DOSAGE OP VACCINES 



265 



cubic centimetre, and by appropriate dilution any bacterial 

 content of the suspension may be obtained. Thus, if 1,000,000,000 

 organisms per cubic centimetre are desired, 1 c.c. of the suspension 

 must be diluted with 14 c.c. of salt solution. To the prepared 

 dilution of the bacterial suspension 0-5 per cent, of carbolic 

 acid, or 0-2 per cent, of trikresol, is added, and the flask is 

 placed in a water-bath at 56 to 65 C. for one or one and 

 a half hours, according to the resistance of the organism. The 

 proper dilution may subsequently be introduced into small 

 sterile glass ampoules of 1-2 c.c. capacity, which, after sealing 

 and standing for twenty-four hours, may again be sterilised 

 for an hour at 60 C. to ensure the destruction of the organisms ; 

 cultures may be made from the sterilised vaccine to ascertain 

 that this is the case. The lower the temperature and the less the 

 heating, consistent with sterilisation, the more active will be the 

 vaccine. 



The annexed Table gives an idea of the dosage of vaccines, their 

 toxicity, and frequency of inoculation. 



The smaller doses are given at the commencement of the treat- 

 ment, and the doses are gradually increased. 



