the cranium, which was dense and unusually thin. There was a large quantity of serum contained in the cavity of the arachnoid. The substance of the brain was slightly congested. It was in other respects perfectly healthy. The medulla oblongata was small in size and extremely firm in consistence. The foramen magnum was altered in shape. The antero-posterior diameter much diminished. The superior part of the odontoid process of the axis appeared to have been pushed back, and somewhat raised above its usual situation. The antero-posterior diameter was so much narrowed that it would not admit of the little finger. The dura mater and ligament covering the posterior part of the body of the axis, were very much thickened. The atlas was in its usual situation, but the articular cavities were firmly ossified to the condyles of the occipital bone, and permitted no motion whatever between the atlas and skull. There was a slight unnatural projection on the lamina on the right side, between the spinous process and articular process of the axis.

Mr. Holberton, in some observations, gives the following rationale of the case. The injury to the occiput and to the first and second vertebræ at the time af the fall, must have been very great, though insufficient then to cause any visible effect on the functions of the spinal chord.

Inflammation, however, followed, and a consequent thickening of the ligaments, which narrowed the foramen magnum and upper part of the spinal canal, and thus affected the medulla oblongata and upper part of the spinal chord, diminishing the size and increasing the density of these parts.

VIII. MEMOIRS ON SOME PRINCIPLES OF PATHOLOGY IN THE NERVOUS SYSTEM. By Marshall Hall, M.D.

This is the fourth Memoir contributed by Dr. Hall to the Medico-Chirurgical Transactions. It is,

ON THE PLAN OF OBSERVATION OF DISEASES OF THE NERVOUS SYSTEM.

Dr. Hall remarks that sufficient has now been done to show that we, in all investigations of the nervous system, view it as subdivided, not into the cerebro-spinal, and the ganglionic; but into the cerebral, the true-spinal, and the ganglionic; and that, in considering each disease of the nervous system, we must trace its influence distinctly in these three sub-divisions of that system; or, to state this view more emphatically, we must inquire,— 1. What are the distinct diseases of the cerebral, of the true-spinal, and of the ganglionic sub-divisions of the nervous system?

2. What is the influence of disease of one of these systems on the other two respectively?

3. In what order is that influence manifested?

Besides these important questions, there are several others not less momentous. They are these,

1. What are the effects of irritation, and of counter-irritation, of pressure and of counter-pressure, in diseases within the cranium or the spinal canal

2. What is the special anatomy of the base of the encephalon, and its relation to cerebral diseases?

3. Why, with similar symptoms, have we dissimilar morbid appearances within the cranium; and vice versâ ?

4- What are the diseases of the nervous system in which we find, generally speaking, no morbid appearances on a post-mortem examination?

Dr. Hall proceeds to treat briefly these questions and subjects in suc

cession.

1. What are the distinct Diseases of the Cerebral, the True-spinal, and the Ganglionic Systems; their mutual influence, and the order in which they are manifested?

Dr. Hall remarks,-If disease be limited to the cerebrum, its influence is limited to the cerebral functions. If from the cerebrum it extends its influence to the true spinal marrow, the functions of this latter are involved, and spinal symptons are added to the cerebral; or with the cerebral the spinal functions are impaired. This latter condition may frequently be detected by using the reflex function as a test; and in this manner the views of this function, which have recently been laid before the profession and before this Society, come to have their practical application. They afford, indeed, a new source of diagnosis of the nature, seat, and extent of diseases of the nervous system, and consequently of their prognosis.

If the disease be limited in its effects to the true spinal marrow, the symptoms are exclusively spinal, sometimes in excess, sometimes in a defective form. If the cerebral system become also involved, cerebral symptoms are superadded to the spinal.

Similar remarks may doubtless be made in regard to the ganglionic system, viewed in its connections and relations with the cerebral and spinal.

He cites hemiplegia as an instance of affection of the cerebral, tetanus as a sample of that of the true-spinal functions.

Hemiplegia. In cases of hemiplegia, observes Dr. Hall, the danger is precisely in proportion as spinal symptons are superadded to those of the cerebral system. If the respiration be stertorous, if the deglutition be difficult, if the functions of the bladder, rectum, and sphincters be impaired, there is great danger; if these events continue for a considerable time, or if they supervene, the event is always fatal.

The spinal symptoms which exist at first, and gradually yield, probably depend on counter-pressure from congestion; this counter-pressure is relieved by blood-letting, &c., and its effects cease. When, on the contrary, the spinal symptons continue, in spite of the remedies, they probably depend on the extent of the effusion; and this cannot be remedied.

