SERUM AND VACCINE. 503 



poison of South African snakes that 30 c.c. are needed for the 

 rapid recovery of even a mild case of snake bite, while a serious 

 case requires the injection of 60 c.c. and often more. This is 

 alarming, for the reason that if a dose of 30 c.c. are injected at 

 one dose without any preliminary treatment, into a person who 

 is hypersensitive to serum owing to having been previously 

 injected for snake bite, or for the cure of some disease, it will 

 possibly kill him. 



The urgent need for a serum prepared from the venoms of 

 the various poisonous snakes of this country is, therefore, 

 apparent. Ten c.c. of this serum is equal to at least 30 c.c. of 

 any of the foreign sera. 



A dose of 10 c.c. of this speciahzed serum brought Mr. James 

 Williams, and two assistants at the Museum, out of the shadow 

 of death. If Williams, who was hypersensitive to serum, had 

 received a dose of 30 c.c. of the foreign serum which is being 

 sold freely in South Africa, the serum sickness which supervened 

 would have killed him without the shadow of a doubt. If 

 foreign sera of weak antidotal strength against the venoms of 

 South African snakes is largely used here there will be more 

 deaths caused by it from anaphylaxis, or serum sickness, than 

 cures of snake venom poisoning.* 



Serum and Vaccine. 



Serum is usually confused with vaccine, both being thought 

 by many people to be one and the same substance. Serum is a 

 product from the blood of horses. Vaccine is a culture made 

 from microbes. Colonies of these are bred and afterwards killed. 

 After many careful and skilful processes have been gone through, 

 the dead microbes or germs, with their toxins or excretions, are 

 graded into doses. When finally sterilized and prepared, the 

 product is termed vaccine. 



Vaccines are now used for the purpose of reinforcing our 

 bodily resistance against disease, and also for the actual treat- 

 ment of disease conditions. The injection of the vaccine culture 

 causes the body to manufacture a potent substance which blends 



* Anaphylaxis is the shock which sometimes follows the injection of a 

 dose of horse serum into a person who has had an injection at some 

 previous time. It occurs at once or within 24 hours. Serum sickness or 

 serum poisoning, on the contrary, may develop, as in Williams' case, two 

 or three days after the injection. 



