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NORFOLK AND NORWICH HOSPITAL.
HOSPITAL MEDICINE AND SURGERY.
311
Patting in a match he attempted to "pull a ball to leg," butThe temperature varied from 100° to 101°, the respiration the ball, instead of travelling to that vaguely-defined district, was 20, and the pulse ranged from 70 to 80. The pupils still pin-point in character. She lay on her back unfortunately landed on his own oral region. On examination the right side of his mouth was found to be very in a state of absolute flaccidity, all four limbs being swollen and contused and there was considerable hasmor- motionless and the arms lying by the sides. Costal respirarhage. He was able to open his mouth with some difficulty, tion was quite absent. There were no reflexes in the and it was then seen that the cricket-ball had fractured his lower limbs. There was entire loss of sensation from just right canine and lateral incisor teeth, breaking them off below the level of the clavicles downwards, but the exact flush with the gum. The fragments of teeth had been limiting line could not be defined owing to the patient’s dull driven with considerable force into the lingual muscles, the mental condition. It was evident, however, that the skin points of entry being near the frasnum, the incisor fragment area supplied by the fifth cervical root was quite devoid of being forced out on the dorsum and easily extracted, leaving sensation and that the anaesthesia extended from this region a punctured wound through the tongue, along which the probe downwards. The catheter had to be used, as there was .easily passed from the sublingual to the dorsal surface. The retention of urine and the bowels did not act unless canine tooth, however, had made a channel for itself extending purgatives or enemata were given. The urine contained from the attachment of the frænum into the muscular tissue, neither albumin nor sugar. On the 8th the general condition and could be felt embedded in the tongue near the middle and the state of the temperature, pulse, and respiration line opposite the last molar tooth of the same side, and the remained the same. The plantar reflexes had re-appeared, probe was passed one inch and three-quarters before it the right being better marked than the left. In the reached the foreign body. Pressure and manipulation with evening of the 9th she was not so well. The temperature the finger failed to remove it, so, having applied a spray had been rising all day, so that at 8 P.M. it was 105° in the of ethyl chloride along the track of the tooth it was rectum; the pulse was 92, and the respiration was 40 and grasped by dressing forceps and pulled out by the route shallow. She was more comatose and could not be roused at by which it had entered. The tongue was considerably all. There was complete flaccidity. No reflexes, tendon or lacerated, but no artery of any importance was injured, plantar, could be elicited. The patient died at 6.30 A M. and rinsing the mouth with iced water and, afterwards, on the llth, having gradually sunk since the 9th. The frequent ablutions with a weak permanganate solution, temperature had continued rising, so that two hours before together with abstention from all solid and hot foods, death it was 108° in the rectum, and ten minutes after death, resulted in a rapid recovery, and, excepting a little soreness, 109.2°. The pulse reached 100 for the first time on the organ has now quite healed. The rarity of this form of Feb. 10th. accident is my excuse for reporting the casualty. Necropsy.- A post-mortem examination was made at P.M. on the day of the patient’s death. The fracture of 4 30 W. Acton, the skull in connexion with the wound on the left side of the forehead was found to be two inches long, and it passed obliquely down through the anterior part of the temporal fossa into the anterior fossa of the skull base. There was no depression of bone, laceration of the OF brain or haemorrhage on its surface. There was a good deal of cerebro-spinal fluid in the ventricles, and the cut cerebral surface appeared to be more moist than usual. On BRITISH AND FOREIGN. exposing the cervical spine from behind, the column appeared to be normal and even after removal of the laminas and Nulla autem est alia pro certo noscendi via, nisi quamplurimas et division of the theca the spinal cord looked perfectly morborum et dissectionum historias, tum aliorum tum proprias healthy, and there was an entire absence of meningeal Mllectas habere, et inter se comparare.