elevated temperature: it is only when the animal is disposed to sleep, whether ordinary or hybernating, that the temperature begins to sink. The last proof of the almost total cessation of breathing during hybernation, is the capability of the animal to live for a considerable period in noxious gases, and even under water. Spallanzani narrates an experiment, in which he confined a marmot and a bat for four hours in carbonic acid gas, and yet they lived. Dr. Hall immersed a hedgehog and a bat in water of 41°; the former was kept 22 minutes, the latter 16 minutes, under the surface without any injury to them. Now these animals, when active, are as speedily asphyxiated by drowning as any other of the mammalia; at least, such seems to be the case, according to Dr. Hall's experiments, in which he found that a hedgehog was killed in three minutes, from the time of immersion. Our author, therefore differs from Sir A. Carlisle, and Dr. Edwards, when they assert that "animals of the class mammalia, which hybernate, have at all times a power of subsisting under a confined respiration, which would destroy other animals not having this peculiar habil."

2. Of the Irritability during Hybernation. The very circumstance of the animal's living when deprived of atmospheric air, is an argument that their irritability or tenacity of life must be much increased; and this is powerfully confirmed, by finding that the heart continues to beat regularly for at least 10 hours, after decapitation and the destruction of the spinal marrow. A comparative experiment was performed on a hedgehog in its active condition; the spinal marrow was simply divided at the occiput. The beat of the right ventricle continued upwards of two hours-that of the left one ceased almost immediately; the left auricle was motionless in less than a quarter of an hour, and the right auricle had ceased to beat long before the right ventricle. It has been often asserted that the contractility of the voluntary muscles is impaired during hy

bernation; this, Dr. Hall says, is quite erroneous, and the mistake has arisen from authors confounding the lethargy of hybernation, with the torpor which is induced by extreme cold. We have only suddenly to arouse a bat or a hedgehog from their hybernating state, and we shall find that the former speedily flies about with great activity, and the latter walks about and does not stagger. In short, the phenomena observed are similar to those of awaking from ordinary sleep.

3. Of the Sensibility. Dr. Hall states that all preceding authors have committed a great error, in supposing that the sensibility of animals during hybernation is diminished; in truth, it is quite as perfect as in ordinary sleep; the slightest touch of one of the prickles of a hedgehog is sufficient to arouse it; and the gentlest shake causes a bat to respire. The sensorial functions are, indeed, nearly suspended ; if a hedgehog, in its active state, be thrown into water, it immediately uncoils itself betakes to swimming-in the hybernating state, on the other hand, no fear appears to be excited, and the animal would probably remain still and quiet for a very considerable period, if its sensibility were not acted upon by the contact of the water.

4. Of the Circulation. Dr. Hall, by a nicely-contrived experiment, was enabled to examine the circulation in the wing of the bat, in its state of hybernation; he found that, although the animal did not perceptibly breathe, the circulation continued uninterruptedly; the number of pulsations in the minute was about 28°. All the blood is venous, and the curious fact is, that the left side of the heart, and also the arterial system, are now veno-contractile. This phenomenon is one of the most remarkable in physiology; it accounts for the life of the animal being independent of respiration, and is, in short, the key to the right explanation of the susceptibility of some animals taking on the hybernating state, and of the insusceptibility of the greater number.

5. Of the Digestion. The bat does not

shew any disposition to awake for the purpose of taking food during its continued hybernation; neither are any excretions passed. External warmth, or any excitement, is the only stimulus which arouses it. On the other hand, the hedgehog, if the temperature be about 40° or 45°, awakes every two, three, or four days to take food, and it then returns to its state of lethargy; under similar circumstances, the dormouse awakes daily. Hunger is, therefore, probably the stimulus which induces the animal to awake at intervals.

