Epileptic and other convulsive affections of the nervous system

Front matter

'v

22102106154

AND OTIIEK

Chapter II. On convulsive affections which are characterised by tremor . 183

The general history of these affections . . . 433

Ordinary trembling ..... 183

Paralysis agitans . pgg

Delirium tremens . 4g4

The rigors and subsultus of fever . . . 455

The tremblings of slow mercurial poisoning . . 185

The pathology ..... Igg

Thi! treatment . . . . jgq

Chafteu III.

On convulsive affections which are characterised by simple convulsion 191 The general history of these affections . . . 191

Hysteric convulsion ..... 191

The paroxysm ...... 196

Hysteric convulsion . . . ' . . 196

Certain varieties of chorea .... 201

The dance of St. John ..... 202

The dance of St. Vitus ..... 203

Tarantism ...... 204

The Tigretier ..... 205

Cases in some degree analogous .... 206

The pathology ...... 210

The treatment ...... 228

Chapter IV

On convulsive affections which are characterised by epileptiform convulsion ...... 235

The history of epileptiform convulsion . . . 235

In chronic softening of the brain . . . 235

In chronic meningitis ..... 235

In tumour of the brain .... 239

In induration of the brain .... 244

In atrophy of the brain .... 244

In congestion of the brain .... 245

In apoplexy ..... 246

In inflammation of the brain .... 251

In urinacmia, &e. . . . . • 256

In difficult dentition, worms, &c. . . . 259

In the moribund state .... 261

The pathology of epileptiform convulsion . . . 262

The treatment of epileptiform convulsion . . . 275

Chapter V. On convulsive affections which are characterised by spasm . 290

The history of these affections .... 290

In catalepsy . 290

In tetanus ...••• 290

In cholera ...••• 294 In hydrophobia . 294

In ergotism ...••• 296 In cerebral paralysis . 297

In certain diseases of the spinal cord ... • 298

In certain cases of minor moment . • • 201

The pntliology of these affections . 203

The treatment ...••• 210

ON

EPILEPTIC AND OTHEK

OF THE

NERVOUS SYSTEM.

Introduction

In opposition to the theory which supposes that muscle is endowed with a vital property of contractility, and that contraction is brought about when this property is roused or excited or stimulated into action, it may be held that there is a state of polarity in living muscle during relaxation which produces relaxation, and that contraction is nothing more than the necessary result of the muscle being liberated from this state and left to the operation of the attractive force which is inherent in the physical constitution of the muscular molecules. It may be held, indeed, that a change is necessary which shakes to its very centre the pathology of all convulsive affections of the nervous system, for it is evident that the physiology of muscular motion must be the corner stone upon which the pathology of convulsion is built up.

Ten years have now elapsed* since I first endeavoured

* ‘ Philosophy of Vital Motion,’ 8vo, Churchill, 1851.

.1

INTRODUCTION.

to show (vely lamely, I confess) that the latter theory of muscular motion is the correct one. Before this time others had written with a similar object in view, but I was not then aware of this fact, nor did I become aware of it for several years subsequently.

The name which must he mentioned first in order is that of Dr. West, of Alford, in Lincolnshire. As early as 1832,* in some remarks upon the influence of the nerves upon muscular contractility, this writer maintains, “ that the nervous influence which is present in relaxed muscular fibre is the only influence which the nerves of volition possess over that tissue ; that its office there is to restrain or control the tendency to contract which is inherent in the muscle ; and that contraction can only take place when by an act of the will this influence is suspended, the muscle being then left to act according to its own innate properties . . and again, “ that nervous influence is imparted to muscular fibre for the purpose of restraining its contraction, and that the action of the will, and of all other disposers to contraction, is simply to withdraw for awhile this influence, so as to allow this peculiar property of muscular fibre to show itself.” The coexistence of spasmodic action with nervous debility, the efficacy of stimulants as antispasmodics, and the postponement of rigor mortis until all traces of nervous action have disappeared, are the principal facts which are adduced in support of the probability of this theory.

Very shortly after the publication of these remarks/ a similar idea appears to have been hinted at by Sir Charles Bell in a lecture at the Royal College of Surgeons in London, for, after premising that the question could never he settled, the lecturer said, “ that relaxation might he the act, and not contraction, and that physiologists, in studying the subject, had too much neglected the consideration of

* “On the Influence of the Nerves over Muscular Contractility,’’ ‘ London Medical and Surgical Journal,’ edited by Michael Ryan, M.D., vol. i, 1832.

