and more satisfactory explanation of this subject based upon physiologi cal and therapeutic philosophy, to which, in all the examinations I have given the question, I have not seen the least allusion. And in order that you may comprehend the exact import of the explanation which I have to offer, you will pardon me for refreshing your minds with the physiological demonstration of the respiratory problem. The first inspiratory act of the child at its birth is brought about by the sudden change in its dynamic condition; having been imbedded in a bag of tepid water, which was sedative to its nervous system, the sensory nerves of the entire integument, suddenly brought under the stimulus of a lower temperature, and other unaccustomed stimuli, the centres of the arc thus roused up answer to the stimulation they have received, by sending a vis nervosa along the motor nerves to the muscular system, and, in common with other muscles, the diaphragm and other inspiratory muscles are contracted, which enlarges the different diameters of the thoracic cavity, and thus, by the vacuum which is being formed, invites the air to fill the bronchial tubes, and diverts the current of blood from the ductus arteriosus into the pulmonary arteries, capillaries and veins. This is a pure excito-motory phenomena, with the sensory pole of the arc in the general integument, the motor pole in the muscular system, and the central link in the spinal cord. But this is not the ordinary respiratory nervous arc. Each after expiration and inspiration is confined to a more specific respiratory arc. The sensory pole is changed from the general integument to the mucous membrane of the bronchial tubes and air vesicles, and consists in the distribution of the pulmonary portion of the pneumogastric nerve, the phrenic and intercostal, the motor pole, and the medulla oblongata, the central ganglia. Each act of inspiration is stimulated by the complemental or residual air, which is a mixture containing four and a third per cent. of carbonic acid. The stimulus of this mixture, and possibly that of the venous capillaries, is received by the sensory extremities of the pulmonary pneumogastric. And thus it is perceived that each respiratory act is a purely automatic phenomenon, through a special excito-motory respiratory arc. The regular respiratory phenomena are modified by volition, sensation, emotion. and ideation by commissural connection between the medulla oblongata and the encephalic ganglia; and on the other hand with the excitomotory phenomena of each segment of the spinal cord, thus establishing a grand solidarite between the different centres of the cerebro-spinal system. The society will pardon me for this apparent digression, when they reflect that in studying the manner by which an agent produces death by suspending the function of a great organ, we must ascertain what event fails in the chain of its phenomena. It must be remembered, too, that the vapor of chloroform has a local as well as a general anæsthetic effect-if applied for a few seconds to any part of the integument, all sensibility in it is lost-it ceases to appreciate stimulation of any kind, even from rude contact, and, though it was the seat of morbid sensibility, is lulled into quiet repose. The local anesthesia is one of the most valuable of the virtues of chloroform, but it is to this effect upon the mucous membrane of the air passages, bronchial tubes and air

vesicles, that its great danger is due. You will call to mind what we stated in the preceding part of this paper in reference to the residual air, complemental air, breathing air, and ærial capacity of the lungs ; and how these different airs were substituted by the vapor of chloroform, and that we arrived at the conclusion that the lungs might be filled with two hundred and eighty cubic inches of pure chloroform vapor, which by endosmosis is penetrating every part of the parenchyma of the lungs. Now the obvious consequence is that we have a local anesthesia of the sensory pole of the respiratory excito-motory arc, and as a result of this an immediate suspension of the alternate contractions of those muscles in which exist the motor pole of the same arc, and whose work it is to enlarge and diminish the thoracic cavity. The consequence is just the same as though both pneumogastric nerves had suffered section at the same instant. When there is section of both the pneumogastric nerves, the number of respirations sinks to about two or three to the minute, and the animal soon dies. The power which keeps up this imperfect respiration is due to sensational, volitional, and emotional activity. If we isolate the medulla oblongata from the nervous centres which give expression to these states of being, and thus deprive the flagging respiratory function of their aid, section of the pneumogastrics would prove immediately fatal. This is effectually accomplished by anæsthesia of the thalami optici, the great centres of sensation. For if they fail to recognize the inconvenience of the partially suspended respiration, volition fails to come to the rescue. Much more does this fact hold good if all the encephalic centres are under the effects of chloroform. But if artificial respiration can be kept up for a time, this local anesthesia will pass off, and the respiratory excito-motory arc be restored to its integrity. When we come to analyze the two explanations I have given of the manner in which chloroform produces death, we find in both cases the respiratory muscles cease to act-in the one from anesthesia of the medulla oblongata, the central link, in the other of the sensory pole of the respiratory excito-motory arc. Now my own opinion is that the latter is the fruitful source of danger and of death, and I am further sustained in this conclusion from the fact that we have no well-authenticated case of death recorded from the anesthetic effects of chloroform when it is swallowed into the stomach, even though very large quantities have been taken. In two cases where over an ounce had been taken in each, heavy and profound stupor supervened, attended with stertorous breathing; no chloroform was found in the contents of the stomach after using the stomach-pump, which implies that it was all absorbed; it was however detected in expiration. A case is reported in the Edinburgh Monthly Journal of Medical Science for January, 1852, where the subject was intoxicated with alcohol, and took several ounces of chloroform into his stomach at once. He died in thirty hours from a gradually increasing difficulty of respiration, attributed to the combined effects of chloroform and alcohol. A post-mortem examination discovered only heavy congestion of the lungs. This is the great pathological feature in death from chloroform inhalation, as we shall soon see. Thus we preceive that very large quantities may be circulated through the blood with great impunity