Having now considered the condition of the leading vital functions during hy bernation, we can be at no loss to perceive the marked difference between this state, and that of torpor from extreme cold. We have seen that the muscles do not become stiffened and incapable of motion-that the nerves are not benumbed and paralysed, and that hybernation is a salutary change, and one conducive to the preservation of life; whereas continued torpor from cold, as is well known, generally proves fatal. Indeed we shall find that, when a hybernating animal is subjected to great cold, without any means of increasing and retaining its warmth, it often remains in a state of activity, while others of the same tribe, which are provided with

wool or straw to make a nest for themselves, speedily become lethargic. It is, therefore, moderate, and not extreme cold, which disposes to true hybernation. During the Winter months, they seek some secure retreat for nests or burrows, or congregate in clusters; and, if the season is unusually severe, many are found to perish from the cold. Let these particulars be, therefore, well remembered, in order that we may not, in future, mistake the phenomena of torpor from cold for those of true hybernation. In one respect only do these two states agree, and that is, in the dangerous and often fatal consequences of over-speedy reviviscence; if the respi. ration of an animal, lethargic from hybernation, be suddenly restored and kept permanently excited, the effect is very often the death of the animal.

Recapitulation. The following conclusions contain the essence of Dr. Hall's observations:

1. The natural sleep of hybernating animals differs greatly, but only in degree, from the sleep of other animals.

2. This sleep passes insensibly into the state of true hybernation, which becomes more and more profound as the blood loses its arterial qualities.

3. The respiration and evolution of heat are nearly suspended during hybernation.

4. The irritability of the heart and arteries is singularly augmented, so that they become veno-contractile.

motility are unimpaired. 5. The sensibility and general muscular

6. The phenomena of true hybernation are very different from those of torpor from cold.

7. Severe cold, like all other causes of

pain, rouses the hybernating animal from state of stupor. its lethargy, and, if continued, induces the

8. The phenomena of hybernation are attributable to the susceptibility of the heart and arteries to be stimulated by venous blood, and to the various organs of the body becoming much more irritable than during the state of the ordinary activity of the animal.-Philosophical Trans

actions.

XXXVII.

gradually diminished. He never exceeded 18 grains at once; sometimes he added small quantities of opium to it, to check the nausea which distresses many patients, and to hasten the "tolerance" of the medicine. It was usually exhibited in an infusion of chamomile and orange leaves, and given by a spoonful at a time, at very short intervals. -Ibid.

The preceding observations are well worthy the attention of every reader. We have given all the pith and substance of M. Bricheteau's memoir.-ED.

XXVIII.

DR. GRAVES ON PERIOSTITIS.* Dr. G. divides periostitis into two kindsdiffused and circumscribed. The former is that which usually terminates in necrosis, and falls to the care of the surgeon; the latter constitutes nodes. It is to the latter affection that Dr. G. limits himself, in a clinical lecture delivered at the Meath Hospital.

Circumscribed periostitis may arise from cold; most commonly from a specific cause, as syphilis, mercury, or scrofula.

It presents some varieties. First, it exists without detachment of the periosteum from the bone. The membrane becomes inflamed and thickened, the bone beneath vascular. There is now pain and tenderness in the part, sometimes with swelling and discoloration of the integuments. The affection becomes chronic, the symptoms rather decline. Then the periosteum becomes more dense, even fibro-cartilaginous. When this change has taken place, Dr. G. thinks it doubtful whether the diseased mass is ever again absorbed. We are not so sure of this. We see now and then, rarely, we admit, the most solid and bony nodes diminish under the influence of mercury. If healthy bone and fibrous tissue admit of absorption, why may not new osseous or fibrous structure?

Lond. Med. and Surg. Journal, Dec. 29th, 1832.

VOL. XVIII. No. 36.

When ossification takes place in a node, the external lamina of the true bone beneath is in process of time absorbed, and, at the same time, a cancellated structure is developed in the node, the two orders of cancelli thus becoming continuous. The tibia of prostitutes are often much disfigured, from irregular bony elevations of this description.