INTRODUCTION.

the mode by which relaxation is effected.” This remark is preserved by Dr. West in the essay to which reference has just been made.

Six years later, in a chapter of his classical work on comparative anatomy,* Professor Duges, of Montpellier, argues with much clearness that all organic tissues are the seat of two opposite movements — expansion and contraction, and that contraction, which is in no sense peculiar to muscle, is nothing more than the cessation of expansion — “ la contraction musculaire lie consiste que dans P annihilation de ^expansion.” The muscle is supposed to contract in virtue of its elasticity, just as a piece of caoutchouc might contract when set free from a previous state of extension ; and an analogy is hinted at between the expanded state of the muscle and the fluid state of the fibrine of the blood, and between rigor mortis and the coagulated state of this fibrine. Analogous in its effects to electricity, the vital agent is supposed to accumulate in the muscles, and to produce expansion by causing the muscular molecules to repel each other; and contraction is supposed to be brought about either by the sudden discharge (as in ordinary contraction) or by the gradual dying out (as in rigor mortis) of the vital agent. And, further, it is supposed that the rhythmical movements of muscle are caused by successive discharges of the vital agent, which discharges are brought about whenever this agent acquires a certain degree of tension; and that the cramps of cholera, or the spasms of tetanus or hysteria, are consequent upon the development of the vital agent being for the time suspended.

More recently still, namely in 1847, Professor Matteucci communicated a paper to the Parisian Academy of Sciences! upon the influence of the nervous fluid, in mus-

* ‘Traite dc Physiologie compare de l’Homme et des Animuux,’ 8vo, Montpellier and Paris, 1838.

t ‘ Comptes Rendus,’ March 17th, 1847.

4‘ INTRODUCTION.

cular action, in which he writes : — “ Ce fluide developpe principalement dans les muscles, s’y repand, et, doue d’une force repulsive entre ses parties, comme le fluide electrique, il tient les elements de la fibre musculaire dans un etat de repulsion analogue il celui presente par les corps electrises. Quand ce fluide nerveux cesse d’etre libre dans le muscle, les elements de la fibre musculaire s’attirent entre eux, comme on le voit arriver dans la roideur cada-

verique Suivant la quantite de ce fluide qui cesse

d’etre libre dans la muscle, la contraction est plus ou moins forte.” Professor Matteucci appears to have framed this hypothesis, partly, in consequence of certain considerations which seemed to show that the phenomenon of “ induced contraction” was owing to the discharge of electricity in the muscle in which the “inducing contraction” was manifested— an idea originating with M.Becquerel — and, partly, in consequence of the analogy w'hich he himself had found to exist between the law of contraction in muscle and the law of the discharge in electrical fishes ; but he does not appear to have attached much importance to the hypothesis. Indeed, his own comment at the time is — “j’ai presque honte d’avoir eu la hardiesse de communiquer it l’Academie des idees si vagues, et apparemment si peu fondees, et contre lesquelles on pourrait faire bien des objections, mais je pense que, parmi les theories physiques les inieux fondees aujourd’hui, il on existe qui ont debute de cette maniere, et il est certain que des hypotheses, aussi peu fondees que celles-ci, ont quelquefois peu produire ensuite des decouvertes rcmarquables.”

Next in order, and almost contemporaneous. y with the date of my own first publication on the subject, Professor Engel, of Vienna, wrote:* — “So hat der Nerve die Aufgabc, nicht die Zusammenzichungen des Muskcls zu veranlassen,

INTRODUCTION.

