Transformation, etc., of Pathogenic Microbes. 97 



vaccinates the rabbit against tuberculosis ; this pre-' 

 servative action is more intense with the serum of a 

 tuberculized dog and manifests itself even when the 

 injection is made seven dajs after the virulent inocu- 

 lation. 



We must mention here, in connection with pre- 

 ventives of a chemical nature, the attempts at vac- 

 cination against rabies with the essence of tansy, 

 against tetanus with strychnine, and against tubercu- 

 losis with tannin. 



4. Preventive inoculation ivith the virus of another 

 disease. — Cow-pox is preservative against variola; we 

 place the example in this paragraph although, ac- 

 cording to recent researches, it should have its place 

 along with the inoculations of attenuated virus. Re- 

 cent experiments of M. Eternod have, in fact, demon- 

 strated the identity of variola with vaccinia. It 

 should be said, however, that these results have been 

 contested. 



The attenuated microbe of fowl cholera vaccinates 

 ^fowls against charbon and against Davaine's septi- 

 caemia; guinea pigs vaccinated against symptomatic 

 charbon are also vaccinated against the septic vibrio, 

 but the reverse does iiot hold good. 



IV. Destruction and annihilation of pathogenic germs. 



The destruction of pathogenic germs is a very im- 

 portant point to consider. The hygienist and the 

 physician should apply themselves to the suppression 

 of dangerous germs wherever they exist, that is, 

 upon the patient and upon the objects which have 

 been contaminated in his surroundings; this opera- 

 9 



