The cause and nature of the death in all of its forms just mentioned are in general the same. Pressure on the trachea--thus arresting respiration--and also on the important vessels and nerves of the neck, results in death, which may be brought about in four different ways: 1. Cerebral congestion, or apoplexy. 2. Congestion of the lungs and heart--apnœa or asphyxia. 3. Combination of above--apoplexy and asphyxia or apnœa. 4. Neuro-paralysis--nervous apoplexy, or syncope. The following table will show the relative frequency of each form of death: Remer. Casper. Apoplexy 9 9 Asphyxia 6 14 Mixed 68 62 -- -- 83 85 -- -- =Traumatic asphyxia= occurs when a heavy weight such as a fall of earth or masonry compresses the chest, and thoracic respiration is impossible. The head and neck appear ecchymosed, the purplish-blue lividity generally ending abruptly at the lower part of the neck or upper part of the thorax, about the level of the clavicles. The conjunctivæ are ecchymosed, and there may be epistaxis. This discoloration does not disappear on pressure by the finger, indicating its petechial character. If the person survive long enough, the discoloration gradually disappears, passing through the colour changes of an ordinary ecchymosis. The effects on the eyes may be such as to be followed by changes in the retina, and optic atrophy leading to loss of vision. Parts of the neck pressed upon by clothing may escape ecchymosis, and present a white mark of almost normal skin. HANGING Death by hanging is caused by the more or less perfect suspension of the body by a cord applied around the neck, the weight of the body acting as the constricting force. The body need not hang completely, partial suspension is sufficient to cause death. The ligature surrounds the neck above the thyroid cartilage, the epiglottis is pushed against the back of the pharynx, the base of the tongue and the soft parts are pressed into the cavity of the pharynx, so that the obliteration of the naso-pharyngeal and the laryngeal passages is complete. Death is due to asphyxia and pressure on the cervical blood-vessels, even if the air-passages be not completely occluded; stoppage of the cerebral circulation being sufficient to cause death; in such a case the signs of asphyxia are absent. Consciousness is quickly lost, due to pressure on the vessels, and, for this reason, in accidental or suicidal hanging the person is prevented from making any effort to save himself.