sondern den Zusammenzieliungen bis auf einen geringen Grad entgegenzuwirken. Ira lebenden Organismus, in welchem Iiuhe etwas Unmogliches ist, ist auch ein rubender Muskel eben so wohl wie ein ruhender Nerv undenkbar, der Muskel in seinem bestandigen Streben, sich zusammenzuziehen, wird vom Nerven daran verhindert, im Nerven macbt sicb das fortwahrende Streben kund, die Zusammenziebung des Muskels auf ein gerechtes Mass zuriickzufuhren ; das Ergebniss dieser zwei einander entgegengesetzen Eigenscbaften der Nervens und des Muskels ist das, was man gemeinbin Zustand der Rube, Zustand des Gleicligewichtes, oder an Muskeln aucb Tonicitat nennt. Das Yerlassen dieses Gleicbgewicbts ist die Bewegung einerseits, die Labmung andererseits. Die Bewegung wird aber erzeugt, indem entweder der Einfluss des Nervens auf den Muskel herabgesetz wird, oder indem die Contractionskraft des Muskels unmirtelbar gesteigert wird. Lahraung des Muskels findet sicb gleichfalls entweder durch unmittelbare Yernicbtung der Contractionskraft des Muskels oder durcb eine iibermassig gesteigerte Einwirkung des motoriscben Nervens auf den Muskel. Sollen daher abwecbselnde Muskelcontractionen zu Stande kommen, so ist die Gegenwart des lcbendigen Nervens im Muskel unerlasslich, und auch bei unmittelbaren Muskelreizen konnen abwechselnde Zusammenziehungen nur erfolgen, so lange nocb die Nerven lebensfahig sind; hort letzeres auf, so zieht sicb der Muskel ohne Hinderniss zusammen. Diesen Zustand nennen wir die Todtenstarre.” The chief grounds for this opinion are, first, certain original experiments, some of them very remarkable, which afford additional proof that the muscles of frogs are more prone to contract when they are cut off from the influence of the great nervous centres, secondly, the frequent spontaneous occurrence of cramps and other forms o£ excessive spasmodic contraction in

INTRODUCTION.

paralysed parts, and, thirdly, the supervention of the permanent contraction of rigor mortis when all signs of nervous irritability are completely extinguished.

And, last of all, I find Professor Stannius, of Rostock,* arriving at the conclusion — “dass es eine wesentliche Aufgabe der sogenannten motorischen oder Muslcelnerven sei, die natiirliche Elasticitatsgrosse der Muskelfasern herabzusetzen und ihre Elasticitat vollkommener zu machen ; dass anscheinende Rulie des Muskels, zum Beispiele, wahrend des Schlafes, das Stadium solchen regen, den Muskel zu seinen Aufgaben weider befahigenden Nerveneinflusses anzeige ; dass active Muskelzusammenziehung einen geregelten und begrenzten momentanen Nachlass des Nerveneinflusses auf den Muskel bezeichne ; dass endlich die Nachweisung einer Muskelreizbarkeit, in der iiblichen Auffassungsweise, ein durchausvergeblichesBemfihen sei.” M. Stannius was led to this conclusion by certain original experiments, in which he found blood to have the power of relaxing rigor mortis and restoring muscular irritability, and these experiments are advanced in evidence. Reference is also made to arguments, to be brought forward on another occasion, which will prove — “ dass diesse Anschauungsweise, so paradox sie immer auf den ersten Anblick sich anlassen mag, mit unserem thatsachlichen Wissen fiber Nerven- und Muskelthatigkeit keineswegs im Widerspruch steht/’ The essay from which these quotations are taken was published towards the end of 1852 — about two years after the date of my own first publication on the subject.

I do not stand alone, then, in thinking that a great change is necessary in the theory of muscular motion — a change amounting to no less than a complete revolution ;

INTRODUCTION.

ancl I am glad that it is so, for thus supported, I am the more bold to challenge attention to the facts and arguments which will be advanced in the following pages.

Under these circumstances, therefore, it is necessary to aim at acquiring clear views respecting the physiology of muscular motion before entering upon the consideration of the many and difficult questions relating to the pathology of convulsive affections, and thus the primary division of the present inquiry will be into two parts, one physiological, the other pathological —

Part I. — Physiological preliminaries respecting muscular motion.

Part II. — Pathological deductions respecting epileptic and other convulsive affections of the nervous system.

NOTE.

In the following pages I find it expedient, in many places, to avoid the use of the term irritability and its cognates. I do this because these terms are part and parcel of that particular theory of muscular motion from which I am constrained to dissent, and because I cannot use them in a different sense without giving rise to frequent confusion of thought. What I propose to do is to use the ivords incite, incitation, incitable, incitability, in place of irritate, irritation, irritable, irritability. In their derivation the words incite and excite are closely akin, but the former word differs from the latter in not having been assigned by

INTKODUCTION.

common usage to the current theory of muscular motion, and in not conveying in so full a degree the idea of acting by rousing, or animating, or stimulating. In its primary sense, indeed, the meaning of the verb to incite is rather to stir up simply, and other meanings are secondary to this. At any rate there is no good reason why I should not use the word, as I propose to use it, in this restricted sense. In speaking of an incitable muscle, then, all that I shall mean is a muscle which is capable of transitory contraction in the sense in which an irritable muscle is capable of transitory contraction. In speaking of an incitable nerve, all that I shall mean is a nerve which has that capability of producing contraction or sensation which belongs to an irritable nerve. In speaking of muscular incitability , all that I shall mean is that capability for contraction which is implied in the idea of muscular irritability as contradistinguished from the idea of muscular tonicity. In speaking of nervous incitability, all that I shall mean is that capability for producing contraction or sensation which is implied in the idea of nervous irritability .