-MORGAGNI De Sed. et Caus, heamorrhage. On passing the finger down the cord, however, Morb., lib. iv. Prooemium. a portion opposite the upper border of the fifth cervical vertebra felt quite soft, as if pulped. The cord having been NORFOLK AND NORWICH HOSPITAL. removed and divided vertically in the sagittal pane, a A CASE OF TRAUMATIC HÆMATOMYELIA; NECROPSY; hasmatomyelia involving its central parts, was seen to be REMARKS. present opposite the bodies of the third, fourth, and fifth vertebras inclusive, and of the form shown in the illustration. (Under the care of Mr. C. WILLIAMS.) THE very definite symptoms to which a hæmatomyelia gives rise when uncomplicated by any other injury of the spinal cord enable a diagnosis to be made of the exact seat and character of the lesion. In the following case careful observation made the diagnosis certain and effectually prevented any idea of laminectomy, which could have been of no service. For the notes we are indebted to Mr. H. A. Ballance, house surgeon. A woman, aged seventy years, was admitted into the Norfolk and Norwich Hospital at 9 A.M. on Feb. 3rd, 1897, having at ’7.15 A.M. been found in an unconscious condition at the foot of a flight of nine stairs. On admission the patient was quite unconscious; the pulse was 64 and the respiration The pupils were very conwas 16. There was no stertor. tracted and equal, and showed no reaction to light. The kneejerks were present. The breathing was solely diaphragmatic. There was a cut on the left side of the forehead about an inch vertically above the outer canthus and two-thirds of an inch long, exposing the pericranium. A fissured fracture could be felt at the bottom of this wound going obliquely downwards and inwards. There was, in addition, a scalp wound one and a half inches long at the back of the right parietal bone down to the pericranium, but the bone was not fractured. There was no irregularity about the cervical spine. Towards the evening of the day of admission the patient roused up a little, but not sufficiently to talk. There was no sickness, the right arm and leg were rather rigid, and the knee-jerk and plantar reflex were much better marked on that side. The left side of the body was quite flaccid. The breathing was rather noisy; the pulse was 56 and regular ; and the rectal temperature, which on admission was 96° F., rose to 99. 4°. On the 6th the patient remained in much the same Longitudinal sagittal section of the cervical spinal cord, condition and bad roused sufficiently to say ’.No," 11 Yes," showing the hæmatamyelic cavity in the centre and the and ’’ What," but she did not answer questions connectedly. levels ot the cervical nerve roots.
remained
_________
A Mirror
HOSPITAL
PRACTICE,
-
REVIEWS AND NOTICES OF BOOKS.
312
cavity was filled with broken-down blood-clot, the spinal being softened around it. It measured one and threequarter inches vertically and tailed off above and below along the central canal. The largest part of the cavity was opposite the upper border of the fifth cervical vertebra and the fifth nerve root. The upper tailed extremity reached to the level of the second nerve root. Posteriorly the layer of nervous matter bounding the cavity measured one-twentieth of an inch in thickness and anteriorly one-eighth of an inch. The disorganisation encroached more into the right than the left lateral region of the cord. The level of the crush was oblique, as shown in the figure, and exactly opposite the fifth nerve root. On examination of the spine the posterior common ligament was seen to be intact, but the anterior was ruptured opposite the body of the fifth vertebra, which was horizontally fractured at quite its upper part, only a scale of bone having been detached and remaining adherent This cord
to the disc between the fourth and fifth bodies. There was fracture of the articular processes. The lungs were well
no
through and showed no excess of fluid in the was singular considering that the breathing had been solely diaphragmatic for eight days. The other organs were healthy. Remarks by Mt. BALLANCE.-The case is interesting both from the comparative rarity of hasmatomyelia and from the typical symptoms of injury of the cervical cord that were present. The level of the injury was easily diagnosed during life. It was evident that the fifth cervical root had not escaped because of the cutaneous anaesthesia and the aerated all
tubes ; this
paralysis of
the deltoid group of muscles, and that the intact because of the persistence of diaphragbreathing. From the absence of the irritative symptoms commonly met with in hæmorrhage into the meninges it was concluded that the damage was probably limited to the cord itself. The contraction of the pupil and the slow pulse, due, as is well known, to the paralysis of the pupil dilator and cardio-accelerator fibres respectively in their course down the spinal cord to the upper dorsal region, were very noticeable. The exact nature of the injury was dislocation with recoil, the upper four cervical vertebra3 with a part of the fifth having passed forwards on those below them and then sprung back again into their former position, bruising the cord during the process. The situation of the injury in the present case entirely accords with Thorburn’s experience. He states1 that traumatic hsematomyelia usually occurs opposite the fourth, fifth, and sixth cervical vertebrae, and that he has not met with a single case in the dorsal or lumbar regions, a circumstance which he adduces to prove that this form of injury is due to dislocation with recoil, and not to what is vaguely called concussion. Necropsies are very uncommon in this form of hasmatomyelia, as the majority of cases recover. It is to be regretted that this I, patient also sustained a head injury, as otherwise a much ’’i more detailed clinical picture might have been obtained.
