superficial parts, but of a violet, greenish, or yellowish hue. A blow given during life may not appear as an ecchymosis till after death. Contusions in deep-seated parts may give rise to abscess. The change of colour in bruises begins at the circumference, and travels inwards. During the first three days the colour of the bruise is blue, bluish-black, or black; greenish on the fifth or sixth day, and yellow from the seventh to the twelfth. The extent of an ecchymosis depends to a great extent on the looseness of the cellular tissue. A slight contusion causes a slight redness and swelling, and may leave no mark on the dead body unless death has taken place within thirty-six hours. Injuries of this kind sometimes leave a parchment-like hardness and discoloration of the skin. The part looks slightly depressed, due probably to the epidermis having been partly rubbed off, and the skin then drying. Similar marks are sometimes made by blisters. These marks may be produced on the dead body by friction and exposure to the air.

Ecchymosis is to be distinguished from a post-mortem stain-hypostasis-by cutting into the part. In the latter, only a few bloody points are seen; in the former, coagulated blood. In scourging there are parallel ecchymosed lines, or small spots resembling petechiæ. An internal organ may be ruptured, and yet there may be no appearance of injury externally. The liver is most commonly ruptured. The rupture is almost always longitudinal, and in some cases a portion of the gland is more or less detached. The spleen is also not infrequently ruptured; and this occurs most frequently in countries where ague prevails. Rupture of the lungs and brain is rare. When the pelvis is fractured, the bladder is found not infrequently ruptured.

Death in most cases is due to internal hæmorrhage when any of the internal organs are ruptured.

Can the appearance of a bruise be produced after death?

-It appears that all the appearance of a bruise inflicted during life may be produced within two hours after death, and in some rare cases even after the lapse of three hours and a quarter.

The size and form of a bruise should be noted.

Why ?

1. In hanging and strangulation.-The mark due to pressure of the cord on the neck may cause a welldefined ecchymosis.

2. In throttling. The pressure exerted on the throat of the deceased by the fingers of his assailant may leave marks, which may point to the means used to cause death.

In other cases of death by violence.-The impression made by the weapon used may lead to the identification of the murderer. The marks left by the wards of a large door-key once led to the identification of the assailant.

SUFFOCATION.

Death from suffocation is said to result from any impediment to the respiration which does not act by compressing the larynx or trachea.

Death from apnoea may arise from the following

causes

1. Cessation of the action of the muscles of the chest.

2. Arrest of the action of the lungs.

3. Exclusion of atmospheric air from the lungs by foreign bodies lodging in the trachea.

Suffocation may be caused by pressure on the chest, as in persons crushed in a crowd. It may also be due to the respiration of certain gases or the presence of pulverulent substances in the air, which act by choking up the air-passages. Strychnia, by contracting the muscles of the chest, produces death

by suffocation. Abscesses may burst into the trachea, or vomited matters in drunken persons may lodge in the windpipe, and death from suffocation be the result.

Signs of Death by Suffocation. The first effect of arrest to the passage of air into the lungs is the stagnation of blood in the capillaries of the lungs. Nonarterial blood then goes to the brain, and consciousness is soon lost. The respiratory sensation is then arrested by the circulation of venous blood. The left side of the heart becomes emptied, and then weak; the right side full and engorged. The great venous trunks are also more or less full. The arrest of the heart's action is a secondary effect; the right side is paralyzed by being too full, the left by being empty. The heart continues to contract after the lungs have ceased to perform their duty. Death is thus due to apnoea,that is, death beginning at the lungs, and not to syncope. Death in some cases is from neuro-paralysis or nervous apoplexy. In death by shock, which in most cases is instantaneous, both sides of the heart are equally filled. Death the result of disease may present all the signs of death from suffocation, and no suspicion may be aroused as to the cause of death from the post-mortem appearances, especially if putrefaction has set in. The following table is given as an aid to diagnosis in this form of death.

Points to be noticed in forming a Diagnosis of Death by Suffocation.

1. The Blood.-There is unusual fluidity of the blood found in any form of death by suffocation.

This condition is sometimes present in death due to certain diseases,-fevers, etc., and in cases of narcotic poisoning. Even with the blood in this condition, the presence of coagula in the cavities of the heart is not infrequent. The colour of the blood is changed to a dark purple.

2. Animal Heat.-In persons dead from suffocation the animal heat is long retained.

3. Cadaveric Rigidity. Other things being equal, the rigor mortis is as well marked in this kind as in other forms of death.

4. The Lungs.-Hyperæmia of the lungs is rarely absent. In most cases, both lungs are engorged in about equal proportions. Hypostasis-post-mortem stains-must not be mistaken for capillary engorgement.

5. The Heart.-Engorgement of the right side of the heart, the left being empty or nearly so. It is advisable always to examine the heart first, and then the lungs. The pulmonary artery is also much congested.

6. Capillary ecchymoses.-These appear as purplishred spots on the pulmonary pluræ, on the surface of the heart, aorta, and even on the diaphragm. They may appear on the above-mentioned parts in a fœtus suffocated in utero by pressure on the cord. These ecchymoses are rarely seen on adults, most frequently on infants, due probably to the thinness of the coats of the capillaries, which are ruptured in the effort to breathe.

7. Condition and Appearance of the Trachea.-The mucous membrane of the trachea is injected, and appears of a cinnabar-red colour. This is present in every case of death by suffocation, and must not be confounded with the dirty cherry-red or brownish-red coloration due to putrefaction. If suffocation be slowly produced, a quantity of frothy mucus may be found in the windpipe, and also in the smaller tubes of the lungs. Always examine the trachea for foreign bodies, the presence of soot, etc.

8. Kidneys, Vena Cava, etc.-The quantity of blood in the kidneys is always considerable. The abdominal veins are all more or less congested, and the external surface of the intestines present numerous traces of venous congestion.

9. The Brain.-Apoplexy of the brain, as secondary to the pulmonary apoplexy, may be more or less present, attended with its well-known appearances.

10. Face, Tongue, and Mouth. The expression of the face is not characteristic of death by suffocation, and differs in no particular from that common to other forms of death, being more frequently pale than turgid, and starting of the eyes is not often seen. The tongue may or may not be protruded beyond the teeth. The presence of froth about the mouth is not constant, but is of common occurrence in those dying from natural

causes.

Was the suffocation homicidal, suicidal, or accidental? -Suffocation may occur accidentally during the act of swallowing, and by foreign bodies placed carelessly in the mouth and then forced suddenly into the windpipe. Examine the lips for the presence of ecchymosis and other marks of violence. In France, a favourite mode of committing suicide by suffocation is the use of irrespirable gases-carbonic acid, carbonic oxide, and the like. Collateral circumstances must be taken into consideration, and will more or less help to point to the true cause of death.

HANGING, STRANGLING, AND THROTTLING.

Hanging.-Death by hanging is caused by the more or less perfect suspension of a body by a cord applied round the neck, the weight of the body acting as the constricting force.

Strangling.-Death due to pressure made on the neck by any form of ligature carried circularly round the neck. The cord in hanging is placed more obliquely than in strangulation.

Throttling.-Death due to the constant pressure of the fingers on the throat.

The cause and nature of the death in all of the