740 INFECTION AND IMMUNITY. 



tericidal power of glycerin has been overestimated, 

 and that while it kills pyogenic cocci within two 

 weeks when at the body temperature, such organ- 

 isms may live for months in glycerin when in the 

 ice chest; and, of course, our glycerinated virus 

 is kept in the ice chest. Tetanus spores live for 

 months in glycerin and glycerin has practically 

 no neutralizing action on tetanus toxin. Glycerin 

 does have the power, however, of attenuating the 

 tetanus spores, and its slow bactericidal action is 

 well established. As stated above, the vaccine 

 should be glycerinized for some weeks before it is 

 put on the market. Glycerin has the added ad- 

 vantage for the manufacturer of enabling him to 

 dilute his lymph moderately (from 50 to 60 per 

 cent.) without impairing the virus. 



Of much more importance for the safety of 

 virus than glycerinization are proper hygiene and 

 cleanliness during the whole process of prepara- 

 tion. The powers recently conferred on the Sur- 

 geon-General by an act of Congress have resulted 

 in a great improvement in the purity of the vac- 

 cine now on the market. 1 



While it can not be expected that vaccine will 

 be entirely free from bacteria, it is possible to re- 

 duce their number to a low minimum and to elim- 

 inate pathogenic forms, particularly pathogenic 

 cocci, tetanus and tubercle bacilli. 



vaccination. The technic of vaccination is so well known 

 that no description is needed. It need only be 

 stated that in scarifying it is undesirable to 

 cause hemorrhage and that the operation is a sur- 

 gical procedure, demanding surgical cleanliness 



1. John F. Anderson "Federal Control of Vaccine Virus." 

 Jour, of the Amer. Med. Assn., June 10. 1905. 