when it gets access to it through the stomach, which goes far to disprove the idea that the cause of death is centric, or anæsthesia of the medulla oblongata.

We remarked in a previous part of this paper, that death rarely occurred during an operation that could be attributed purely to the chloroform, and that there was no fatal case recorded when giving during parturition. Now these facts furnish us with further proof of the position we have taken. During the progress of an operation, the rough stimulation of the afferent nerves not only rouses the segment of the spinal cord in which they terminate to automatic action, but all the other segments which hold commissural connection with it, including the medulla oblongata. This solidarite of the spinal cord, which gives rise to the first inspiratory effort of the new-born infant, now furnishes some aid to the inspiratory efforts, when the sensory pole of the respiratory excito-motory arc is impressed with anesthesia. The seat of the operation for the time becomes the sensory pole of this arc. This is strictly in accordance with the anatomical and physiological facts advanced in previous parts of this paper. Every one who has watched the progress of a case of labor, has observed to what a great extent the respiratory acts are influenced and modified by the pains. Indeed, we see diaphragm and other respiratory muscles controlled for the time by a different stimulation to that which ordinarily governs. The sensory pole is here located at the neck of the womb and perineum, and, by the commissural solidarite of the segments of the spinal marrow and of the medulla oblongata, in common with other segments, it controls the respiratory acts, and this will be the case even though the sensory pole of the true respiratory excito-motory arc is profoundly dormant from the effects of chloroform. Now if there was centric anesthesia of the medulla oblongata, these phenomena could not follow, and death would be inevitable in every case. This substitution of the sensory pole, which is one of the conservative laws of our economy, would in this case be entirely unavailable.

It only remains for me to make a few remarks in reference to the condition of the lungs as revealed by post-mortem examinations. If the patient dies from the effects of chloroform, whether the anesthesia be at the medulla oblongata or at the sensory pole, the lungs will invariably be in a state of congestion or apoplexy; precisely such a condition as results from drowning or suffocation, or section of both pneumogastric nerves it is a complete asphyxia. That condition which is entailed by failure of the heart, on account of failure of the respiratory phenomena, from whatever cause, is a true asphyxia. Apnoea gives rise to asphyxia. The forces of the circulation which fail first, belong to the pulmonary apparatus. 1st. The suction power exerted in consequence of an enlargement of the thoracic cavity during inspiration. 2d. The pulmonary capillary force arising out of the affinity between the blood and oxygen; the oxygen having been cut off by the manner of breathing the chloroform vapor, and also by a failure of the respiratory muscles to expand the thoracic cavity. Now the heart continuing to act, with a failure of these two forces, will necessarily entail apoplexy or capillary congestion of the lungs; a failure of the capillary force

of the circulation in any organ will produce stagnation and congestion in it.

