, aliqualis fibræ actio includatur, sed ea tota contractiva est, & distensioni ab extranea causa factæ reluctatur." A doctrine as sound as that of the 47th proposition; a doctrine too, without admitting which, we think no man can understand the theory either of simple inflammation, or of the febrile affections. We hope to resume this subject at an early period.