fourth matic
was
Reviews The
and
and
Notices of Books. the Cerebral Circulation
Physiology Pathology of Research. HILL,Surgeons M.B.Lond.,of Experimental By LEONARD HunterianProfessor, Professor, Royal Royal College College ofSurgeons -England. Hunterian
: an
of of London : J. and A. Churchill. 1896. Price 12s. THE profound and exhaustive researches upon the cerebral circulation which Dr. Leonard Hill expounded in his Hunterian Lectures for 1896 did much to throw light upon a question that is amongst the most difficult for the physiologist to determine. The re-publication of these lectures in the form here presented will therefore be heartily welcomed, for in them the reader is led step by step towards the explanation of the phenomena of the pathological states of ansemia and compression. The conditions under which the circulation is carried on within the closed cavity of the cranium are not to be explained on anatomical grounds or even deduced from clinical observation. They can only be it is because the experiments and investigated by experiment, carried out for this purpose by the author of this work were
1 Surgery of the Spinal Cord. By William Thorburn.
1889.
skilfully planned and so well adapted to discover the actual conditions that they have been so fruitful. For there is no. question that these physiological researches have led to a. very material change in the point of view from which the phenomena of cerebral anæmia and compression must be regarded. Commencing with the study of the movementsof the brain, cardiac and respiratory, Dr. Hill passes te consider the rôle of the cerebro-spinal fluid, establishing the important fact that in normal states the tension of this fluid is equal to that of the venous pressure. He shows that. the subdural space is physiologically one with the subarachnoid, and that fluid can pass readily from one to the other-a fact which, though anatomically disputed, yet is confirmed by the teachings of pathology. It is instruc. tive to learn that withdrawal of this fluid is at oncefollowed by serous transudation from the blood, and that it is impossible for any increase of the cerebral tension to be transmitted by the cerebro-spinal fluid owing to the tendency to equilibrium between the intra. Dr. Hill also shows that venous and subarachnoid pressure. it is possible to irrigate the brain and spinal cord with ease, his final conclusion to this section being the suggestion "that in such a pathological condition as meningitis irrigation of the meninges might be employed." He addsr ’’ ’’The operation could be as easily and safely carried out as that of irrigation of the peritoneum." The next section deals with the cerebral circulation. Whilst confirming the. general truth of the Monro-Kellie doctrine that the volume of blood in the brain is almost invariably constant, Dr. Hill, by means of most carefully devised experiments, has studied the relations of the intra-cranial circulation. to that of the general circulation. In some respects his results run counter to those of other experimenters, but he gives good reasons for such divergencies,. and affords much matter for thought and inference. One interesting outcome of this research is the evidencethat the circulation within the skull is uncontrolled vaso-motor nerves, but that it is influenced solely by the variations in the general arterial or venous pressure. In so far as this is under any nervous control, it is through the splanchnic nerves that the cerebral circulation is to be. modified, the circulation being accelerated by a rise in arterial pressure and slackened by a fall in that pressure. Owing to the conditions within the skull it is not possible for the intracranial pressure to be more than momentarily raised above that of the cerebral venous pressure. "The cerebral circulation passively follows every change in the general circulation. Every change in the position of an animal from the influence of gravity on the vascular system affects, the cerebral circulation. Every variation in respiration and’ every muscular movement is followed by passive changes in the circulation of the brain. Every heart-beat and every. respiratory undulation is exhibited on the tracings of the cerebral venous or intracranial pressures. Compression of’ the jugulars or the abdomen causes a marked rise in cerebral venous pressure, and muscular movements of the neck by pressure on the jugular veins are sufficient to affect the cerebral circulation. Every stimulus that enters the’ organism and affects the general vaso-motor centre produces a passive effect on the cerebral circulation. Each pleasurable emotion raises the general blood pressure and increases the blood-flow through the brain, and each, painful emotion brings about the opposite result. It is by means of the splanchnic area that the bloodsupply to the brain is controlled"(p. 74). This passage illustrates the prime fact learnt by this researchnamely, the close dependence of the circulation within the skull upon the conditions obtaining in the body generally, and at the same time affords physiological reason for facts of daily experience. A section is devoted to the discussion of the influence of the force of gravity on the so
