Over extensive fractures of this nature general oedema and infiltration of the scalp, due to extravasation of blood, were present.

When the exit was situated in the frontal region ecchymosis often extended to the eyelids and down the face, while in the occipital region similar ecchymosis was often seen at the back of the neck.

The opening in the dura mater at the aperture of entry was either slitlike, or more often irregular from laceration by the fragments of bone driven in by the bullet. At the point of exit a similar limited opening corresponded with the spot at which the bullet had pa.s.sed, while separate rents of larger size were often seen at some little distance.

The latter were the result of laceration of the outer surface of the membrane by the margins of the large loose fragments of bone above described.

Injury to the brain more than corresponded in extent to the fractures of the bone. Pulping of its tissue existed over a wide area both at the points of entrance and of exit. In the former position the amount of damage was the less, the gross changes roughly corresponding with the tissue directly implicated by the bullet itself, and the fragments of bone carried forward by it. The degree of splintering of the skull therefore in great part determined the severity of the lesion. At the exit aperture much more widespread destruction existed, while ma.s.ses of brain tissue, small shreds of the membranes, fragments of bone, and _debris_ from the scalp were found occasionally bound together by coagulated blood and protruding from an exit opening of some size. The largest ma.s.ses of such _debris_ were most often seen in instances in which the bullet had entered by the base to escape at the vertex of the skull.

The brain in the line of injury suffered comparatively slightly, but small parenchymatous haemorrhages into its tissue indicated in lesser degree the same type of injury undergone by the ma.s.s of brain pulp and small blood-clots found at the external limits of the wound. Beyond this extensive haemorrhages at the base of the skull were common.

With regard to the extensive character of the brain destruction in the region of the aperture of exit, it must be borne in mind that this lesion corresponds in position with one which would exist even if the injury were of a non-penetrating degree. A large proportion of the contusion and destruction is therefore explained by violent impact of the projected brain with the skull prior to the pa.s.sage of the bullet, and not to the direct action of the bullet on the tissues.

These cases of 'general injury' afford a marked example of the lesions to which the term 'explosive' has been applied, and as such have an important bearing on the theories held as to the mode of production of explosive effect. The increased area of tissue damage at the aperture of exit favours the theory of direct transmission of a part of the force with which the bullet is endowed, to the molecules of tissue bounding the track made by the projectile. Thus the area of destruction corresponds with the cone-like figure which one would expect to be built up by the vibrations spreading from the primary point of impact. The exit region of the skull is subjected not alone to the force of the travelling bullet, but also to that exerted over a much wider area by the tissue to which secondary vibrations have been communicated. The brain itself is, in fact, dashed with such violence against the bone as to cause a great part of the injury.

No doubt the brain in its reaction to the bullet forms as near an approach to a fluid as any solid tissue in the human body, and experimental observation has shown how greatly its presence or absence in the skull affects the degree of comminution on the exit side; hence the fondness for the so-called hydraulic theory that has been always exhibited in the case of these injuries. The localisation of the injury in its highest degree to the neighbourhood of the exit aperture, however, shows that in any case the main wave takes a definite direction in a course corresponding to that of the bullet.

The real importance of the presence of the brain within the skull in increasing the amount of damage at the exit end of the track, is as a medium for the ready transmission of forcible vibrations. That the latter are to some extent conveyed as by a fluid is evidenced by the occasional presence of brain matter and fragments of bone in the aperture of entry, which suggests recoil or splash such as would be expected from a fluid wave.

Experience of the character of the lesions observed after severe concussion by the ordinarily somewhat coa.r.s.er forms of violence common to civil life, fully explains the severity of the damage to the brain tissue met with in injuries due to bullets of small calibre. Viewing the elaborate arrangements which exist for the preservation of the central nervous system from the moderate vibration incidental to ordinary existence, it is easy to appreciate the harmfulness of such exquisite vibratory force as that transmitted by a bullet of small calibre travelling at a high rate of velocity.

_Effect of ricochet in the production of severe forms of injury._--In connection with the lesions above described mention must be made of cases in which the aperture of entry reaches a large size, or a portion of the skull is actually blown away.

