GROUP OF PYOGENIC COCCI. 53 



and mouth with antiseptic solutions. Children living 

 in the samei house should not be permitted to attend 

 school until it is certain that they have not been 

 infected. 



Cerebrospinal meningitis in the epidemic form 

 has been attended with a very high mortality in the 

 past, especially among young children. In some epi- 

 demics it has been as high as 90 per cent. The treat- 

 ment with antimeningitis serum, however, has been 

 attended with success, and the excessive mortality has 

 been considerably reduced by its use. In this country 

 this method of treatment was begun by Dr. Flexner 

 and Dr. Jobling at the Rockefeller Institute in New 

 York. The serum, is made by injecting horses with 

 slowly increasing doses of meningococci that have 

 been killed by heat. The tolerance of the animals to 

 the poison of the meningococci is gradually increased 

 in this way until they are able to withstand many 

 times the fatal dose. This tolerance depends upon an 

 active immunity due to the formation within their 

 bodies of protective substances that neutralize the 

 poison. After eight or twelve months the horses are 

 bled and the blood-serum containing the protective 

 substances is used for treating patients sick with 

 meningitis. 



The extended trial of the serum in a number of 

 epidemics has shown that, the earlier it is used after 

 the onset of the infection, the greater its curative 

 value. For this reason it is customary to' inject the 

 serum immediately after the withdrawal of the cere- 