by
311
Patting in a match he attempted to "pull a ball to leg," butThe temperature varied from 100° to 101°, the respiration the ball, instead of travelling to that vaguely-defined district, was 20, and the pulse ranged from 70 to 80. The pupils still pin-point in character. She lay on her back unfortunately landed on his own oral region. On examination the right side of his mouth was found to be very in a state of absolute flaccidity, all four limbs being swollen and contused and there was considerable hasmor- motionless and the arms lying by the sides. Costal respirarhage. He was able to open his mouth with some difficulty, tion was quite absent. There were no reflexes in the and it was then seen that the cricket-ball had fractured his lower limbs. There was entire loss of sensation from just right canine and lateral incisor teeth, breaking them off below the level of the clavicles downwards, but the exact flush with the gum. The fragments of teeth had been limiting line could not be defined owing to the patient’s dull driven with considerable force into the lingual muscles, the mental condition. It was evident, however, that the skin points of entry being near the frasnum, the incisor fragment area supplied by the fifth cervical root was quite devoid of being forced out on the dorsum and easily extracted, leaving sensation and that the anaesthesia extended from this region a punctured wound through the tongue, along which the probe downwards. The catheter had to be used, as there was .easily passed from the sublingual to the dorsal surface. The retention of urine and the bowels did not act unless canine tooth, however, had made a channel for itself extending purgatives or enemata were given. The urine contained from the attachment of the frænum into the muscular tissue, neither albumin nor sugar. On the 8th the general condition and could be felt embedded in the tongue near the middle and the state of the temperature, pulse, and respiration line opposite the last molar tooth of the same side, and the remained the same. The plantar reflexes had re-appeared, probe was passed one inch and three-quarters before it the right being better marked than the left. In the reached the foreign body. Pressure and manipulation with evening of the 9th she was not so well. The temperature the finger failed to remove it, so, having applied a spray had been rising all day, so that at 8 P.M. it was 105° in the of ethyl chloride along the track of the tooth it was rectum; the pulse was 92, and the respiration was 40 and grasped by dressing forceps and pulled out by the route shallow. She was more comatose and could not be roused at by which it had entered. The tongue was considerably all. There was complete flaccidity. No reflexes, tendon or lacerated, but no artery of any importance was injured, plantar, could be elicited. The patient died at 6.30 A M. and rinsing the mouth with iced water and, afterwards, on the llth, having gradually sunk since the 9th. The frequent ablutions with a weak permanganate solution, temperature had continued rising, so that two hours before together with abstention from all solid and hot foods, death it was 108° in the rectum, and ten minutes after death, resulted in a rapid recovery, and, excepting a little soreness, 109.2°. The pulse reached 100 for the first time on the organ has now quite healed. The rarity of this form of Feb. 10th. accident is my excuse for reporting the casualty. Necropsy.- A post-mortem examination was made at P.M. on the day of the patient’s death. The fracture of 4 30 W. Acton, the skull in connexion with the wound on the left side of the forehead was found to be two inches long, and it passed obliquely down through the anterior part of the temporal fossa into the anterior fossa of the skull base. There was no depression of bone, laceration of the OF brain or haemorrhage on its surface. There was a good deal of cerebro-spinal fluid in the ventricles, and the cut cerebral surface appeared to be more moist than usual. On BRITISH AND FOREIGN. exposing the cervical spine from behind, the column appeared to be normal and even after removal of the laminas and Nulla autem est alia pro certo noscendi via, nisi quamplurimas et division of the theca the spinal cord looked perfectly morborum et dissectionum historias, tum aliorum tum proprias healthy, and there was an entire absence of meningeal Mllectas habere, et inter se comparare.