All these influences may, I conceive, be pretty readily obviated by an application of a modified character-a solid pad, long and narrow, and curved along the upper edge of the patella. A torniquet so formed, capable of well-graduated pressure, and applied somewhat obliquely and firmly, but without any circular or constricting bands, would, I imagine, act more completely, and with the least necessary violence, without congestion, or any needless obstruction to the nutrient and reparative actions.

It is not now needful to inquire what force is requisite to resist the efforts of the extensors to displace the bone. Doubtless it is desirable to employ the least violence that will be efficient and secure; and my conviction is, that very slight force will suffice, provided the muscles are carefully set at rest, by attention to the patient's posture; and kept unexerted, by studious absence from all motion for the patient's exertions in bed, even with the most precise application of straps, &c. (unless they are so tight as to be very distressing) cannot fail to act upon the injured bone."

VIII. ON THE STRUCTURE OF THE BLOOD CORPUSCLE. By G. OWEN REES, M. D. Physician to the Northern Dispensary; and by SAMUEL LANE, Lecturer on Anatomy.

The human corpuscle, say the authors of the Paper, is circular in form, flattened, and presents a double concave surface. When viewed obliquely and nearly in profile, a central depression is distinctly observed. Its diameter mea sures, on the average, of an inch. The edge will be found to vary much in thickness, as will be afterwards explained. It usually measures about onefourth the diameter. A front view also shows a concavity, the centre of which is destitute of colouring matter; but no distinct nucleus can be demonstrated in its unprepared state. We have, however, frequently succeeded in bringing it into view, by decomposing the globule by means of water, or of a very weak solution of sugar and water. A drop of blood and a drop of water may be placed close together on a piece of glass, and allowed to coalesce; when the nuclei will be found to collect principally about the lower edge of the specimen: or the method recommended by Hewson may be adopted, which consists in placing some serum, loaded with blood corpuscles, on a piece of glass. The specimen is to be viewed while forming an inclined plane in the field of the microscope: and a drop of water is to be added, in such a way that it may flow from the upper to the lower edge of the piece of glass. In its descent it will be found to alter the form of the blood corpuscle, which becomes more rounded and transparent. The nucleus may now be observed in many of the corpuscles, as they roll down the glass: but we have never seen them, as Hewson describes them, moving like a pea in a bladder, as the corpuscle turns upon its axis. In order to convince himself of the existence of a nucleus, the observer should treat the blood of a bird and of the human subject in the same manner. In the former, he will have no difficulty in seeing and separating the nucleus, and in the latter, by transferring the information thus gained, he will, after some little trouble, be enabled to recognize similar appearances, to his entire satisfaction. As we before stated, many of our most accurate observers-Magendie, Hodgkin, and Lister-have denied the existence of a nucleus in the corpuscles of mammalia; and, as far as we know, no description has been given of it, which would in any way meet our views of its form, size, and appearance. The nucleus of the human-blood corpuscle is composed of a thin circular layer, of a colourless substance. Its surfaces are granular, and its edge uneven. It is only about one half less in diameter than the blood corpuscle itself; for which, no doubt, it has been frequently mistaken. It measures from to of an inch in diameter. Its thickness cannot be so satisfactorily stated; it does not appear

It may be de

to be more than one-eighth, or one-tenth of its diameter. monstrated in its moist or dried state, either within its envelope, or separate from it.

Several circumstances have combined to render this nucleus difficult of observation, and which may serve to account for its eluding the notice of so many micrographers. Its thin shape, circular form, and large size, have led to its being mistaken for the blood corpuscle, deprived of colouring matter; while the erroneous notion that the nucleus was a small globular body has not only favoured the misconception, but has led those who have looked for a nucleus of this form to deny its existence altogether. The edge, also, of the nucleus projects so far into the colouring canal, that its defined margin cannot be seen, until this has been destroyed by the removal of the envelope. The envelope in the human subject does not differ in any essential particular from that of the frog. It forms a closed flattened vesicle, the interior of which adheres firmly to the central part of both surfaces of the nucleus, but not elsewhere. The envelope, like the nucleus, is circular, and forms a complete annular canal around it, in which the red colouring matter is situated.