PART I.

PHYSIOLOGICAL PRELIMINARIES RESPECTING MUSCULAR MOTION.

PHYSIOLOGICAL PRELIMINARIES.

In endeavouring to arrive at a satisfactory theory of muscular motion, the course which seems to he least roundabout is that of which the principal stages are marked out in the five following chapters, and this, therefore, is the course which I propose to pursue : —

Chapter III. — On muscular motion in relation to the action of electricity

Chapter IY. — On muscular motion in certain other relations, and on the theory which seems to apply to simple muscular motion.

Chapter Y. — On the applicability of this theory to rhythmical as well as to simple muscular motion.

PHYSIOLOGICAL PRELIMINARIES.

Chapter I. On Muscular Motion In Relation To The Action Of

THE BLOOD.

The fact, which has not yet lost its novelty, that after the full establishment of rigor mortis the relaxed and incitable condition of the muscle may be restored by the injection of blood into the muscular vessels — a fact which has been abundantly , demonstrated by Dr. Brown-Sequard* and Professor Stanniust — may well serve as a text for introducing what has to be said in the present chapter.

One of Dr. Brown- Sequard’s experiments by which this fact is established was upon the arm of a criminal who had been guillotined at 8 a.m. on the 12th of July, 1851. The experiment, which consisted in injecting and re-injecting a pound of defibrinated dog’s blood into the brachial artery, was commenced at 11 p.m. — fourteen hours after decapitation. At this time the limb upon which the injection was practised was in a perfect state of rigor mortis. As the blood began to penetrate into the vessels, some reddish spots appeared in different parts of the skin of the forearm, of the arm, and, more particularly, of the wrist. Very quickly these spots became larger, and the skin acquired the appearance it has in rubeola. Soon afterwards the whole surface had a reddish-violet hue. A little later, and the skin had acquired its natural living colour, elasticity, and softness, and the veins stood out distinct and full as during life. Then, the muscles relaxed, first in the fingers, lastly in the shoulder, and on examination they

* ‘ Comptcs Ilendus,’ June 9th and 25th, 1851. f Op. cit.

were found to liave recovered their lost incitability. At 11-45 p.m. the muscular incitability was more decided than it was at 5 p.m., at which time the corpse was first examined ; and from 11-45 p.m. until 4 a.m., when fatigue compelled the experimenter to abandon his labours, there was no alteration in this respect. When the experiment was commenced the temperature of the blood was 75° Fahr., and that of the room 66° Fahr.

The subject of another experiment was a full-grown rabbit, which had been killed by haemorrhage. Dr. Brown- Sequard waited until rigor mortis had fully set in, and then injected the defibrinated blood of the same animal into the principal vessel of one of the hind limbs, which limb had been previously removed from the body. Fifteen minutes after the commencement of the injection the muscles had lost their stiffness, and responded readily to mechanical and galvanic incitation. From this time, throughout the night, until 3 p.m. on the day following, the blood was injected at intervals of' from twenty to thirty minutes, and during the whole of this time the muscles remained perfectly soft and incitable. All this while, also, the muscles of the companion hind limb and of the rest of the body were in a perfect state of rigor mortis. Between 3 p.m. and 4-50 p.m. the injections were discontinued, and, in this interval of aii hpur and a half, the limb (with the exception of a few bundles of fibres here and there) had time to return to the former state of rigidity. U rider the second injections the muscles once more and speedily became soft and incitable, and in this -state they continued until, from the lateness of the hour, the experiment was again abandoned. On the morning following, the parts of the body which had been left to themselves were beginning to pass out of the state of cadaveric rigidity, but the limb upon which the injections had been practised was perfectly stiff. On the third morning rigor mortis was still undiminished in this

PHYSIOLOGICAL PRELIMINARIES.

latter limb, and, in marked contrast to this state, the muscles of the rest of the animal were soft and in an advanced stage of putrefaction.

About the time that Dr. Brown- Sequard was engaged in these and other experiments of the kind, Professor Stannius, without any knowledge of what was being done in Paris, was carrying out an analogous series of inquiries at Rostock.

