There may be rigidity of the limbs, or hemiplegia. The pulse is full and bounding, often of high tension with hardened arteries. Albuminuria may be present. Uræmia.--This is less profound than in cerebral hæmorrhage; the patient may be temporarily aroused; the onset is usually gradual. There is albuminuria with casts; albuminuric retinitis may be present. The pupils may be contracted or dilated. The breath has a peculiar so-called “uræmic odour.” The pulse is generally slow, the tension high, and the heart enlarged. The respirations are slow and sighing, and may be Cheyne-Stokes in type. There is no paralysis. There may have been preceding convulsions, and the coma may alternate with these attacks. Anasarca may be present. Diabetic Coma.--This may come on suddenly, and may occur unexpectedly in a person in whom diabetes has not been discovered up to the time of coma. There is sighing respiration, “air hunger.” The odour of acetone in the breath is present, and sugar in the urine. Epilepsy.--Unconsciousness is profound, and comes on immediately with rigidity, followed by convulsions, unilateral, limited to the side of the face, jaws, head and neck or arm, or generalised. Bloody froth exudes from the mouth, the tongue being bitten. The eyes are wide open, the pupils dilated and insensible to light. Micturition may occur. After the convulsive attack has passed off, post-epileptic coma may remain, though usually for a short time only. Syncope.--This has been described under modes of dying (p. 38). In all cases of coma when first seen examine the head for signs of injury, note the odour of the breath, observe the state of the pupils and their reactions, examine the limbs for paralysis, count the pulse and note its character, and the state of the arteries, note the size of the heart and auscultate it at each area. Count and note the character of the respirations, take the temperature, examine the urine, take note of the person‘s age, and inquire into the previous history. SUDDEN DEATH Sudden death may proceed from natural or violent causes. From the former, death may occur unexpectedly and very rapidly, but as a rule the period of time occupied by the phenomena of “dying” is measurable, though inconstant. Should such period of time be immeasurable, death may be considered as instantaneous. Apart from sudden death resulting from violence or poisoning, the common causes are as follows:-- 1. Diseases of the heart: angina pectoris, valvular diseases with failure of compensation, especially aortic regurgitation, degeneration of the heart muscle, rupture of the heart, heart failure from diphtheria or toxic diseases. 2. Diseases of the blood-vessels: rupture of aneurysms or varicose veins, thrombosis, embolism. 3. Cerebral hæmorrhage, especially when in the region of the pons Varolii or cerebellum.