Secondly, periostitis may be attended with detachment from the bone beneath, and of this there are several varieties. The first variety is this. In a space, varying from twenty-four hours to eight or ten days, an elevation appears on some part of a bone, with pain and tenderness on pressure, forming a tumour apparently solid, but, on accurate examination, somewhat elastic.

Soon

a gradual diminution of the pain and swelling occur, the fluid effused under the periosteum is absorbed, and the subjacent bone and periosteum become again united. This process generally occupies some time, but occasionally is more speedy. The tumours which rapidly form and disappear on the scalp are of this nature. The surface of the bone does not die. Usually ulceration of the skin does not occur in this variety; but, if it does, the cure is effected by granulations arising from the vascular surface of the bone. In the second variety, matter is effused beneath the periosteum, the bone affected becomes vascular at a little depth, but the surface is white and dead, and consists of a thin, worm-eaten, cribriform lamella, which, after some time, separates, and opens for itself a passage through the integuments. The cure is effected by granulations from the vascular part of the bone beneath.

Scrofulous periostitis is a simultaneous affection of the bone and periosteum. Sometimes, in vitiated constitutions, the periosteum becomes affected, from ulceration commencing in the skin, as in rupia, ecthyma, &c. In all, except the first species of periostitis described, Dr. G. recommends cutting through the integuments and periosteum, as recommended by Mr. Crampton.

The scrofulous periostitis (node) is attended with milder symptoms-less pain and tenderness-less swelling-and occurs

42

Dissection. The lungs and cavities of the pleure healthy. The pericardium was found to be so closely adherent in all its extent to the heart, as to be separable from it only by the scalpel; the agglutination was firm and ligamentous; there was no appearance of any intermediate membrane, or of bands passing between the two surfaces, for, strictly speaking, there was but one membrane, or in the language of the older pathologists, the pericardium was awanting.

Remarks. The symptoms deemed by Kreysig as characteristic of this disease, viz. the movement forward of the diaphragm and the pulling inward of the left lower ribs synchronously with the alternate actions of the heart, are unsatisfactory and incorrect. Corvisart says that the absence of any strong palpitations, while the other signs of diseased heart exist, may lead one to suspect adhesion of the pericardium.-Ib.

XL.

CASES OF INSANITY, WITH POST-MORTEM APPEARANCES, By Dr. MACROBIN, Aberdeen Lunatic Asylum. WE have selected the following cases from the reports transmitted to us by Dr. Macrobin, and regret that we have been unable to insert the others.-ED.

Case 1. Margaret Panton, æt. 70, from Aberdeen. Admitted 1808.

Sectio Cadaveris, 21st Feb. 1832, 12 Hours after Death.--The calvarium was thin, and its removal was effected with difficulty, in consequence of the very firm adhesion of the dura mater to the inner table, especially along the line of the longitudinal sinus, where the membrane was thickened and vascular; some patches of the membrane were left adhering to the occipital bone. A laceration, which had been produced in effecting this removal, allowed the escape of between four and five ounces of limpid, colourless serum, which had been deposited between the dura mater and arachnoid, and which lay

over the surface of the right hemisphere of the brain; the dura mater was accordingly discerned collapsed, and thrown into folds. Upon reflecting this membrane (which otherwise presented a natural appearance), the whole cerebral substance composing the right hemisphere was discovered greatly compressed, and greatly diminished in bulk.

The convolutions were flattened and pressed together, and over a space of an inch and a half to two inches in diameter, and immediately above the lateral ventricle, they (the convolutions) had entirely disappeared, apparently from absorption, leaving an irregular oval-shaped depression, the base of which consisted of the corpus callosum, the white colour of which was visible under the arachnoid and pia mater, which lined this depression, and which were much thickened, so that a layer of medullary substance, of three or four lines in thickness only, existed between the convex surface of the brain and the right lateral ventricle. There was another similar, but smaller depression or cavity on the surface of the anterior lobe of same hemisphere. In connexion with these appearances, the whole of the cerebral substance had undergone great compression from the presence of the fluid; the whole hemisphere having suffered a diminution to the extent of at least onethird of its ordinary bulk, and being sunk much below the level of the opposite hemisphere. There was no appearance of increased vascularity of the pia mater, and the substance of the brain generally presented a natural consistency and colour, with the exception of some venous congestion, the number of dark bloody points being very numerous.