IX. A CASE OF INTESTINO-VESICAL FISTULA. By MR. HINGESTON.

The patient was a gentleman, residing in the heart of London, of strumous diathesis, and corpulent make. He had pretty good health till the 5th of May, 1835, when he dislocated his shoulder, which was easily reduced. On the 21st of September of the same year, he was seized with acute pleurisy of the right side, giving rise to strong arterial action, inflammatory fever, hæmoptysis, &c. demanding prompt venesection, salines, mercurials and abstinence, for its reduction. And in the same year, on the 2nd of December, in the middle of the night, profuse hemoptysis occurred; and venesection was again enforced twice in forty-eight hours, with repose in bed, abstinence, salines, and diuretics.

These two attacks, and the loss of blood consequent upon them, sapped his strength, and evidently made him thinner. In the spring of the following year (1836), he complained of debility; and (May 25th) suffered from passive bronchitis and anorexia, requiring carminatives and warm aperients.

Throughout his life he had always been troubled with diarrhea, which seemed beneficial rather than otherwise; besides being afflicted with a mucous cough, or occasionally with sub-acute bronchitis. It was during one of these attacks that, in the act of coughing, he ruptured himself on the right side (September 5, 1836.) To this hernia, which was inguinal, a truss was applied, and it was cured.

In January, 1837, he had the influenza in a low form. In April he first complained of painful micturition, which subsided in May. In 1838, the "strangury" returned, with the odour and presence of fæces in the urine. In the course of February and March, the malady became excessive and exhausting. Fæces, in a soluble state, streamed away from the urethra, intermingled with urine and gusts of wind; the natural office of the rectum was suspended, or performed with irregular and untimely calls; and the heart and nervous systems were disordered. The urine, at this time, was acid and albuminous.

The plan of treatment adopted was that which was, with some modification, continued to the last; viz. opiates, repose, a pultaceous diet, washing out the rectum, and a regulated temperature night and day. By these means the misery was alleviated, and the natural passage of the rectum kept clear and pervious, while the false outlet through the bladder was lessened or diverted.

In June of this year, the first collapse took place; it followed upon a violent and uncontrollable irruption of wind and fæces through the urethra, completely upsetting the residue of the strength, and threatening speedy dissolution. The

vehemence of the paroxysm was assuaged by successive doses of opium carefully repeated and watched, warm fomentations, diluent diet, and the recumbent posture; followed by ammonia, wine in arrow-root, and sustaining food. The habitual dose of opium, night and morning, was from 30 to 40 minims of Batley's sedative solution.

By diligent perseverance in this plan, the disease was reduced to a state of quiescence. The fæces were passed by their natural course, or but rarely found their way through the bladder, discolouring the urine; and the only evidence of the fistulous orifice continuing unclosed, was the occasional and unexpected explosion of gusts of wind from the urethra. Even these at length ceased, and the year 1838 terminated in a suspension of all threatening symptoms. The constitutional powers, however, seemed to decline.

In February, 1840, at a time when the fistulous opening seemed to be closed and the general health to be much improved, hæmoptysis again recurred, and a cavity was discovered in the top of the left lung. Depletion was requisite. His strength was prostrated-the irruption of the fæcess with the urine recurred -tympanitis was added-and acute peritonitis, unhappily demanding a fresh venesection to twelve ounces, and showing buffy blood, almost seemed to imply that a perforation from the intestines into the abdominal cavity might be impending. The balance of the circulation was now never restored; for venous congestion was manifested, both by the darker hue of the countenance, and the blueness of the nails. Tympanites never ceased to be present; and though the fistulous opening into the bladder became finally silent in August, 1840, yet the evidence of stricture at or about the sigmoid flexure of the colon became every day less and less questionable. Ascites succeeded, and on the 13th of April Mr. Key tapped the patient, and drew off about three pints of fluid. A very feeble reaction developed inflammation along the arch of the colon; under which he sank, April 15th, in the 65th year of his age.