Examples of the former cla.s.s were not uncommon; I will briefly relate one.

(48) A Highlander while lying in the p.r.o.ne position at Rooipoort, was struck by a bullet probably at a distance of about 1,000 yards. A large entry wound in the scalp was produced, while the defect in the skull was coa.r.s.ely comminuted and was capable of admitting three fingers into a ma.s.s of pulped brain. Both brain matter and fragments of bone were found in the external wound, which was situated just anterior to the right parietal eminence. The bullet pa.s.sed onwards through the base of the skull, crossing the external auditory meatus, fracturing the zygoma and probably the condyle of the mandible, and eventually lodged beneath the ma.s.seter muscle.

Blood and brain matter escaped from the external auditory meatus.

The patient was brought off the field in a semi-conscious condition, the pupils moderately contracted but equal, the pulse 66, very small and irregular in beat, the respiration quiet and easy, and with paralysis of the left side of the body. The faeces had been pa.s.sed involuntarily.

The wound was cleansed and bone fragments removed. The patient had to travel in a wagon for the next three days until the column halted. The progress of the case was unsatisfactory, as the wound became infected, and the man eventually died on the 14th day of general septicaemia, but with little evidence of local extension of septic inflammation.

In this instance the head was no doubt struck by a bullet which had previously made ricochet contact with the ground. I saw several such cases.

Closely connected with such injuries are those in which large portions of the skull and scalp were actually blown away. I never witnessed one of these myself, but I recall two instances described to me by officers who lay near the wounded men on the field. In one the frontal region was carried away so extensively that, to repeat the familiar description given by the officer, 'he could see down into the man's stomach through his head.' In a second case the greater part of the occipital region was blown away in a similar manner, and this was of especial interest as the wounded man was seen to sit up on the b.u.t.tocks and turn rapidly round three or four times before falling apparently dead. The observation offers interesting evidence of the result of an extensive gross lesion of the cerebellum.

In the absence of exact information, it may well be that such injuries as the two latter were produced by some special form of bullet, but as both were produced while the patients were lying on the ground, and therefore especially liable to blows from ricochet bullets, I am inclined to attribute both to this cause.

In considering injuries of the above nature, one cannot help speculating on the possible influence of a head-over-heels ricochet turn on the part of the bullet while traversing the long sagittal axis of the skull. It is not uncommon for apical target ricochets to present evidence of damage to the apex and base of the mantle alone. This must depend on a rapid turn on impact, which might well be imitated in the case of the skull, and would then go far to explain the production of some of the most severe forms of explosive exit wounds met with. See cases 48, 54, 68.

Short of ricochet, the influence of simple wobbling must also be considered in shots from a long range. The entry wound may be large as a result of this condition, but as the velocity possessed by the bullet is low, the injuries would probably not be of a very severe nature.

In connection with the subject of wobbling, reference should be made to the form suggested by Nimier and Laval, in which the wobble, as the result of resistance to the apex of the revolving bullet, a.s.sumes the form of movement seen when the spin of a top is failing. This would explain a peculiarity in some wounds of entry over the skull first pointed out to me by Mr. J. J. Day. When such wounds were explored, as well as the presence of brain in the entry aperture, a number of fragments of the external table of the skull were found everted and fixed in the tissues of the scalp. As already suggested, this may be mere evidence of splash, but it may be equally well explained by a process of wobble around the axis of revolution of the bullet. This might, no doubt, also be invoked to explain the displacement of some of the fragments in fractures of the long bones, where considerable resistance to the pa.s.sage of the bullet is offered.

II. _Vertical or coronal wounds in the frontal region._--These injuries were common, and offered some of the most interesting ill.u.s.trations of the variations in symptoms and effects following apparently exactly identical lesions, judging from the condition of the external soft parts alone; since the latter sometimes gave little indication of the force (dependent on the rate of velocity) which had been applied.

With the lower degrees of velocity simple punctured fractures of the skull resulted, without extensive lesion of the frontal lobes as evidenced by immediate symptoms. The nature of the fractures differed in no way from the punctured fractures we are familiar with in civil practice. The openings of entry in the bone were irregularly rounded, corresponding in size to the particular calibre of the bullet concerned.

