Page:The Principles and Practice of Medicine.djvu/24

8 violence; it is not infrequently traceable to syncope or apnoea alone.

Death by may be caused by—1st, want of sufficient stimulus; 2nd, impairment of the muscular fibre of the heart.

1. Want of Stimulus.—Death by Anaemia.—The stimulus to the heart's action is defective when a large quantity of blood is drawn from the vessels, or when it is diminished in quantity, or altered in its properties by exhausting discharges ; or lastly, when imperfectly formed from failing nutrition and the want of proper food. Death under such circumstances may be sudden or gradual, according to the rapidity with which the stimulus is removed. The more prominent phenomena preceding death by Anaemia, are paleness and coldness of the face and of the skin generally, giddiness, nausea, dimness of sight, a feeble and frequent pulse, restlessness, and transient delirium ; and when it is sudden, these symptoms are fol- lowed by sighing respiration and convulsions. The organs after death will be found more or less contracted and blanched, In cases where death is sudden, the cavities of the heart are empty; should it have been gradual, they contain blood, and the walls are flaccid.

2. ''Impairment of the function of the muscular fibre of the Heart.—Death by Asthenia''.—The function of the muscular fibre of the heart may be impaired or suspended by 1st, a sudden shock to the system, producing paralysis of the muscular fibre ; 2nd, by defective nutrition or changes in the fibre itself.

Of a sudden shock to the system, producing paralysis, we have examples in the effect of violent injuries, as a blow upon the head or at the scrobiculus cordis, severe wounds, &c. JVlkny poisons, which cause death soon after they are taken, probably act in the same way. Mental emotion, when fatal, no doubt is so by causing paralysis of the muscular fibre of the heart. In all these instances the nervous system is more or less involved ; but certain poisons, such as that of the upas tree, hydrocyanic acid, &c., act directly upon the muscular fibre, destroying its irritability. Upon examination after death, the cavities of the heart will be found filled with blood; the walls having been unable to contract and expel their contents. But the heart may cease to act from the muscular fibre having become gradually