GERMICIDES AND ANTISEPTICS. 213 



of the pathogenic test-organism, give rise to the 

 mistaken assumption that this had been destroyed 

 by the action of the germicide agent to which it 

 had been subjected. 



Vaccine virus has also been used by the writer, 

 and by other experimenters, to test the compara- 

 tive value of disinfectants. The method consists 

 in dividing a certain quantity of virus from the 

 same source into two parts, and subjecting one 

 portion to the action of the agent to be tested, 

 while the other is reserved to prove the reliability 

 of the material used. A negative result from vac- 

 cination with the disinfected virus, and a positive 

 result from that not disinfected, is evidence of the 

 power of the disinfectant used to destroy the in- 

 fective virulence of the material. The experiment 

 must of course be made upon unvaccinated chil- 

 dren, and it is best to make it in duplicate, two 

 punctures being made upon one arm with the 

 disinfected virus, and two in the other with that 

 not disinfected. 



A complete resume of the experiments which 

 have been made to determine the value of anti- 

 septics and disinfectants would require more space 

 than can be given to this subject in the present 

 volume. Nor can the results obtained by different 

 methods be brought together in tabular form ; for 

 discrepancies exist, due to various circumstances, 

 and an extended discussion would be required to 

 reconcile these, or to determine which were en- 

 titled to the greatest consideration. These dis- 



