from the peritoneal into the pleural cavities, and consequently there was no hernial sac. On the right side, however, the protrusions were usually sacculated, being covered, either with peritoneum or pleura, or both. The predominance of sacs on the right side, is owing to the following structure: Behind the ensiform cartilage, the diaphragm is imperfect; a triangular opening exists in the musculo-tendinous layer, which opening is divided into two, by a slip of fascia running forward to be attached to the posterior surface of the ensiform cartilage. These two openings are only closed by a serous membrane of the chest on one side, and of the abdomen on the other, consequently this is a favorite point for the protrusion of hernia upward into the chest, and of course a hernia at this point would carry gradually the peritoneum before it, and have a regular sac; whereas, in the other parts of the diaphragm, the hernia is more likely to be a violent rupture, rending an opening at once from the peritoneal to the pleural cavity. If, now, the position of the heart and the two lungs be taken into consideration, it will be readily perceived, that in as much as the right lung comes nearer to the mesial line than the left, at this point, the hernia will nearly always go to the right cavity of the chest. This mechanism explains beautifully the predominance of the saculated form on the right side.

TO BE CONTINUED.

ART. V.-Meteorology.

The subject of Meteorology is one so obviously connected both with Pathology and Hygiene, that the Peninsular Medical and Scientific Society, which was organized in March last, deemed it necessary to take immediate measures to have the Meteorology of the State investigated, recorded, and reported upon. Dr. M. K. Taylor, of Brooklyn, Michigan, was therefore appointed a committee to establish over the State a system of observations for this purpose, and to collect and report the results. No one man can accomplish such an enterprise. He must unite with him many observers in different localities. All those persons, physcians or not, who are willing to assist in making and recording such observations, are earnestly requested to communicate with Dr. Taylor, Brooklyn, Mich. The following memoranda, partly on the same subject, having been omitted in our previous number, for want of room, we subjoin them here.-ED.

Notes of the Thermometer during the winter of 1852-3. By J. C. NORTON, M.D.

TO THE EDITOR OF THE PEN. JOUR. OF MED: Dear Sir-I herewith send you some average results made from my notes of observations on the thermometer during the past winter, which you are at liberty to publish if you see fit.

Rockford, Ill., Lat. 42 deg. 12 min. N., Long. 12 deg. W.

My botanical observations are too numerous to be profitable for publication. I send you, however, a list of plants growing here which I have never seen in those parts of Michigan where I have been.

SELECTIONS.

From the Boston Medical and Surgical Journal

Motive Power of the Blood proved by experiments on four Crocodiles. One brought to life. By SAMUEL A. CARTWRIGHT, M. D., New Orleans, late of Natchez.

Four crocodiles were subjected to vivisection in the court-yard of my office, on the 1st and 6th of the present month. One was nearly ten feet long, another about six and a half feet, and the other two of smaller size.

June 1st, at half past 9 o'clock, I tied the trachea of one of the smaller sized saurians, and turned it loose. At twelve minutes before 10 o'clock, I tied the trachea of another one, and proceeded at once to open the thorax and abdomen, exposing the viscera, even the heart, to view, by opening the pericardium. It was then taken from the table and placed on the floor. The largest crocodile was surrendered to Dr. Dowler, to perform any experiment he might see proper. By this time a number of medical gentlemen had assembled to witness the experiments; viz., Drs. Copes, Nutt, Hale, Wharton, Weatherly, Chaillie, Chappellier, Greenleaf, Prof. Riddell and his brother, and also Messrs. Brenan and Gordon. While the large crocodile was being secured and made fast to the table, the two others, whose traches had been ligated, were moving about as actively as before the operation. Some doubted whether the ligation would kill them at all; and others were of the opinion that the exposure of the viscera and serous membranes of one of them to the action of the air, would prevent the ligation from proving fatal, as oxygen would be absorbed and carbonic acid expelled by the tissues thus exposed. The experiment reported at page 394 of the 46th volume of this Journal, June 16, 1852, where an alligator, nearly dead, revived under the scalpel of the dissector, while the ligature was still around the trachea, had given rise to that opinion; although it was subsequently demonstrated, by attempts at insufflation, that the lungs had been cut by the operator, thus giving egress to the poisonous carbonic acid and ingress to the vivifying oxygen-still the erroneous impression was left on the minds of Dr. Dowler and others, that it was the exposure of the membranes to the air by the dissection which revived the animal. In the present case the viscera and membranes were as extensively exposed to the air as in that instance. I particularly guarded against cutting the lungs or any branches of the bronchial tubes. Both animals, in less than an hour after the ligation of the trachea, were dead. The one whose viscera had been exposed, died as soon as the other. When pinching, burning and piercing the most sensitive parts of the body ceased to cause motion or to produce sensation, the first one operated on was re-placed on the table, and the

viscera of the thorax and abdomen exposed by dissection. An artery was accidentally cut, and a profuse hemorrhage was the consequence. The temperature of the room was 83 deg. The inflating process was then commenced, and some faint evidences of returning vitality manifested themselves; but as the reptile had lost the greater portion of the blood in its body, the very substance I wished to vivify and set in motion by the introduction of fresh air into the lungs, I abandoned the experiment and removed the subject from the table, without regret, intending to make it answer the purposes of another experiment, to prove the error of certain reviewers, who had taken the position, "that alligators were curious animals, and might come to life themselves if let alone." Hence the determination to let this one alone, to prove to sceptics that nothing short of the admission of fresh air into the lungs can restore life in cases of asphyxia or suspended animation. It never came to, or responded to the irritants applied to its nerves, but quickly lost every remaining vestige of life after the insufflation was suspended. Even the irritability of the muscles was destroyed; thus confirming the experiment reported at page 79 of the 47th volume of this Journal, Aug. 26, 1852, where simple ligation of the trachea not only destroyed life, but muscular irritability, by poisoning the blood by the retention of carbonic acid.