-MORGAGNI De Sed. et Caus, heamorrhage. On passing the finger down the cord, however, Morb., lib. iv. Prooemium. a portion opposite the upper border of the fifth cervical vertebra felt quite soft, as if pulped. The cord having been NORFOLK AND NORWICH HOSPITAL. removed and divided vertically in the sagittal pane, a A CASE OF TRAUMATIC HÆMATOMYELIA; NECROPSY; hasmatomyelia involving its central parts, was seen to be REMARKS. present opposite the bodies of the third, fourth, and fifth vertebras inclusive, and of the form shown in the illustration. (Under the care of Mr. C. WILLIAMS.) THE very definite symptoms to which a hæmatomyelia gives rise when uncomplicated by any other injury of the spinal cord enable a diagnosis to be made of the exact seat and character of the lesion. In the following case careful observation made the diagnosis certain and effectually prevented any idea of laminectomy, which could have been of no service. For the notes we are indebted to Mr. H. A. Ballance, house surgeon. A woman, aged seventy years, was admitted into the Norfolk and Norwich Hospital at 9 A.M. on Feb. 3rd, 1897, having at ’7.15 A.M. been found in an unconscious condition at the foot of a flight of nine stairs. On admission the patient was quite unconscious; the pulse was 64 and the respiration The pupils were very conwas 16. There was no stertor. tracted and equal, and showed no reaction to light. The kneejerks were present. The breathing was solely diaphragmatic. There was a cut on the left side of the forehead about an inch vertically above the outer canthus and two-thirds of an inch long, exposing the pericranium. A fissured fracture could be felt at the bottom of this wound going obliquely downwards and inwards. There was, in addition, a scalp wound one and a half inches long at the back of the right parietal bone down to the pericranium, but the bone was not fractured. There was no irregularity about the cervical spine. Towards the evening of the day of admission the patient roused up a little, but not sufficiently to talk. There was no sickness, the right arm and leg were rather rigid, and the knee-jerk and plantar reflex were much better marked on that side. The left side of the body was quite flaccid. The breathing was rather noisy; the pulse was 56 and regular ; and the rectal temperature, which on admission was 96° F., rose to 99. 4°. On the 6th the patient remained in much the same Longitudinal sagittal section of the cervical spinal cord, condition and bad roused sufficiently to say ’.No," 11 Yes," showing the hæmatamyelic cavity in the centre and the and ’’ What," but she did not answer questions connectedly. levels ot the cervical nerve roots.
remained
_________
A Mirror
HOSPITAL
PRACTICE,
-
REVIEWS AND NOTICES OF BOOKS.
312
cavity was filled with broken-down blood-clot, the spinal being softened around it. It measured one and threequarter inches vertically and tailed off above and below along the central canal. The largest part of the cavity was opposite the upper border of the fifth cervical vertebra and the fifth nerve root. The upper tailed extremity reached to the level of the second nerve root. Posteriorly the layer of nervous matter bounding the cavity measured one-twentieth of an inch in thickness and anteriorly one-eighth of an inch. The disorganisation encroached more into the right than the left lateral region of the cord. The level of the crush was oblique, as shown in the figure, and exactly opposite the fifth nerve root. On examination of the spine the posterior common ligament was seen to be intact, but the anterior was ruptured opposite the body of the fifth vertebra, which was horizontally fractured at quite its upper part, only a scale of bone having been detached and remaining adherent This cord
to the disc between the fourth and fifth bodies. There was fracture of the articular processes. The lungs were well
no
through and showed no excess of fluid in the was singular considering that the breathing had been solely diaphragmatic for eight days. The other organs were healthy. Remarks by Mt. BALLANCE.-The case is interesting both from the comparative rarity of hasmatomyelia and from the typical symptoms of injury of the cervical cord that were present. The level of the injury was easily diagnosed during life. It was evident that the fifth cervical root had not escaped because of the cutaneous anaesthesia and the aerated all
tubes ; this
paralysis of
the deltoid group of muscles, and that the intact because of the persistence of diaphragbreathing. From the absence of the irritative symptoms commonly met with in hæmorrhage into the meninges it was concluded that the damage was probably limited to the cord itself. The contraction of the pupil and the slow pulse, due, as is well known, to the paralysis of the pupil dilator and cardio-accelerator fibres respectively in their course down the spinal cord to the upper dorsal region, were very noticeable. The exact nature of the injury was dislocation with recoil, the upper four cervical vertebra3 with a part of the fifth having passed forwards on those below them and then sprung back again into their former position, bruising the cord during the process. The situation of the injury in the present case entirely accords with Thorburn’s experience. He states1 that traumatic hsematomyelia usually occurs opposite the fourth, fifth, and sixth cervical vertebrae, and that he has not met with a single case in the dorsal or lumbar regions, a circumstance which he adduces to prove that this form of injury is due to dislocation with recoil, and not to what is vaguely called concussion. Necropsies are very uncommon in this form of hasmatomyelia, as the majority of cases recover. It is to be regretted that this I, patient also sustained a head injury, as otherwise a much ’’i more detailed clinical picture might have been obtained.
