ASPHYXIA 119 lion being called into play. The blood pressure rises and the pulse becomes rapid. In the second stage the expiratory muscles of respiration become more active with spasmodic movements, which are followed by convulsions of nearly all the muscles of the body. Owing to venous and capillary stagna- tion the face and hands are deeply congested and cyanosed. Consciousness . becomes confused and the sphincters are relaxed. In the third stage the respiratory centre is paralysed. The muscles become flaccid, there is complete insensibility, the reflexes are lost, and the pupils are widely dilated. The blood pressure falls. Prolonged sighing inspirations occur at longer and longer intervals until they cease altogether, and death ensues. The pulse is scarcely perceptible, but the heart may continue to beat for some minutes after respirations have quite ceased. The three stages last for about five minutes before death takes place. They may be prolonged for two or three times as long. Occasionally asphyxia may bring about death almost instantly. Post-mortem Appearances—External.—The face is either calm and pale in slow asphyxia, or distorted, congested and blue in cases of sudden asphyxia. The lips and nails are livid. Cadaveric lividity is more marked. The tongue is protruded in most cases; and frothy and bloody mucus comes from the mouth and nostrils. Rigor mortis i£ usually slow to commence, but may be rapid in some cases. Internal.—The mucous membrane of the trachea and larynx is cinnabar red due to its injection and contains froth. Tj^e lungs are dark and purple in. colour and gorged with dark venous blood; on being cut they exude frothy, dark fluid blood. The air-cells are distended or even ruptured due to emphysema. The right cavity of the heart is full containing dark-coloured, imperfectly clotted blood, and so are the pulmonary artery and the venae cavse. Tl^£ left cavity,"the aorta and the pulmonary veins are empty. In many cases, both, sides of the heart are found to be full, if examined soon after destth but, after rigor mortis has set in, the heart is found contracted and empty, or the tension in the abdomen presses on the inferior vena cava, and drives blood up into the heart. Similarly, the lungs are found heavier with blood collected in the dependent parts if examined sometime after death, or the tension in the abdomen or contraction of the heart muscle will drive more blood into the lungs, irrespective of the cause of death. The brain is congested but not so much as in death from coma. The abdominal organs are found congested. Numerous small petechial haemor- rhages or ecchymoses known as Tardieu's spots, are seen under the serous membranes of various organs due to rupture of the capillaries caused by intra-muscular pressure. These are usually round, dark and well-defined, varying in size from a pin's head to a small lentil. They are found under the pleurse, pericardium, thymus, meninges of the braul and cord, conjunc- tive, and even under the skin of the face and neck. They are sometimes seen in deaths occurring from scurvy or purpura. Gordon's Classification of Death.—Gordonl has suggested a classification of medico-legal deaths which is based upon the concept that the cessation of the vital functions depends upon tissue anoxia, which is brought about in the following four different ways : — I. Defective oxygenation of the blood in the lungs—anoxic anoxia, which is produced (a) by obstruction to the passage of air into the respi- ratory tract as in suffocation, smothering and overlaying ; (b) by obstruc- tion to the passage of air down the respiratory tract as in drowning, choking from impaction of a foreign body, throttling, strangulation and hanging; (c) 1. Brit. Meet. Jour., Sep. 9, 1944, p. 337.