Nomenclature. The word Gun, in the surgical term Gunshot Injuries,' has not the limited signification to which it is restricted in military phraseology, but includes fire-arms of all descriptions. It is synonymous with the French 'arme-à-feu,' as the term 'Gunshot Injuries' is with blessures par armes-à-feu.' The French were for a long time more precise than ourselves in their divisions of the blessures,' or hurts, into contusions par armes-à-feu,' contusions by fire-arms, and plaies d'armes-à-feu,' open wounds by fire-arms; the English expression 'gunshot wounds' having been commonly employed both for simple contusions as well as for open wounds. A proper distinction between the general term 'injury,' and the specific terms 'contusion' and 'wound,' was made in the authorised nomenclature of diseases' of 1868, and there is no likelihood of the terms being employed otherwise than according to their strict signification in future.

As by far the largest number of wounds resulting from fire-arms in warfare are caused by bullets from portable fire-arms, muskets and rifles, and as these are the wounds which have most engaged the attention of military surgeons, it might have been supposed that these weapons would have furnished the general name for the class of injuries under consideration. The surgical phrase Gun-shot injury, however, owes its origin to large guns (mortars and cannon) having been the first kinds of offensive weapons depending upon the action of gunpowder which were used in warfare, and also to the fact of the first portable fire-arms having been called 'hand-guns,' from their being almost identical in shape and construction with the guns of larger size. Nearly two centuries elapsed after the employment of guns before muskets were introduced, and nearly three centuries before they were established as regular instruments of warfare. Although in time they came to be the most frequent sources of wounds in military operations, English surgical writers, when describing fire-arm injuries, still continued to make use of the phrase which had originally been adopted shortly after the employment of guns and gunshot, and long familiarity with it still makes it the most convenient to employ.

General nature of gunshot injuries, and the principal features which distinguish them from other injuries having affinity with them.-Regarded as a group of bodily lesions, gunshot injuries comprehend every kind and degree of hurt which is capable of being produced on the human frame by the mechanical impulse of obtuse bodies: non-penetrating contusions, from the merest bruise of the surface, to others where, although the superficial structures remain unbroken, deeply seated organs are pounded into pulp; and penetrating wounds, from the slightest division of the skin, to wounds causing instantaneous death by total destruction of the organism.

The whole group naturally finds its place within the general

class of Contused Injuries.' The first set, indeed, non-penetrating gunshot injuries or contusions, differ in no respects from the contusions produced by blows of equal severity from other blunt instruments. When a fragment of shell, a spent bullet, or other projectile of low velocity, impinges upon part of the surface of the body, the condition of the structures which are injured by the missile is precisely similar to what it would be if the same part had been struck by any other obtuse body, of like size and weight, armed with the same amount of force. It is only, however, in rare and exceptional instances that open contused wounds inflicted by other instruments than those which are propelled by great explosive force, present the features characteristic of gunshot wounds.2 Such instances do occur. The trunk or limb of a person brought into collision with part of a railway carriage moving at express' speed is destroyed in the same way as it would be if struck by a massive projectile; and men and animals are recorded to have been killed on certain occasions in tropical countries by large hailstones striking them with the accumulated momentum resulting from the force of gravitation, just as if they had been shot by a missile discharged from a fire-arm. Ordinary contused wounds, however, being for the most part produced by agents moving at relatively low rates of speed, are wounds complicated with over-stretching of the divided parts and adjoining structures; if very severe, are accompanied with more or less textural lacerations and ruptures extending far beyond the open wound itself, perhaps with complete disintegration of some of the structures concerned; but they are rarely, if ever, attended with that complete attrition and displacement, and even total removal of substance, which are so constantly characteristic of wounds produced by gunshot. A wound inflicted by a rifle bullet at high speed, through some of the softer tissues of the body, leaves an open empty track through which the projectile has passed; the walls of the track, or a portion of them, are devitalised by the action of the projectile; disintegrated pulp and dead shreds of tissue, which have been broken up and forced aside by the bullet in its passage, are jammed into these walls; while scarcely any bruising of the surrounding structures beyond is rendered visible, or indeed is produced. The same bullet may so glance along the surface of the head as to leave an open furrow from which the hair, scalp, pericranium, and a portion of bone will have disappeared, they having been carried away and dispersed by the bullet in its flight. The larger and heavier the rifle-bullet, the more obvious are these effects. A fragment of shell, at high speed, coming into collision with the soft parts of a limb, leaves a gap just as if the structures detached from the wounded surface had been scooped out by some cutting, though blunt, instrument. Portions of tendons, nerves, and ligaments, which, as a rule,

escape destruction in the most severe contused wounds produced by ordinary blunt instruments, are liable to be completely destroyed and removed by the action of projectiles. It is this complete attrition, separation, and dispersion of parts of natural tissues opposed to projectiles, together with the existence of certain complications and special features with which gunshot wounds are generally combined, as will be noticed hereafter, that particularly distinguish them from ordinary divisions of parts accompanied with a certain amount of structural bruising or crushing, and that, further, justify their usual separation into a distinct group, almost as much as the peculiarities of the projectiles to which they generally owe their origin, or the special circumstances under which they are presented to surgeons in military practice.

CHAPTER II

AGENTS CONCERNED IN THE PRODUCTION OF GUNSHOT INJURIES

Preliminary remarks. It was stated in the preceding chapter, when giving a definition of gunshot injuries, that these hurts are usually produced by (1) an explosive compound confined and fired in a special way, in order to provide the necessary force; (2) a weapon, or closed case, usually contrived so as to give the required direction to this force, and also to the projectile upon which the force is intended to act; and (3) a body which, being propelled by the force thus generated, becomes the missile upon. which the bodily injury directly depends.