During the anasarca and ascites, the urine was neither alkaline nor albuminous.

Dissection. The body was emaciated, the lower extremities oedematous, and the course, as well as the figure of the colon, could be distinctly traced beneath the integuments, across the umbilicus.

The Abdomen.-On dissecting back the integuments, and laying them open, the colon presented the appearance of a large tromboon, amazingly distended, and stretching across the umbilical region, with its sigmoid flexure, equally large, in the left iliac fossa. The space above its line was occupied by an enlarged liver, and that below by the small intestines.

The omentum was shrivelled, and drawn across to the right iliac fossa; where it was adherent to the parietes above the internal abdominal ring (which was not at all dilated on either side, although a hernia was said to have existed formerly.) The peritoneum was universally opaque and injected; especially arouud the point of paracentesis, and also in both iliac fossæ, where the intestines were involved in a mass of adhesions. There was much buttery lymph both in the bason of the pelvis, and smeared over the surface of the intestines and the intestines were of a very lacerable texture, devoid of scybala, containing only some fæculent matter and much flatus.

The sigmoid flexure of the colon, just above the rectum, the ileum, and the cæcum, with its appendix, were each and all adherent, en masse, to the fundus of the bladder, and involved in a general thickening of the surrounding tex

tures.

Thorax. Both the lungs were firmly attached by old adhesions; especially at their apices, which were interspersed with small tubercular excavations about the size of a bean, and lined by (an acquired) mucous membrane. The surrounding perenchyma was crepitating, and but little consolidated. The basis of each lung was crepitant, and healthy.

The bladder, with the adherent intestines, was removed; and a particular dissection made of them, as follows:

The colon, hypertrophied, singularly muscular, and in circumference about the size of a man's arm, was, together with a convolution of the ileum, and the appendix cæci, adherent to the fundus of the bladder. The natural course of its canal was impeded by a contraction or stricture, which commenced inferiorly in the rectum, about the fore-finger's length from the anus (just at the base of the triangle formed by the vesiculæ seminales), and extended upwards for about two inches, barely admitting the entrance of the little finger. A section of the gut in this part resembled scirrhus; and the glands were, with the surrounding tissues, thickened.

Immediately above this stricture, the coats of the bowel were riddled with ulcerations and openings, leading into a channel which separated the bladder from the intestine. This channel was, in fact, a feculent abscess, situated beneath the reflected portion of the peritoneum, between the bladder and bowel. It was degenerate in structure, lined with a dark membrane, and filled with a muco-purulent excretion. It opened, anteriorly, into the fundus of the bladder; above, into the colon; below, into the rectum; and posteriorly, through the colon into the ileum: so that there was a false passage, by which the natural course of the colon was diverted, and forced between the bladder and strictured part of the intestine down into the rectum below, and at the same place, by means of a fistulous opening, into the bladder in front. The orifice of this fistulous opening within the bladder was curtained by a fungous growth or thickening, which overhung it like a valve Thus, exactly at this point of the fæculent abscess, there was this strange deformation;-the colon-the rectum-and the ileum : each, conjointly with the fæcal abscess, possessed one common entrance into the bladder itself.

Within the bladder, the rugæ of its mucous membrane were vascular, and its muscular coat was considerably hypertrophied.

X. ON CHOREA. By B. G. BABINGTON, M.D. F.R.S.

Dr. Babington remarks that, previous to Dr. Hall's researches, the proximate cause of chorea was supposed to consist in debility, and some degree of irritation of the organic class of nerves: extending more or less to those of volition; and occasioning morbid susceptibility of the nervous system generally, with diminution of power, increased mobility, and irregular actions of the muscular system, particularly of those muscles supplied with the nerves principally affected.