Apoplexy."I need scarcely remark, that in congestion of the cerebrum, in apoplexy, as well as in hemiplegia, if the symptoms of affection of the truespinal system continue, the issue is fatal. In such cases the patient dies of asphyxia; and I cannot but think that tracheotomy might sometimes allow time for the operation of remedies or of nature's resources, and prevent a fatal result. It is well known to the members of this society, that this operation, performed

by Mr. Sampson, of Salisbury, saved the life of a poor patient, dying from the apoplexy of deep intoxication.

I may here observe, that if the stupor and sterter continue, the next series of phenomena are those observed to result from defect of the function of the ganglionic system. The bronchi become clogged with mucus, and the intestines distended and tympanitic from flatus. M. Andral observes-Le stertor de la respiration est en géneral un signe d'un très fâcheux augure, et il est rare que les individus qui le présentent d'une manière prononcée échappent à une mort prochaine. Pour l'expliquer, on trouve sur le cadavre un engoument considerable du poumon, et beaucoup de mucosités spumeuses dans les bronches. C'est véritablement par la gêne de la respiration que succombent les sujets frappeés d'hémorrhagie cérébrale, dans le cas où l'attaque est forte, et où ils meurent promptement.' It is obvious that the stertor is not explained in this manner; but that the bronchial and tracheal rattles which occur under these circumstances are so explained. They constitute, in effect, two orders of phenomena. The stertor depends on affection of the medulla oblongata; the crepitus or rattle on that of the ganglionic system. The latter is precisely the effect observed by Sir Benjamin Brodie, Sir Astley Cooper, and other physiologists, in animals in which the pneumogastric nerves had been divided. But the stertor depends upon the affection of the true-spinal system." 92.

Hydrocephaloid Disease.-"I attended the son of Mr. Howlett, in Thayerstreet, in consultation with Mr. Grant. The little patient was four years old, and laboured under symptoms which seemed to denote the existence of hydrocephalus; there was a state of stupor; the eye-lids were only partially closed, and they were immoveable on the approach, and actual contact, of the finger; the respiration was irregular, and the pulse frequent. I observed that the phenomena presented by the eye-lids would afford a criterion, which would suggest both the diagnosis and prognosis. The history, and the cool and pale condition of the cheeks, suggested the hope that the symptoms depended more upon exhaustion than actual disease within the head. I ventured to give sal volatile, brandy, and nourishment. We had, in a short time, the pleasure of observing the eye-lids become impressible to the stimulus of the finger, the respiration to become regular, and the gradual recovery of the little patient was no longer doubtful." 93.

Mania with and without Paralysis.-Dr. Hall alludes to M. Leuret's position, that mania without paralysis is altogether unattended with organic lesion. He believes that there is a lesion of an intra-vascular kind. fancy this opinion is not confined to Dr. Hall.

We

Tetanus. This disease, says our author, is, in every respect, the most unequivocal example of an affection of the true-spinal marrow, through an incident and the motor nerves. All the functions of this sub-division of the nervous system are affected in the most violent form, whilst the cerebral functions are unaffected: the dyspnoea, the dysphagia, the constipation, the trismus, the emprosthotonos, the opisthotonos, the extreme susceptibility to causes of physical impression and agitation, and of mental emotion, all mark an affection of the true-spinal system; whilst the freedom from all affections of the senses and of the intellect, the absence at once of delirium and of coma, denote the normal condition of the cerebral system. Hydrophobia is in the same category.

Epilepsy.-Dr. Hall thinks that in this the very first symptom is gene

rally, if not always, one of the true-spinal kind. This first symptom is constriction about the throat, and closure of the larynx, more or less complete; then follow violent expiratory efforts and convulsive movements of the trunk and limbs. Intermediately, and even without the convulsive movements, the cerebrum is affected with congestion, and a multitude of cerebral symptoms occur: flashes of light, tinnitus aurium, the aura epileptica; a momentary oblivion; a state of terror, of delirium, or of unconsciousness, &c.; as parts of the general convulsion, the tongue is protruded and bitten, the fæces, the urine, or the semen expelled; as consequences of that convulsion, the cerebrum is congested, and there is coma. If this state continues, another order of symptoms takes place; the respiration becomes stertorous, and, at length, affected with mucous rattle, the true-spinal and ganglionic systems becoming fatally involved in the disease.

It is the constriction about the throat which assimilates epilepsy to the state of things which exists in strangulation, and which distinguishes it from hysteria. It is this circumstance which associates epilepsy with the crowing inspiration and the convulsions of children; all are laryngismal. In epilepsy, there is sometimes a crowing inspiration; the crowing inspiration and convulsion of infants are sometimes followed by epilepsy in subsequent years.