In order to study gunshot injuries systematically, it is necessary to consider within certain restricted limits each of the agents which combine in producing them. The first two, however, viz., the explosive compounds and the fire-arms or other instruments employed for causing the wounds, need only brief remarks in this work. The projectiles to which the injuries are directly attributable are the agents of greatest interest to surgeons, and they must be described and illustrated at greater length. The guns and weapons from which they are discharged can be most conveniently noticed at the same time as the projectiles themselves. The explosive compounds will be treated of in the present chapter.

On the Explosive Compounds employed with Fire-arms, Hollow Projectiles, and other Military Contrivances.

The explosive compounds chiefly in use.--Various explosive compounds have been employed for propelling projectiles from fire-arms, for bursting shells, for exploding fougasses and mines,

and for other military purposes. The chief of these are gunpowder, fulminates, and certain chemical compounds. The many serviceable qualities of gunpowder have caused it to be the explosive agent constantly employed in past wars with fire-arms. Fulminating powder has only been used for a few special purposes. Of modern fire-arm explosives, there are a very large number of varieties; a few of the more important among them only will be noticed in the present chapter.

Gunpowder.-Depending, as gunshot projectiles in a large proportion still do, on the impelling force of gunpowder for their velocity, and consequently for their destructive energy, it will be well to consider briefly what the nature of this force is. So many injuries occur from the action of gunpowder itself when exploded, such as concussions, contusions, lacerated wounds, and burns, and instances of particles of unexploded gunpowder accidentally lodging in parts of the body are so frequent, that its composition and some of its chemical properties may also be briefly called to mind with advantage.

Without referring to its discovery, or its application to military purposes, both of which seem to be involved in great obscurity, it may be noticed as a curious fact that certainly for five hundred years it has been composed of the same mixture of ingredients as at present, viz., nitrate of potash, or saltpetre, charcoal, and sulphur, though not always in the same proportions, nor manufactured in the same manner. In the composition mentioned, the charcoal supplies the fuel, the saltpetre provides the oxygen for its ignition, while the combustible sulphur causes the ignition to take place more speedily, and renders the combustion more complete. The gunpowder used with early fire-arms was very irregular in its effects, and comparatively weak, from being made of impure ingredients, and from being used in the form of a fine powder, such as is now known as meal powder.' Some time elapsed before it was made in the form of coarse grains. Its strength was greatly increased by this change, owing to the opportunity it afforded for the free passage of flame among the particles, and to the ignition in consequence not being limited merely to the surface of the charge of powder, as it had previously been. Other changes have since been made in the manufacture of gunpowder, all tending to increase its force, and to make this force more manageable under the circumstances to which it has to be applied in warfare.

The proportions of the ingredients of the gunpowder made in England have very constantly been, of nitre 75 parts, sulphur 10, and of charcoal 15 parts; but in some gunpowder of recent manufacture the proportions of the nitre and carbon have been increased to 79 parts of the former, and 18 of the latter, while the sulphur has been reduced to 3 parts. This has been called

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brown gunpowder,' to distinguish it from the old black gunpowder.' Improvements have been made in the manufacture of gunpowder, so that perfect sameness of quality has been obtained, and uniformity of effects secured when like quantities are fired. Various forms, dimensions, weights, and degrees of density have been given to the separate grains,' in order to adapt their modes of ignition and rates of combustion to guns and fire-arms of different sorts and sizes, and thus to fit the agent to the work that has to be done by it with scientific accuracy. It would be out of place in a work of this kind to attempt to describe the steps which have been taken to attain these results; but it is important for surgeons to know that they can accept as a fact that equal rates of velocity are impressed on projectiles by equal charges of the same kind of powder.

The chemical qualities of the several ingredients of which gunpowder is composed are too well known to need mention. Their innocuous character when brought into contact with the tissues of the human frame was fully established as early as the time of Ambrose Paré, who demonstrated that gunpowder had no hurtful effects when swallowed, and was unable to impress any noxious qualities on projectiles such as to influence the wounds caused by them. Daily proofs are afforded, if any were wanting, of the local inertness of gunpowder by its employment in tattooing, and its lodgment with impunity in scattered grains in the skin and subcutaneous tissues of persons exposed to accidental explosions, in which some particles of the gunpowder are generally projected unfired.

Gunpowder explodes at a temperature of about 700° Fahr. When free, in open air, it burns rapidly away, or deflagrates, with much smoke, but little noise; when confined, it explodes with a loud report and much force. The force of the explosion, resulting from the production of gases expanded by the intense heat developed by the chemical action between the combustible ingredients and the nitre, varies according to the conditions under which the gunpowder is fired. Variations in the density of gunpowder, and also in the shape and size of the several grains. cause its explosive force to be developed in greater or less time as required. The fact that the gases resulting from the explosion can be made to expand more or less gradually, so as to continue their impulsive action on the shot while it passes along the gun, specially distinguishes gunpowder from fulminates, and from all highly sensitive explosives. The total amount of gas resulting from the explosion occupies about 250 times the volume of the original powder. A certain amount of water exists, combined with the nitre and charcoal, and the conversion of this ingredient into steam-superheated steam - increases the gaseous volume. The temperature of the flame produced by the combustion has