In reply to the two first questions, I shall quote the words of the late Professor Casper: Consequently the scars occasioned by actual loss of substance, or by a wound healed by granulation, never disappear, and are always to be seen upon the body. But the scars of leech bites, or lancet wounds, or of cupping instruments, may disappear after a lapse of time that cannot be more distinctly specified, and may therefore cease to be visible upon the body. It is extremely difficult or impossible to give any certain or positive opinion as to the age of a scar.' My own experience bears out the above statement; for I have a patient who informs me that she was repeatedly bled in both arms, yet I can only detect, after the most careful examination, the marks in one arm, and these are by no means very distinct.

With regard to the last question, the subject of the disappearance of tattoo marks has given rise to considerable discussion in the great Tichborne case recently tried at Bar. On this subject the experiments of Hutin, Tardieu, and Casper appear to point to the fact that tattoo marks may become perfectly effaced during life,' but that after death the colouring matter with which the marks were made may be found in the lymphatic glands. Hutin found that, in 506 men who had been formerly tattooed, the marks had disappeared from 47 of the number. On this subject see also Tardieu's paper in the Annales de Hygiène publique (Jan. 1855, p. 171 et seq.).

As a means of disguise the hair may be dyed, or the colour may be changed from dark to light.

There is one more question bearing on this subject,

viz :

What amount of light is necessary for the purpose of identification?

In one well-authenticated case, a lady was enabled to identify the person of a thief by the light emitted by a momentary flash of lightning; and it also appears probable that the flash of light from a gun or pistol

may be of sufficient intensity for the purposes of identification.

EXAMINATION OF PERSONS FOUND DEAD.

The Object of such Examination.

1. To answer the question, Who is it?

As an aid to diagnosis, it is important to remember that certain trades leave marks by which those engaged in them may be identified. Thus, in shoemakers there may be more or less depression of the lower portion of sternum, due to the constant pressure of the last against the bone.

In coachmen, corns may be formed between the thumb and index finger, and between the index and the second finger of the left hand, from the pressure of the reins.

In stonemasons, from the constant action of picking up the bricks, flattening of the tip of the thumb and index finger of left hand is not uncommon.

The finger-ends of turners and coppersmiths are also more or less flattened; in the latter a deposit of the metal may take place.

2. In the case of an infant found dead, it may be necessary to determine whether it was born alive, and also whether it had reached that period when it could maintain an existence apart from its mother.

3. To determine the time which may have elapsed since death.

4. To ascertain the cause or causes of death.

Modes of Sudden Death.

Syncope. Asphyxia.

Coma.

SYNCOPE, from συγκοπτω, I strike down. Arrest of

the action of the heart.

This condition may be brought about by

1. Deficiency of blood due to hemorrhage.
2. Effect of certain diseases and poisons.

Post-mortem Signs.—The cavities of the heart contain a normal quantity of blood. The blood is simply arrested in its course; blood is therefore found in the large veins and in the arteries. The brain and the lungs are not engorged with blood.

ASPHYXIA, from å priv. et σpuģis, pulse. Apnoea is the better term-å priv. et πvew, I respire. Asphyxia, or death from defect in the quality of the blood, is brought about when any impediment is placed on the healthy action of the lungs.

Causes.-1. Certain diseases affecting the lungspneumonia, bronchitis, etc. etc.

2. Mechanical obstruction to respiration-strangulation, drowning, hanging, etc.

Post-mortem Signs.-Engorgement of the pulmonary artery, the right cavities of the heart, and venæ cavæ, is present; but on the left side of the heart, the cavities, together with the aorta, are either empty or contain but little blood. It must be remembered, however, that cases of asphyxia do sometimes occur where the cavities on each side of the heart are empty, or nearly So. If also the obstruction to respiration be imperfect, the circulation may be continued for some time, congestion of one or more of the internal organs being the result.

COMA.-Death in this case is due to some cerebral

mischief.

Cause.-Apoplexy, fracture of the cranial bones, compression or destruction of the brain substance.

Post-mortem Signs.-Congestion of the membranes and substance of the brain, and of the lungs. The cavities of the heart, especially those of the right, contain more or less blood.

Real or Apparent Death.

It will be unnecessary here to discuss any of the

theories put forth with regard to cases of apparent death or prolonged trance, but simply to note in the order of their occurrence the phenomena which attend real death.

Real Death.

1. Entire cessation of respiration and circulation; no murmur heard on auscultation.

2. The lustre of the eye is lost immediately after death. 3. The most powerful stimulus applied to the body does not cause any reaction. The muscles may, however, be made to contract shortly after death by the stimulus of a slight blow, or by galvanism.

4. The surface of the body becomes of an ashywhite colour.

Exceptions.

a. Persons of florid complexions retain this for some time after death.

b. The red or livid edges of ulcers.

c. Blue, black, or red tattoo marks, if not effaced during life, do not disappear.

Ecchymoses retain the hue they had at the time of death.

d. An icteric' coloration existing at death never becomes white. Death from jaundice.

e. A rosy tint of the skin described by Devergie on those poisoned by carbonic acid.

5. The temperature of the body at the time of death is retained for some time. Cooling will depend on the medium in which the body is placed.

Average internal temperature of body during life, 98° to 100° F.

a. Fat persons retain the heat longer than lean ones; adults longer than children or old persons.

Bodies cool by

1. Radiation.
2. Conduction.
3. Convection.

b. Bodies immersed in water cool more rapidly than in air.

This fact may be of importance in determining survivorship in a case of drowning.

c. Bodies in bed and covered by the clothes, or in cesspools and in dung-heaps, cool less rapidly than when exposed.

d. Persons killed by lightning keep longer warm than others (?).

e. Death by suffocation retards the process of cooling. f. The body may be cold externally, but possess a considerable amount of heat when the internal organs are exposed. Persons who have died of cholera, yellow fever, or suddenly of some acute disease— rheumatism· may retain for some hours a considerable amount of heat. It has even been asserted, that in some diseases -cholera-there is an increase of temperature soon after death.

g. Most bodies under ordinary circumstances are, as a rule, quite cold in from eight to twelve hours after death.

6. Relaxation more or less general of the muscular system takes place.

If the above signs are alone present, death must have taken place in from ten to twelve hours at the longest (Casper).

7. Want of elasticity in the eyeball.

This condition invariably occurs in from twelve to eighteen hours after death.

8. Flattening of the muscles of those parts on which the body rests, due probably to loss of vital turgidity. 9. Hypostases, due to the gravitation of the blood to the most dependent parts of the body. They begin to form in from eight to twelve hours, and increase in size till putrefaction sets in.

10. Cadaveric rigidity.

Cadaveric rigidity, or rigor mortis, in every case