APPENDIX 



BY THE TRANSLATOR 



A. Vaccination against Asiatic Cholera 



Principle of anti-cholera vaccination. The idea of vac- 

 cination against cholera is not a new one, as it is now some 

 years since Ferran professed to have discovered a cholera 

 vaccine. Other observers were, however, unable to satisfy 

 themselves of the genuineness of his results, and it is only 

 recently that a process established on a scientific basis 

 has been brought forward by M. Haffkine, of the Pasteur 

 Institute. 1 



During an attack of cholera the specific bacillus is only 

 found in the intestinal tract (see p. 144), and experiments 

 show that it dies when injected subcutaneously. The mor- 

 bid process must therefore be due to the absorption of 

 toxines generated by it, and Haffkine's vaccination aims at 

 acclimatising the system by the injection of an 'exalted 

 virus,' much stronger than any which it is likely to en- 

 counter in the ordinary way of infection, so as to enable it 

 to bear such quantities of cholera poison as may be ab- 

 sorbed from the intestine while an attack of the disease is 

 running its course. 



Preparation of the vaccine. The ' exalted virus ' is pre- 

 pared as follows : 2 A suspension, in about 3 c.cm. sterile 

 bouillon, of two or more standard cultures (twenty- four hours' 



1 The experiments (on different lines from Haffkine's) of Klemperei, of 

 Vincenzi, and of Brieger and Wassermann should, however, be also men- 

 tioned. 



2 Wright and Bruce in Brit. Med. Journ. March 4, 1893, p. 227. 