The margin consisted of outer table alone, while the inner table was either considerably comminuted, or a large piece was depressed, wounding the dura-mater and projecting into the brain substance (see fig. 63).

The aperture of exit presented exactly the opposite characters, the splintering comminution or separation of a large fragment affecting the outer table, while the inner presented a simple perforation. The latter condition is represented in figs. 71 and 72, and I will here give short notes of four ill.u.s.trative cases, as being the shortest and most satisfactory method of conveying a correct idea of the nature of such injuries.

[Ill.u.s.tration: FIG. 62--Aperture of Entry in Frontal Bone. Case No. 50.

1/2]

(49) _Vertical perforation of frontal bone._--Wounded at Belmont, while in the p.r.o.ne position. Aperture of _entry_ (Mauser), at the anterior margin of the hairy scalp on the left side; course, through the anterior part of the left frontal lobe, roof of the left orbit, cutting the optic nerve and injuring the back of the eyeball, floor of the orbit, the antrum, the hard palate, and tongue. _Exit_, in mid line of the submaxillary region. No cerebral symptoms were noted, and on the fifth day the man was sent to the Base hospital without operation; the pulse was then 70 and the temperature normal.

The movements of the eyeball were perfect, but blindness was absolute. At the Base hospital the eye suppurated and was removed. The patient was then sent home apparently well. He has since been discharged from the service, and is now employed as a painter in Portsmouth Dockyard.

(50) _Vertical perforation of frontal bone._--Wounded at Paardeberg while in the p.r.o.ne position. Range, 600-700 yards.

Aperture of _entry_ (Mauser), at the fore margin of the hairy scalp above the centre of the right eyebrow; course, through the anterior third of the right frontal lobe, roof of orbit, front of eyeball, margin of floor of orbit making a distinct palpable notch, and cheek; _exit_ through the red margin of the upper lip, 1/2 an inch from the right angle of mouth. The bullet slightly grooved the lower lip.

The patient rose almost immediately after being struck, and walked about a mile, although feeling dizzy and tired. The wounds, which both bled considerably, were then dressed. After three days' stay in a Field hospital, the patient was sent in a bullock wagon three days and nights' journey to Modder River and thence to the Base.

There was anaesthesia over the area supplied by the outer branch of the supra-orbital nerve, extending from the supra-orbital notch backwards into the parietal region, but none over the area supplied by the second division of the fifth nerve.

On the tenth day there were no signs of cerebral disturbance except a pulse of 48. The eyeball was suppurating, and the temperature rose to 99 at night. The lids were still swollen and closed.

A few days later the eyeball was removed and at the same time a flap was raised and the fracture explored (Major Burton, R.A.M.C.). An opening somewhat angular, 1/3 of an inch in diameter, was found with a thin margin in the outer table of the skull (fig. 62); when this was enlarged with a Hoffman's forceps, an opening in the dura was discovered, and cerebro-spinal fluid escaped. A piece of the inner table of the skull (fig. 63), 3/4 by 1/3 an inch in size, was discovered projecting downwards vertically into the brain. This latter was removed and the wound closed. Healing by primary union followed, and no further symptoms were observed.

[Ill.u.s.tration: FIG. 63.--Fragment of Inner Table depending vertically from lower margin of puncture shown in fig. 62. The centre was perforated. Exact size]

(51) _Transverse frontal wound._--Wounded at Paardeberg. The man was sitting down at the time he was struck, in the belief that he was out of the range of fire. The _entry_ and _exit_ wounds were almost symmetrical, placed on the two sides of the forehead at the margin of the hairy scalp, 2-1/4 inches above the level of the external angular processes of the frontal bone. The patient lost consciousness for about half an hour, then rose and walked half a mile to the Field hospital. The wounds were dressed, and after a stay of three days in hospital, the man was sent the three days' journey to Modder River; during the journey he got in and out of the wagon when he wished. After two days' stay at Modder, a journey was again made by rail to De Aar (122-1/2 miles). The wounds were healed.

