Aids To Forensic Medicine And Toxicology Part 3

XI.--CONTUSED WOUNDS AND INJURIES UNACCOMPANIED BY SOLUTION OF CONTINUITY

If a blow be inflicted with a blunt instrument, there is produced a bruise, or _ecchymosis_, of which it is unnecessary here to describe the appearance and progress. A bruise may be distinguished from a post-mortem stain by the cuticle in the former often being abraded and raised. When an incision is made into the bruise, the whole of the subcutaneous tissues are found to be infiltrated with blood-clot, and there is no clear margin. In the case of a post-mortem stain the edges are sharply defined, not raised, and, on section, mere b.l.o.o.d.y points are seen which are the cut ends of the divided blood vessels.

XII.--INCISED WOUNDS AND THOSE ACCOMPANIED BY SOLUTION OF CONTINUITY

These comprise incised, punctured, and lacerated wounds. In a recent incised wound inflicted during life there is copious haemorrhage, the cellular tissue is filled with blood, the edges of the wound gape and are everted, and the cavity of the wound is filled with coagula.

Lacerated wounds combine the characters of incised and contused wounds.

They are caused by falls, being ridden over, machinery crushes, bites, blows from blunt weapons, etc. The wounds heal by suppuration.

_Punctured wounds_ come intermediate between incised and lacerated. They are greater in depth than in length, being caused by sword or rapier thrusts. They cause little haemorrhage externally, but death may be due to internal haemorrhage. They may be complicated by (1) the introduction of septic material adhering to the instrument; (2) the entrance of foreign bodies which lodge in the wound, not only carrying in septic matter, but acting as mechanical irritants; (3) injury to deeper parts, which may at the time be difficult to detect.

An apparently _incised wound_ may be produced by a hard, blunt weapon over a bone--_e.g._, shin or cranium. It is often difficult to distinguish between a wound of the scalp inflicted with a knife and one made by a blow with a stick. A puncture with a sharp-edged, pointed knife leaves a fusiform or spindle-shaped wound. A wound from a blow with a stick might be of this character, or it might present a jagged, swollen appearance at the margin, with much contusion of the surrounding tissues. If the wound is seen soon after it is inflicted, examination with a lens may disclose irregularities of the margins, or little bridges of connective tissue or vessels running across the wound, and so be inconsistent with its production by a cutting instrument.

_Lacerated wounds_ as a rule bleed less freely than those which are incised. Symptoms of concussion would favour the theory of the injury having been inflicted by a heavy instrument. Again, it is often difficult to decide whether the injury which caused death was the result of a blow or a fall. A heavy blow with a stick may at once cause fatal effusion of blood, but this might equally result from fracture of the skull resulting from a fall. The wound should be carefully examined for foreign bodies, such as grit, dirt, or sand. The distinction between incised wounds inflicted during life and after death is found in the fact that a wound inflicted during life presents the appearances already described, whereas in a post-mortem incised wound only a small quant.i.ty of liquid venous blood is effused; the edges are close, yielding, inelastic; the blood is not effused into the cellular tissue, and there are no signs of vital reaction. The presence of inflammatory reaction or pus shows that the wound must have been inflicted some time before death, probably two or three days.

_Self-inflicted wounds_ are made by the person himself in order to divert suspicion, or in order to bring accusation against another. Such wounds are always in front, not over vital organs, and superficial in character. Note the condition of the clothes in such cases.

XIII.--GUNSHOT WOUNDS

These may be punctured, contused, or lacerated. Round b.a.l.l.s make a larger opening than those which are conical. Small shot fired at a short distance make one large ragged opening; while at distances greater than 3 feet the shot scatter and there is no central opening. The Lee-Metford bullet is more destructive than the Mauser. The former is the larger, but the difference in size is not great. The Martini-Henry bullet weighs 480 grains, the Lee-Metford 215, and the Mauser 173. Speaking generally, a gunshot wound, unlike a punctured wound, becomes larger as it increases in depth; the aperture of entrance is round, clean, with inverted edges, and that of exit larger, less regular than that of entrance, and with everted edges.

In the case of high-velocity bullets from smooth-bore rifles, including the Mauser and Lee-Metford, the aperture of entry is small; the aperture of exit is slightly larger, and tends to be more slit-like. There is but little tendency to carry in portions of clothing or septic material, and the wound heals by first intention, if reasonable precautions be taken.