Sinking. The gradual sinking from loss of blood, especially, seems, says Dr. Hall, to involve every part of the nervous system. There is mild delirium or stupor from affection of the cerebral system; there is a peculiar catching motion of the larynx and other organs of respiration, from affection of the true-spinal system, instead of the equable rhythmic movements observed in health; there is an extreme frequency of the pulse; and there is a peculiar crepitant rattle, at first in the small, and eventually in the larger bronchi, and an equally peculiar tympanitic distention of the intestines, from affection of the ganglionic system, all of fatal import. The functions of the cerebrum, of the true-spinal system, and of the ganglionic system, seem to fail altogether.

Shock. The effects of shock have their chief seat in the ganglionic system-the circulation, the secretions are greatly affected.

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"In the presence of a young Parisian student, I divided the spinal marrow in a frog. I pinched the toes, but there was no movement, no reflex action. My companion observed, 'Ah, c'est fini;' I replied, Non, ce n'est pas commencé.' In a few minutes, the reflex actions became obvious, and in a few minutes more, most energetic. We had examined the circulation previous to the division of the spinal marrow. It was most active. But immediately after that division, scarcely a movement was to be seen. Like the reflex actions, however, the vig.

our of the circulation was gradually restored.

In one frog, after the return of the circulation, I crushed the leg and thigh with a hammer. There was no sensation of course, the influence of the cerebrum having been removed. The circulation again immediately ceased. It again returned after a time." 99.

2. The Influence of Irritation, of Pressure, of Counter-irritation, and of Counter-pressure, in Disease within the Cranium and Spinal Canal.

After remarking on the important part played by irritation and pressure in diseases of the nervous system, Dr. Hall adds :-" Not less important, and hitherto overlooked or neglected, are counter-irritation and counterpressure, of which I shall therefore proceed to treat more particularly. The former is induced by slighter causes, as slight effusion into the ventricles, the latter, by the same causes carried to a greater degree."

Counter-irritation.-Dr. Hall thus attempts to explain a fact stated by Andral, and familiar to all, that the same cerebral lesion in different cases will produce different symptoms. He says:

"M. Andral speaks of irritation of the cerebrum as the cause of abnormal muscular contractions. Now, in our investigations into the nature of cerebral diseases, we must remember one circumstance; it is impossible to induce muscular action by any irritation of the substance of the cerebrum itself. Whenever, therefore, there are spasmodic affections in diseases of the nervous system, we must conclude that the spinal system is involved, either primarily or secondarily, in the disease. Irritation of the cerebrum may induce delirium and other disorders of the cerebral functions; congestion of the cerebrum may induce coma, paralysis, &c. But if these morbid conditions of the brain be attended by spasmodic or other deranged actions, it is because the true-spinal system is involved in the disease, or affected by it in the way of irritation, counter-irritation, or of pressure, or counter-pressure. Hence we observe the symptoms of spasm in various diseases of the encephalon, the condition being, not the nature of the disease, but that they produce these intermediate effects. Time, as is well known, is a very important element in this problem; and why is it so? The fact is to be explained on the same principles. The very same lesion occurring quickly, will produce effects which will be totally absent if it creep on slowly. In the former case, we have the effects of irritation and pressure, or of counterirritation and counter-pressure; in the latter, the cerebrum has so accommodated itself to the new state of things, probably by the altered condition of its vessels, as to avoid these effects, except towards the close of the disease.

We need not, therefore, now view with surprise the fact that the same lesion, as found post-mortem, had been attended by a totally different series of symptoms during life, any more than the other fact, that, in the different periods of that lesion, the symptoms have been different.

The symptoms frequently subside too and re-appear. If the disease be not regularly progressive, the encephalon accommodates itself, as I have stated, and the symptoms disappear; if now the disease proceeds, the symptoms also return. At least all this may be.

A rapid effusion of serum may resemble hæmorrhage or ramollissement in its effects; or slow effusion may merely obscure the intellectual faculties." 105.

It is not, therefore, says Dr. Hall, the disease, but its effects upon the brain and spinal marrow, which is the source of the symptoms. If ramollissement, effusion, a tumor, &c. produce similar effects on these textures, the same affection of the functions, the same symptoms, will be observed.

However ingenious this explanation, it leaves the practical difficulty where it found it. The difficulty in question is this:-given, any set of symptoms, what is the lesion? Such symptoms are found in conjunc