INTRODUCTION. 47 



strength to contract ; or by tonic sjjusm, where the organ remains 

 contnicted till death. By gradual cessation of function, it takes 

 place by ancemia ; this is seen after a hemorrhage, where there is 

 insufficient quantity and quality of the blood. 



How does death occur by anaemia ? 



The heart must have blood and the power to keep life in ex- 

 istence ; in anaemia there is not enough blood, and it is of too poor 

 a quality to nourish the tissues. The heart may have the power to 

 contract, but it is empty. 



How does asthenia cause death ? 



This comes from rt, "^without," and stheyios, ''strength." It 

 may take place suddenly when caused by lightning, blows in the 

 abdomen (causing death by paralysis of ganglia). The heart is di- 

 lated and filled with blood, but unable to contract. It takes place 

 slowly, as seen in long lingering diseases, where there is loss of 

 nerve force, as in pleurisy ; or, again, in animals that are starved ; 

 or, if any part of the alimentary tract is occluded by tumors, con- 

 strictions and the like. 



Death beginning at the lungs occurs how? 



The blood remains partly venous by some obstacle of the en- 

 trance of air to the lungs, and occurs when the respiratory muscles 

 fail to act. 



This is improperly called asphyxia, which is, literally, pulse- 

 less ; it is more properly called apncea (suffocation). 



First, when sudden, as from suffocation, or strangulation, or 

 drowning. 



Second, when more slowly, as from pulmonary apoplexy, con- 

 gestion, as when the animal is driven to death, the blood accumu- 

 lates in the vessels of the lungs. AsjyJiyxia means without pulse, 

 while apnma means without breath. 



In what cases is death due to asphyxia ? 



In such cases as drowning, inhaling poisonous gases, as smoke, 

 etc., and also choking. In tetanus, or strychnine poisoning, the 

 chest-walls become immovable ; again, injury to the spinal column 

 high up in the cervical region (pithing). The entrance of air in 

 the pleural cavity, or a great effusion. 