The external cicatrices finally look very similar to those produced by bad acne pustules.

The contents of all gunshot wounds should be preserved, as they may be useful in evidence. A pocket revolver, as a rule, leaves the bullet in the body.

Wounds inflicted by firearms may be due to accident, homicide, or suicide. Blackening of the wound, singeing of the hair, scorching of the skin and clothing, show that the weapon was fired at close quarters, whilst blackening of the hand points to suicide. Even when the weapon is fired quite close there may be no blackening of the skin, and the hand is not always blackened in cases of suicide. Smokeless powder does not blacken the skin. Wounds on the back of the body are not usually self-inflicted, but a suicide may elect to blow off the back of his head. A wound in the back may be met with in a sportsman who indulges in the careless habit of dragging a loaded gun after him. If a revolver is found tightly grasped in the hand it is probably a case of suicide, whilst if it lies lightly in the hand it may be suicide or homicide. If no weapon is found near the body, it is not conclusive proof that it is not suicide, for it may have been thrown into a river or pond, or to some distance and picked up by a pa.s.ser-by.

A bullet penetrating the skull even from a distance of 3,000 yards may act as an explosive, scattering the contents in all directions; but the bullet from a revolver will usually be found in the cranium.

The prognosis depends partly on the extent of the injury and the parts involved, but there is also risk from secondary haemorrhage, and from such complications as pleurisy, pericarditis, and peritonitis. Death may result from shock, haemorrhage, injury to brain or important nervous structures.

XIV.--WOUNDS OF VARIOUS PARTS OF THE BODY

1. =Of the Head.=--Wounds of the scalp are likely to be followed by (1) erysipelatous inflammation; (2) inflammation of the tendinous structures, with or without suppuration. A severe blow on the vertex may cause fracture of the base of the skull. Injuries of the brain include concussion, compression, wounds, contusion, and inflammation. Concussion is a common effect of blows or violent shocks, and the symptoms follow immediately on the accident, death sometimes taking place without reaction. Compression may be caused by depressed bone or effused blood (rupture of middle meningeal artery) and serum. The symptoms may come on suddenly or gradually. Wounds of the brain present very great difficulties, and vary greatly in their effect, very slight wounds producing severe symptoms, and _vice versa_. A person may receive an injury to the head, recover from the first effects, and then die with all the symptoms of compression from internal haemorrhage. This is due to the fact that the primary syncope arrests the haemorrhage, which returns during the subsequent reaction, or on the occurrence of any excitement.

Inflammation of the meninges or brain may follow injuries, not only to the brain itself, but to the scalp and adjacent parts, as the orbit and ear. Inflammation does not usually come on at once, but after variable periods.

2. =Injuries to the Spinal Cord= may be due to concussion, compression (fracture-dislocation), or wounds. That the wound has penetrated the meninges is shown by the escape of cerebro-spinal fluid. The cord and nerves may be injured (1) by the puncture; (2) by extravasation of blood and the formation of a clot; and (3) by subsequent septic inflammation.

Division or complete compression of the cord at or above the level of the fourth cervical vertebra is immediately fatal (as happens in judicial hanging). When the injury is below the fourth, the diaphragm continues forcibly in action, but the lungs are imperfectly expanded, and life will not be maintained for more than a day or two. When the injury is in the dorsal region, there is paralysis of the legs and of the sphincters of the bladder and r.e.c.t.u.m, but power is retained in the arms and the upper intercostal muscles act, the extent of paralysis depending on the level of the lesion. In injuries to the lumbar region the legs may be partly paralysed, and the rectal and bladder sphincters may be involved.

_Railway spine_, or traumatic neurasthenia, may be set up by concussion of the cord as a result of blows or falls. Pa.s.sengers after railway accidents, or miners, often suffer from this affection.

3. =Of the Face.=--These produce great disfigurement and inconvenience, and there is a risk of injury to the brain. The seventh nerve may be involved, giving rise to facial paralysis. Punctured wounds of the orbit are especially dangerous. Wounds apparently confined to the external parts often conceal deep-seated mischief.