fourth matic
was
Reviews The
and
and
Notices of Books. the Cerebral Circulation
Physiology Pathology of Research. HILL,Surgeons M.B.Lond.,of Experimental By LEONARD HunterianProfessor, Professor, Royal Royal College College ofSurgeons -England. Hunterian
: an
of of London : J. and A. Churchill. 1896. Price 12s. THE profound and exhaustive researches upon the cerebral circulation which Dr. Leonard Hill expounded in his Hunterian Lectures for 1896 did much to throw light upon a question that is amongst the most difficult for the physiologist to determine. The re-publication of these lectures in the form here presented will therefore be heartily welcomed, for in them the reader is led step by step towards the explanation of the phenomena of the pathological states of ansemia and compression. The conditions under which the circulation is carried on within the closed cavity of the cranium are not to be explained on anatomical grounds or even deduced from clinical observation. They can only be it is because the experiments and investigated by experiment, carried out for this purpose by the author of this work were
1 Surgery of the Spinal Cord. By William Thorburn.
1889.
skilfully planned and so well adapted to discover the actual conditions that they have been so fruitful. For there is no. question that these physiological researches have led to a. very material change in the point of view from which the phenomena of cerebral anæmia and compression must be regarded. Commencing with the study of the movementsof the brain, cardiac and respiratory, Dr. Hill passes te consider the rôle of the cerebro-spinal fluid, establishing the important fact that in normal states the tension of this fluid is equal to that of the venous pressure. He shows that. the subdural space is physiologically one with the subarachnoid, and that fluid can pass readily from one to the other-a fact which, though anatomically disputed, yet is confirmed by the teachings of pathology. It is instruc. tive to learn that withdrawal of this fluid is at oncefollowed by serous transudation from the blood, and that it is impossible for any increase of the cerebral tension to be transmitted by the cerebro-spinal fluid owing to the tendency to equilibrium between the intra. Dr. Hill also shows that venous and subarachnoid pressure. it is possible to irrigate the brain and spinal cord with ease, his final conclusion to this section being the suggestion "that in such a pathological condition as meningitis irrigation of the meninges might be employed." He addsr ’’ ’’The operation could be as easily and safely carried out as that of irrigation of the peritoneum." The next section deals with the cerebral circulation. Whilst confirming the. general truth of the Monro-Kellie doctrine that the volume of blood in the brain is almost invariably constant, Dr. Hill, by means of most carefully devised experiments, has studied the relations of the intra-cranial circulation. to that of the general circulation. In some respects his results run counter to those of other experimenters, but he gives good reasons for such divergencies,. and affords much matter for thought and inference. One interesting outcome of this research is the evidencethat the circulation within the skull is uncontrolled vaso-motor nerves, but that it is influenced solely by the variations in the general arterial or venous pressure. In so far as this is under any nervous control, it is through the splanchnic nerves that the cerebral circulation is to be. modified, the circulation being accelerated by a rise in arterial pressure and slackened by a fall in that pressure. Owing to the conditions within the skull it is not possible for the intracranial pressure to be more than momentarily raised above that of the cerebral venous pressure. "The cerebral circulation passively follows every change in the general circulation. Every change in the position of an animal from the influence of gravity on the vascular system affects, the cerebral circulation. Every variation in respiration and’ every muscular movement is followed by passive changes in the circulation of the brain. Every heart-beat and every. respiratory undulation is exhibited on the tracings of the cerebral venous or intracranial pressures. Compression of’ the jugulars or the abdomen causes a marked rise in cerebral venous pressure, and muscular movements of the neck by pressure on the jugular veins are sufficient to affect the cerebral circulation. Every stimulus that enters the’ organism and affects the general vaso-motor centre produces a passive effect on the cerebral circulation. Each pleasurable emotion raises the general blood pressure and increases the blood-flow through the brain, and each, painful emotion brings about the opposite result. It is by means of the splanchnic area that the bloodsupply to the brain is controlled"(p. 74). This passage illustrates the prime fact learnt by this researchnamely, the close dependence of the circulation within the skull upon the conditions obtaining in the body generally, and at the same time affords physiological reason for facts of daily experience. A section is devoted to the discussion of the influence of the force of gravity on the so
by