The great indication of treatment in these cases is to keep up artificial respiration until the anæsthesia shall pass off. Thus the chloroform is pumped out of the pulmonary air-passages, and oxygen supplied to the blood. If this can be instituted before the heart ceases to pulsate, a favorable result is to be confidently anticipated. The capillary stagnation begins to clear up, from a restoration of the conditions which are essential to the integrity of the two forces which were lost. The means by which this desirable result is to be accomplished, are, 1st. Powerful stimulation of the integument, thus to rouse up the spinal cord, and, by the solidarite which links them all into unity, excite the medulla oblongata to call the respiratory muscles into action. This resource should never be neglected; immunity from danger in parturition teaches us its value; still it is not always that it can be made available, particularly when the vesicular substance of the cord is at all impressed with the sedative effect of chloroform. In connection with other stimulation, cold and warm water should be alternately dashed by the bucketful upon the surface of the body. This is a powerful stimulus to rouse up the nervous centres. The second resource to keep up respiration is the "ready method" of Marshall Hall, which is purely a mechanical means for expanding and contracting the thoracic cavity, and is therefore always available, and fully sufficient for any emergency, if instituted before the heart entirely ceases to beat, and all the forces of the circulation have suspended their work.

ABSTRACT OF THE PROCEEDINGS OF THE NASHVILLE MEDICAL SOCIETY.

THE third meeting of the Nashville Medical Society was held at the office of Drs. Foster and Blackie, on Wednesday evening, August 4, 1858; the President, Dr. A. H. Buchanan, in the chair, and Dr. R. C. Foster, in the absence of Dr. Blackie, at the Secretary's table.

The following gentlemen were elected members: Dr. Robert Martin, Dr. C. L. Lewis, Dr. J. W. Hoyte, Dr. H. M. Compton, Dr. J. M. Kercheval, Dr. T. L. Maddin, Dr. D. F. Wright.

Dr. A. H. Buchanan read a paper on "Reduction of Dislocation of the Femur by Manipulation," giving an account of his treatment of three cases after this mode. The paper was requested for publication.

Dr. Callender gave a verbal account of a case of hip-joint affection in a girl eight years of age, a patient in the City Hospital. The joint was almost immovable, with considerable tumefaction over its seat: the thigh was flexed on the body, and the leg, from stiffness of the kneejoint, was incapable of extension on the thigh. The previous history of the case could not be obtained, nor did it appear, on inquiry, that any recent violence had been inflicted. The patient was evidently scrofulous,

yet the acute character of the case forbade the conclusion that there had been scrofulous destruction of the joint. She was the subject of fever, to which remedies were addressed, and an application of a liniment of olive oil, spirits of ammonia, and tincture of iodine, directed for the affected joint. Dr. C. promised further notes upon the progress of the case at the next meeting.

Dr. G. A. J. Mayfield desired to know the experience of members in the use of lemon juice in the treatment of rheumatism. His want of success had suggested the inquiry. After thorough trial, he was not inclined to recommend or use it again.

Dr. Callender had used it in two cases with contradictory results: in the first case without apparent benefit, and in a second case, after two or three weeks' use, he was led to suspect a syphilitic origin of the affection, and substituted the iodide of potassium for it, with good results. The patient was again placed on the use of lemon-juice, with decided benefit, and ultimately complete relief.

Dr. Hoyte had witnessed beneficial effects, in several cases, from the use of cider.

Dr. Martin related the history of an interesting case of placenta prævia, which he was requested to prepare for publication.

Dr. Callender inquired for information as to the degree of success which the members present had obtained in producing the vaccine disease during the late visitation of small-pox to the city. The frequency of failure in his own experience, even with accredited matter, had suggested the inquiry.

Upon this point several members spoke, most of whom had met with similar experience to that of Dr. C. Others, however, had been quite successful, and were disposed to charge failures to imperfect matter.

Dr. Martin discussed the question of necessity for re-vaccination. He related his experience at some length, and stated that it was his practice to continue the introduction of the matter at different points, on successive occasions, until its insertion failed to produce a proper pustule. He questioned very much the protective power of a single insertion of the matter, whatever might be the history of its progress, or the character of the resulting cicatrix.

An interesting discussion was elicited by the question, in which Drs. G. A. J. Mayfield, A. H. Buchanan, Carrow, Hoyte, and S. S. Mayfield participated.

Dr. S. S. Mayfield narrated a case of a large collection of pus in the anterior mediastinum, resulting from a blow on the sternum. A similar injury being inflicted in a subsequent case, the physician in attendance, profiting by the result of the post mortem examination in the previous case, trepanned the sternum, and gave outlet to a large quantity of pus; after which the patient recovered.

Under a resolution of Dr. Foster, Dr. C. L. Lewis was appointed to report at the next meeting upon the sanitary condition of the city, and also the mortuary report for the month.

The Society adjourned to meet on the first Wednesday in September, at the office of Drs. Foster and Blackie.