Let us contrast this loose and general account of the pathology of chorea with that offered by Dr. Marshall Hall. He first maintains, as principles of physiology, that, besides the contractile power in muscular fibre itself, there are three causes of muscular motion:-1st, Volition; the seat of which is the cerebrum, and the action of which is conveyed along the fibres which decussate in the medulla oblongata. 2ndly, The direct and reflex action of the excito-motory system. And 3dly, Emotion.—He affirms, that the seat of emotion is below that of volition; is in the medulla oblongata; and acts along fibres which probably do not decussate; and, that the seat of the excito-motory system is in the spinal cord. He further remarks, that volition has an aim or object; while emotion, and the excito-motory function (or vis nervosa of Haller), are aimless on the part of the individual, and frequently opposed to volition.

According to Dr. Hall's earlier papers, chorea was considered an affection of the true spinal system; affording an example of the want of harmony between the cerebral and the true spinal acts. The volition was affirmed to be normal; but the true spinal acts to be abnormal, for want of a precise harmony between the two. This view, however, did not account for the absence of chorea during

sleep for it is one characteristic of the excito-motory function, that it goes on during sleep; so that a disease asserted to be dependent on a morbid condition of that function, ought to be at least as manifest during sleep-when volition, as a disturbing cause, is abstracted-as in the waking state: but the contrary is notoriously the fact; all the symptoms of chorea ceasing as soon as the consciousness of the waking state is suspended. It was necessary, therefore, to seek further for an explanation of this circumstance. “It is well known," says Dr. M. Hall, "that the irregular movements in chorea, and in incipient paralysis agitans, subside during sleep. I was long perplexed to account for this fact. It was only by observing that these movements subside during quiet sleep only, and return during the agitation of dreaming, that I perceived that it is not sleep, but the absence of emotion, to which this effect is to be ascribed;-dreams during sleep having the same effect as emotion in our waking hours." This, then, I take to be his view of the pathology of chorea-that it is a morbid condition of the organ of emotion, which has its seat in the medulla oblongata, and is wholly independent either of the brain or the ganglionic system.

Dr. Babington adds:

"I should define chorea to be a disease characterized by irregular uneontrollable contractions of the voluntary muscles, alternating with their atony, and occurring without pain. I have used the word 'contractions, and have included the atony of the muscles in this definition, because the movements in this disease appear to me to differ essentially from those of convulsions and epilepsy in this, that the stimulus, whatever be its nature, which excites either the whole or a portion of the voluntary muscles to involuntary action, is not more violent in degree than the normal stimulus of the will, or of the excito-motory system; so that movements, almost incessant indeed, but not exaggerated like spasms, are the result. It will illustrate my meaning, to state, that a person in sound health could, at any one moment, perfectly imitate, by an exercise of the will, every movement which he would involuntarily perform if he were the subject of the most aggravated form of pure chorea. Again, there is another circumstance which scems to me to attend the movements in chorea, and which may furnish ground of distinction between this and truly spasmodic seizures. The nerves, in their normal state, are always exercising a certain amount of influence over the muscles; so that where there is antagonism of forces, it is only necessary to remove the one opponent in order to demonstrate that the other is in a state of activity. This being the healthy condition, we have a right to consider the diminution of this activity as a morbid state; for although, from the striking effect which a morbid exaltation of muscular force produces, spasm is more directly brought to the cognizance of our senses than atony, still the latter is no less a really morbid condition than the former. I venture, then, to express my belief, that while, in true convulsions, the muscles, after having been thrown into a spasmodic state, do only return to the normal condition; in chorea, on the contrary, a further diminution of nervous influence occurs; so that the muscles become, in all marked cases, entirely passive and inert in the intervals between their irregular and involuntary actions. This is manifest, from the manner in which the limbs drop from the position into which they have been thus thrown; in which the head, after being tossed to and fro, will fall passively on the shoulders, and from the incapability on the part of the patient to hold any thing in his grasp."

Dr. Babington offers a good account of the history and symptoms of chorea. And his allusion to the exciting causes of the complaint is lucid. If we affirm, he says, that the primary seat of chorea is in the medulla oblongata and spinal marrow, we must at the same time admit that this may be affected through the medium of its connexion with the sensorium on the one hand, and with the ganglionic system on the other. Its exciting causes will thus naturally divide themselves into three kinds; namely, 1st, Those which primarily affect the spinal