The other crocodile, above mentioned, whose trachea had been tied at a quarter before 10 o'clock, and the viscera immediately exposed, was found to be dead, and at 25 minutes before 11 o'clock was replaced upon the table. Various means were used, as pinching, piercing, and burning the most sensitive parts of the body, to extort symptoms of life; and when they failed to have any effect, the inflating process was commenced. After continuing the insufflation of the lungs for some fifteen or twenty minutes, the animal came to life, snapped its jaws, opened its eyes, moved its limbs, and twisted and worked itself when pinched or cut. In the language of a by-stander "it lived again." It continued to live for several hours afterwards. It was brought to life at 11 o'clock. At 3 o'clock, when the company left for dinner, it was still alive, and would dodge the finger when thrust at its eyes, although not touched. Several gentlemen, before leaving, convinced themselves by that and other measures, that the reptile was not only alive, but had its sight, hearing, intelligence and the power of motion restored to it. When the company left, it was the only live crocodile in the room. Both the others had been dead for some time. The first one operated upon had been dead more than four hours-and the one which Dr. Dowler had been experimenting on was also dead, although it was the last one brought on the table.

On the 6th of June I tied the trachea of a female crocodile, about six and a half feet long, and as large around as a common sized man-Drs. Dowler, Copes, Wharton, Chappellier, Reynolds, Greenleaf and Backee being present. When animation became nearly suspended, the viscera were exposed by dissection. On opening the pericardium, the auricle of the heart happened to be pierced. The hemorrhage was profuse. A ligature was put around the slit in the auricle, but before the hemorrhage could be arrested the most of the blood in the body had escaped. Insufflation was tried, but it had very little ostensive effect. It excited the heart into action, and restored some degree of motion and sensibility; but

it restored and preserved an amount of vitality sufficient to enable Dr. Dowler, to whom I resigned the half-dead female saurian, to re-produce those astonishing phenomena of the nervous system, which he has heretofore made known to the scientific world. They are of a nature to make a Nilotic ruin, a perfect chaos, of the main foundation of physiology and pshychology since the days of Moses. In the report of the experiment on the battle-ground crocodile, published Aug. 25, 1852, in the 47th volume of this Journal, it is stated that after tying the trachea, the animal died, and that Dr. Dowler, with fire, hooks and forceps, failed to produce a single nervous phenomenon he had been accustomed to show. But in this instance, a sufficient quantum of vitality remained and was kept up by the inflation, to enable him to verify to the bystanders nearly the whole of those remarkable facts he has heretofore reported in his "Contributions to Physiology." He proved with the half-dead reptile, as also with the ten foot crocodile on the 1st of June, what he had frequently proved before, viz., that sensibility, motion, the will and intelligence, continue to be manifested in the body after it has been cut off from the brain and spinal marrow; that pinching the distal portion of any divided nerve will cause motion and sensation in the part to which it is distributed; and that the same phenomena will continue to occur as the nerve is followed downward toward the part to which it is distributed. These experiments with the crocodile prove the fallacy of those dogmas, which have so long made physiology and psychology the most hypothetical, changeable and non-progressive of all the sciences. Until cut loose from the unsound learning of the dark ages, those noble sciences cannot be made to perform their proper part on the arena of practical utility. The hypotheses to which they are chained, make the cerebral system the subjective or the me, and the blood the objective or the not me. To reach the brain, the supposed seat of the subjectivity, recourse has been had to the supposition, that impressions from without are conveyed by a subtle fluid, oscillations or other means, through the nerves to the brain-the supposed exclusive residence of the mind. The latter is supposed to give its commands, which are conveyed by the same or another set of nerves to the muscles and to the different organs of the body, ordering muscular motions to be performed and pain or pleasure to be felt. Another hypothesis pre-supposes that the chief motive power of the blood is derived from the mechanical propulsion effected by the contraction of a muscle, called the heart. There are more than three millions of species of animals destitute of such an organ, and even in mammals the heart and arteries are of subsequent formation to some other structures of the body abundantly furnished with nutritive fluids. While such unsound doctrines (which need only be stated to carry their refutation upon their face,) are received as fundamental truths in physiology and psychology, it will be vain to expect that these sciences can make any progress in the field of utility and practical operations. While such errors prevail, the phenomena attributed to mesmerism, table-moving and spirit rapping, will continue to confound the wisdom of the learned, and to lead the ignorant and credulous into every species of ridiculous extravagance. Such is the natural tendency of the popular mind, when men of science are driven to the subterfuge of denying phenomena clearly demonstrable-not for the