On the 21st of July, 1851, for example, at 7-30 a.m.. Professor Stannius put a ligature around the abdominal aorta and crural arteries of a puppy. A few minutes after 10 a.m. the muscles had begun to stiffen in the parts from which the blood was excluded. At 1045 a.m. both hinder limbs were stretched out, and perfectly stiff and cool. At 11 -40 a.m. the ligatures were loosened, and the blood was seen and felt to penetrate into the empty vessels. At 1 1’45 a.m. the natural warmth had returned in some degree, and the right hinder limb was a little more flexible than the left. At noon both these limbs had recovered their flexibility, and it appeared once as if the left had moved spontaneously, but no sign of pain was caused by pinching the toes. At 12'30 p.m. the muscles of the paralysed limbs contracted everywhere upon the application of the galvanic poles ; and at one time the galvanism seemed to cause pain, for the animal, which was before quiet, gave a sudden plunge forwards when touched by the poles. Death happened unexpectedly at 12'45 p.m.

Early upon the morning of the day following, a similar experiment was performed upon another puppy. At noon, in this case, there was no evidence of stiffness in either of the hind limbs, but the muscles below the knees had ceased to respond to the touch of the electrodes. At 215 p.m. both these limbs were stretched out and rigid, and all evidence of incitability was at an end. At 2'35 p.m. the ligatures were untied. At 3 35 p.m. the application of the electrodes caused strong contraction in the muscles of both thighs, and weaker contractions -in the muscles of the left leg below the knee, and there were hut few traces of rigidity anywhere. At 5'35 p.m. the muscles, now perfectly soft and pliable, responded readily to the prick of a knife as well as to the touch of the electrodes. On the following morning the animal was found dead.

In another experiment, in which the abdominal aorta and the crural arteries of a,fine puppy were tied and left tied to the end, Professor Stannius shows very clearly that the rigidity of which mention is here made is perfectly identical with rigor mortis. In this case, four hours after the operation, the muscles below the ligatures were perfectly rigid and devoid of incitahility. In the evening of the day following there was no alteration in this state. Twelve hours later the animal was found dead, with the parts above the ligatures in a state of rigor mortis, and with the parts below the ligatures, which had been rigid before death, flaccid, moist, and partially putrescent. In other words, the parts below the ligature were in the state which comes on after rigor mortis, and hence it follows that the stiffness which had existed in these parts before the death of the anterior half of the animal must have been identical with rigor mortis.

Here, then, are certain experiments which would seem to show that the influence of the blood, be this what it may, is exercised in counteracting rigor mortis. And this inference, which I had drawn from the experiments of Dr. Brown-Sequard before my attention was directed to those of Professor Stannius, is the same as that which the last-named physiologist has drawn from his own experiments.

There are, however, certain facts* which seem to show that muscle is affected differently by arterial and by venous blood, and these facts have led Dr. Brown-Sequard to think * ‘ Comptes Rendus,’ No. 1 G, 1857.

PHYSIOLOGICAL PRELIMINARIES.

that the office of arterial hlood is to minister to the nutrition of muscle and other tissues, and to the storing up of contractile and other forms of power, and that the office of the venous blood is to supply a stimulus by which the power derived from the red blood is called into action — a view according to which the function of the black blood is no less important to the interests of the economy than that of the red hlood. *

The chief argument in favour of the idea that venous hlood is endowed with these stimulating properties is based upon the well-known fact that the muscles contract violently when the whole mass of hlood becomes venous, as in asphyxia. Another argument, also found among the phenomena of asphyxia, is derived from the fact that the pulse is fuller and stronger, and that the mercury rises to a higher point in the hsemadynamometer, when black hlood is being pumped into the arterial system. Other arguments are found in some original experiments in which Dr. Brown-Sequard finds that certain involuntary muscles may he thrown into or out of a state of contraction by injecting alternately black and red blood into the vessels. In one of these experiments, for example, the uterus of a pregnant rabbit was separated from its connexions with the cerebro-spinal centres and blood injected into the aorta. On injecting black blood the uterus contracted, and two or three foetuses were expelled; on injecting red hlood these contractions immediately passed off.

But, it may be asked, is it not possible that these contractions may he due to the want of arterial blood rather than to the presence of venous blood ? And is not such an explanation the less difficult of the tivo ?

It is certainly true that an animal is as violently convulsed when it is bled to death as when it dies by strangling. In other words, it is certainly true, that the convulsion Avhich depends upon the vessels of an animal being suddenly

V

emptied of blood is every whit as violent as tbe convulsion which is brought about by causing the vessels to become suddenly filled with black blood. And thus, on taking the two cases together, the convulsions would seem to be related to the absence of arterial rather than to the presence of venous blood, for absence of arterial blood is a cause which must operate, not in one case only, but in both. At any rate, with this fact of convulsion from haemorrhage to account for, it is evident that venous blood cannot be regarded as an essential element in the process of convulsion.