4. =Of the Eye.=--The iris may be injured by sharp blows, as from the cork of a soda-water bottle. It is usually followed by haemorrhage into the anterior chamber, and there may be separation of the iris from its ciliary border. Wounds at the edge of the cornea are often followed by prolapse of the iris. Acute traumatic iritis or irido-cyc.l.i.tis may supervene four or five days after the injury. The lens is frequently wounded in addition to the cornea and iris. In dislocation of the lens into the anterior chamber as the result of a blow, the lens appears like a large drop of oil lying at the back of the cornea, the margin exhibiting a brilliant yellow reflex. Partial dislocations of the lens as the result of severe blows generally terminate in cataract.

5. =Of the Throat.=--Very frequently inflicted by suicides. Division of the carotid artery is fatal, and of the internal jugular vein very dangerous on account of entrance of air. Wounds of the larynx and trachea are not necessarily or immediately dangerous, but septic pneumonia is very apt to follow. Wounds of the throat inflicted by suicides are commonly situated at the upper part, involving the hyoid bone and the thyroid and cricoid cartilages. The larynx is opened, but the large vessels often escape. In most suicidal wounds of the throat the direction is from left to right, the incision being slightly inclined from above downwards. At the termination of a suicidal cut-throat the skin is the last structure divided, the wound being shallower as it reaches its termination; the wounds often show parallelism. The weapon is often firmly grasped in the hand. Inquiry should be made as to whether the patient is right or left handed, or ambidextrous.

Homicidal cut throat is usually very severe and situated low down in the neck or far to the side.

6. =Of the Chest.=--Incised wounds of the walls are not of necessity dangerous; but severe blows, by causing fracture of the bones and internal injuries, are often fatal. The symptoms of penetrating wounds of the chest are--(1) The pa.s.sage of blood and air through the wound; (2) haemoptysis; (3) pneumothorax; and (4) protrusion of the lung forming a tumour covered with pleura. Fracture of the ribs may be due to direct violence, as from a blow, when the ends are driven inwards, or to indirect violence, as from a squeeze in a crowd, when the ends are driven outwards.

7. =Of the Lungs.=--These usually cause haemorrhage, and are frequently followed by pleurisy, either dry or with effusion, and by pneumonia.

8. =Of the Heart.=--Penetrating wounds are fatal from haemorrhage, of the base more speedily than of the apex; but life may be prolonged for some time even after a severe wound to the heart. Injury to the right ventricle is the most fatal injury and the most frequent. Rupture from disease usually occurs in the left ventricle; rupture from a crush is usually towards the base and on the right side.

9. =Of the Aorta and Pulmonary Artery.=--Fatal.

10. =Of the Diaphragm.=--Generally fatal, owing to the severe injury of the other abdominal organs. If the diaphragm be ruptured, hernia of the organs may result.

11. =Of the Abdomen.=--Of the walls, may be dangerous from division of the epigastric artery; ventral hernia may follow, internal haemorrhage, etc. Blows on the abdomen are p.r.o.ne to cause death from cardiac inhibition.

12. =Of the Liver.=--May divide the large vessels. Venous blood flows profusely from a punctured wound of the liver. Wounds of the gall-bladder cause effusion of bile and peritoneal inflammation.

Laceration of the liver may result from external violence without leaving any outward sign of the injury; it is commonly fatal. There is rapid and acute anaemia from the pouring out of blood into the abdominal cavity. This may also occur with injuries of other organs in the abdomen.

13. =Of the Spleen.=--Fatal haemorrhage may result from penetrating wounds or from rupture due to kicks, blows, crushes, especially if the spleen be enlarged.

14. =Of the Stomach.=--May be fatal from shock, from haemorrhage, from extravasation of contents, or from inflammation. The danger is materially lessened by prompt surgical intervention.

15. =Of the Intestines.=--May be fatal in the same way as those of the stomach. More dangerous in the small than in the large intestines.

16. =Of the Kidneys.=--May prove fatal from haemorrhage, extravasation of urine, or inflammation.

17. =Of the Bladder.=--Dangerous from extravasation of urine. In fracture of the pelvis the bladder is often injured, and extraperitoneal infiltration of urine occurs, with frequently a fatal issue.

18. =Of Genital Organs.=--Incised wounds of p.e.n.i.s may produce fatal haemorrhage. Removal of t.e.s.t.i.c.l.es may prove fatal from shock to nervous system. Wounds of the spermatic cord may be dangerous from haemorrhage.

Wounds to the v.u.l.v.a are dangerous, owing to haemorrhage from the large plexus of veins without valves.

XV.--DETECTION OF BLOOD-STAINS, ETC.