There was no fluid over the left hemisphere, nor more than usual in either ventricle. Both choroid plexuses were turgid and hydatiform. The apex of the upper lobe of the left lung was tubercular, and the lower lobe of same lung more solid than natural, being without crepitus, and greatly infiltrated with serous fluid; and

there were some traces of recent lymph, causing adhesion between the pleura costalis et pulmonalis. The right lung quite healthy. No disease of the heart or arteries, there being not the least tendency to ossification in them, or any other structure of the body.

Abdominal viscera sound.

The subject of the above appearances, a female in the lower ranks of life, had been confined to the Lunatic Asylum for upwards of 20 years. She had completely lost the use of the left upper extremity, which was quite rigid and bent, from contraction of the flexor muscles of the forearm and fingers. It is understood that she suffered some febrile attack (a "fever" the friends called it) about puberty, which recurred repeatedly, and which at length affected her mental faculties, and that the paralytic affection of the arm occurred about the same time; but little of the history can be relied upon previous to her admission in 1808, since which time she had continued to enjoy pretty good general health. Her insanity was marked by various hallucinations and illusions of the external senses, those of sight, hearing, and common sensation being perverted.

Her memory had also suffered, her memory of events since her attack being quite abolished, though she had a lively recollection of all the circumstances of her life previous to this. She was very loquacious, and highly irritable and ill-natured. The natural functions were performed in health to the last.

Case. 2. David Bruce, æt. 47, from Aberdeenshire. Admitted 1st August, 1831.

Sectio Cadaveris, 16 Hours after Death. 4th March, 1832. Head. At the anterior part of the middle lobe of the right hemisphere, there was observed a space of about an inch square of the cortical substance in the state of distinct ramollissement, being diffluent and broken down, and converted into an ochre-coloured pulp, and which had stained the dura mater which covered it of a bright yellow, the proper membranes of the brain having been removed at this point by the morbid process. A similar change was observed to be going forward, to a

smaller extent, on the convolutions of the anterior lobe. This softening and disorganization was best marked on the surface of the convolutions, diminishing in intensity as it extended inwards, and did not penetrate to the medullary substance.

The arachnoid, over the whole convex surface of the brain, and over the anterior as well as posterior lobes, was greatly thickened, and the pia mater was very vascular, which vascularity extended between the convolutions, and the membrane admitted of being easily removed.

The same membranes covering the base of the brain were not thickened. There was only slight effusion of serum over the surfaces and into the ventricles of the brain, not exceeding 3 ss. in the latter situation.

The subject of the above appearances was a labourer, and had led a sober and industrious life; and, previous to May last (1831,) had exhibited no indications of mental disturbance nor morbid train of thought, though his bodily health had somewhat declined: but for two or three weeks previous to the accession of the maniacal paroxysm (which happened about the middle of May,) he had began to exhibit a change of temper and disposition, being one time gloomy and melancholy, and at another irritable and excited. He continued to labour upwards of two months under violont maniacal delirium, when fatuity supervened, and it was then that he was brought to the asylum (1st Aug. last.)

He was then unable to answer questions; though at times, if the question was repeated, and his attention roused by the speaker, he would seem to comprehend what had been said, for he would labour to give utterance to some words in reply, and probably, after the lapse of a minute, some answer might be obtained, while the words, which seldom amounted to three or four, were uttered slowly and with hesitation, and apparently with difficulty.

His aspect was very vague, and led to the impression that, in general, he did not comprehend what was addressed to him. His memory seemed to be nearly abolished. The pulse was feeble, and slower than natural. He was unwilling to move from