Nor is the fuller and stronger pulse of the first moments of suffocation a certain sign that the left ventricle is then being stimulated to more vigorous contraction by the black blood. On the contrary, this phenomenon may be little more than the necessary consequence of the difficulty which the black blood experiences in getting out of the arteries. That this difficulty is a reality was well shown years ago by the late Professor John Reid.* If, for example, the carotid and jugular of a rabbit be exposed, and a ligature placed around the windpipe, the blood in the artery is seen to become rapidly darker and darker, until it is not to be distinguished from the blood in the neighbouring jugular. From two minutes to two minutes and a half are occupied in this transformation of scarlet into black blood. It is found, also, that the arteries are more distended, and that the blood will escape with greater force and in fuller stream when the process of suffocation is at its height — phenomena which are readily explained, as Dr. Reid explained them, by supposing that black blood moves through the systemic capillaries with far greater difficulty than red blood. Recently, moreover, some new facts have been elicited by Professor Draperf (the younger), of New York,

t “ Lectures on the Physiology of the Circulation,” ‘ American Medical Monthly,’ April, I860.

18 PHYSIOLOGICAL PRELIMINAIUJ^.

which are calculated to shed not a little light upon the question under consideration. After the stoppage of the respiration, as Professor Draper shows, the left ventricle and auricle, as well as the right ventricle and auricle, become enlarged from the accumulation of blood within them. At first, the cavities on both sides of the heart are gorged to an equal degree, or thereabouts ; a little later, on comparing the two sides, the left is even more distended than the right. It is evident, also, that the distension of the left side of the heart is preceded by an unmistakeable engorgement of the aorta and arterial system generally, and that the great veins in the neighbourhood of the heart do not participate in the engorgement of the arterial system and of the cavities of the heart. At the time, indeed, wdien the arteries are most distended, the venie cavae, both superior and inferior, would seem to contain less than their usual amount of blood. And, further, it is found that this is the state of things until the elastic resiliency of the coats of the arteries has an opportunity to come into play and empty these vessels — an opportunity which happens when the pumpings of the heart come to an end. Ip a word, the facts are in direct opposition to the commonly received idea that the veins are gorged with blood and the arteries comparatively empty in the earlier moments of asphyxia ; and being what they are, they afford a ready means of explaining why, in these earlier moments, the arterial pulse may be fuller and stronger, without supposing that the left ventricle is then stimulated to more vigorous contraction by the stronger stimulus of venous blood. What is the complete explanation of the fuller and stronger pulse at this time is another matter. It is certain, however, that the ordinary contraction of the ventricle under these circumstances will, in some measure, explain the phenomenon, for the force which ought to be expended in propelling the blood through the capillaries must, just in proportion as it fails to do this, be expended in dilating the coats of the intermediate arteries. At the same time, it is possible that the ventricle may at this time contract with unusual force, for it is not unlikely that this muscle may participate in the violent contractions which are then convulsing the entire muscular system.

It is also possible, without assuming the existence of any hyper -stimulating properties in the venous blood, to explain the contraction of the uterus which is brought about by injecting black blood into the aorta of a pregnant rabbit; for is it not a well-known fact that the uterus has often contracted and expelled its contents when pregnant animals have been bleeding to death in the service of science ? There are, moreover, certain experiments by Dr. O. Spiegelberg,* of Gottingen, which afford special grounds for supposing that the contraction which happens in a case like the one just mentioned is due to the want of arterial rather than to the presence of venous blood. These experiments, which were often repeated upon rabbits, cats, and guineapigs, exhibit the uterus as remaining at rest so long as the circulation is not interfered with, as contracting when the flow of blood along the descending aorta is interrupted by pressure, and as relaxing as soon as the pressure is removed. They exhibit the uterus and intestines as contracting with especial vigour in animals which had been bled to death ; and, in one or two instances, they show in addition a cornu uteri which had been separated from its vascular connexions as contracting more decidedly than the fellow cornu which had not been so separated. They exhibit, also — and this is the fact which is of special interest in the present inquiry — the uterus and intestines as contracting in a much more marked manner after the tying of the abdominal aorta than after the tying of the vena cava or vena porta — as contracting in a much more marked manner, that is to say, * Henle and Pfeuffer’s ‘ Zcitschr.,’ 3 Rcihc, ii, 1857.