"habu" venom and its serum therapy. 155 



suceptibility of the animal to the snake venom varies greatly in individ- 

 uals, which makes the experiment more difficult than with the diphtheria 

 toxin. 



The differences in susceptibility of different species of animals to this 

 poison is not so marked as it is to tetanus or diphtheria toxin. 



The following table shows this, mice being taken as the standard: 



Table 3. 



1 fatal close per gram of mouse = 



12 fatal doses per gram of guinea pig. 

 10 fatal doses per gram of rabbit. 

 10 fatal doses per gram of pigeon. 

 5 fatal doses per gram of chicken. 



1 fatal doses per gram of dog. 



2 fatal doses per gram of rat. 

 s fatal dose per gram of cat. 



i fatal dose per gram of frog. 



It is evident from the above that the guinea pig and rabbit have the 

 highest susceptibility, while frogs and cats have the lowest. 



EXPERIMENTAL. 



Mice. — The animals received 0.001 cubic centimeter of venom subcutaneously. 

 The individuals appear ill after five minutes, with erection of the hair; slow, 

 irregular respiration with inspirator}' effort; paralysis of extremities causing 

 difficult walking; a tumor is produced at the site of the injection, presenting a 

 dark purple color. The tips of the ears, nose and claws become cyanotic; respira- 

 tion at length becomes fainter and fainter, the pulse diminishes and is stopped 

 in about forty-five minutes, when death takes place. Convulsions seldom appear. 



Post-mortem examinations show a subcutaneous oedema with clots about the 

 site of the injections. The liver, spleen and lungs are anaemic, their size being 

 normal. If the dose used was sublethal, the animal gradually recovers from the 

 affection, while the oedematous areas become necrotic and finally a spontaneous 

 cure is effected at this site. 



Guinea pigs. — The animals die in two hours after receiving 0.01 cubic centimeter 

 subcutaneously; symptoms appear in fifteen minutes, swelling is evident at the 

 site of the injection, it turns to a dark, purple color, spreading gradually; 

 the abdomen becomes distended; the animal can not arise to its feet after being 

 turned on its back; respiration becomes slow; the tips of the ears appear pale; 

 shivering sets in, accompanied by a slight opisthotonus. Death takes place after 

 paralysis has developed. 



Post-mortem examination shows a subcutaneous oedema with haemorrhage. The 

 internal organs are anaemic without any other changes. The bowel contents are 

 fluid. 



Rabbits. — The animals die in five hours after receiving 0.03 cubic centimeter 

 subcutaneously, practically with the same symptoms as are observed in other 

 animals. A well-developed oedema at the site of injection makes its appearance, 

 accompanied by haemorrhage. The animal becomes so lethargic that it walks with 

 difficulty and finally can not stand on its feet. An excessive dose, say of 0.04 cubic 

 centimeter, when given intravenously, will kill a rabbit in three to ten minutes. 

 The animal thus treated appears as if in severe pain, and dies after a period of 