The man stayed at De Aar nearly a month, and then, rejoining his regiment, made a two days' march of some 22 miles on hot days. He had to fall out twice on the way by reason of headache, feeling dizzy, and 'things looking black.' He did not own to any loss of memory or intellectual trouble, but was invalided to England. This patient returned to South Africa later, and is now on active service.

(52) _Transverse frontal wound._--Within a few days an almost identical symmetrical wound in the frontal region occurred in the same district, from a near range. The patient became immediately unconscious, and remained so until his death some four days later, his symptoms being in no way alleviated by operation and the removal of a quant.i.ty of bone fragments and cerebral _debris_. At the _post-mortem_ examination, extensive destruction of both hemispheres of the brain was revealed, and large fissures extended into the base of the skull.

III. _Glancing or oblique perforating wounds of varying depth in any portion of the cranium._--These injuries were the most common, the most highly characteristic of small-calibre bullet wounds, the most interesting from the point of view of diagnosis, prognosis, and treatment, and beyond this they formed the variety most unlike any that we meet with in civil practice.

They were met with in every region of the cranium, and in every degree of depth and severity. The lesser are best designated as gutter fractures, the deeper are perforating and gradually approximate themselves to the type of injury described as cla.s.s 1.

When the bullet struck a prominent or angular spot on the skull a considerable oval-shaped fragment was occasionally carried away, leaving an exposed surface of the diploe (case 60, p. 274). Under these circ.u.mstances the apparent lesion on raising a flap was slight, but exploration often showed extensive intra-cranial mischief. Thus in the case referred to both dura and brain were wounded, and continuing haemorrhage led to the development of progressive paralysis, relieved only by operation.

From the more deeply pa.s.sing bullets a more or less oval opening resulted, in which both tables were freely comminuted and displaced.

These cases differed from the typical gutter fracture only in length and outline, and the nature of the accompanying intra-cranial lesion was identical, while in the latter particular they differed much from fractures in which the impact of the bullet was direct, in spite of a near resemblance in the appearances in the osseous defect.

I saw one instance in which a circular fissure about 1-1/2 inch from the actual opening of entry surrounded the latter, the area of bone within the circle being somewhat depressed, though radial fissures were absent.

In several of these cases fragments of lead were either found on the fractured surface of the bone or within the cranial cavity, showing that the bullets had undergone fissuring of the mantle, or had actually broken up on impact.

_Gutter fractures._--The nature of the injury to the bones in these is best ill.u.s.trated by a series of diagrams of sections such as are shown below.

[Ill.u.s.tration: FIG. 64.--Gutter Fracture of first degree. The drawing does not show well the small fragments of bone usually carried from the margins of the depression by the bullet.]

In the most superficial injuries the outer table was grooved and depressed, usually with loss of substance from small fragments directly shot away: these latter had either been driven through the wound in the soft parts, or remained embedded on the deep aspect of the enveloping scalp (fig. 64). In the less common variety the scalp was slit to a length corresponding with the injury to the bone, but more often oval openings in the skin existed at either end of the track. The inner table was practically never intact, but the amount of comminution naturally varied with the depth to which the outer table was implicated (fig. 65 _A_, and _B_).

The following is an ill.u.s.trative example of this degree, and also emphasises the consequences which may follow primary non-interference.

[Ill.u.s.tration: FIG. 65.--Diagrammatic transverse sections of varying condition of bones in Gutter Fractures of the first degree. _A._ With no loss of substance. _B._ With comminution.]

(53) _Superficial gutter fracture in parietal region.

Convulsive twitchings. Secondary paralysis._--Wounded at Modder River. Range, 400 yards. A scalp wound 3 inches in length ran vertically downwards, commencing 1 inch from the median line, and situated immediately over the upper third of the right fissure of Rolando. The patient was unconscious for several hours after the injury, and later suffered with severe headache, and twitchings in the left shoulder and arm.

The wound healed, but a well-marked groove was palpable in the bone beneath, and the twitchings persisted. The latter came on about every twenty minutes, and loss of power in the left upper extremity, and to a less degree in the lower, developed. The memory was defective, and the patient suffered at times with headache. The pupils were equal but sluggish in action. No changes were discovered in the fundus beyond a well-developed myopic crescent at the lower and outer part of the left disc (Mr. Hanwell).