104 Report S.A.A. Advancement of Science. 



Whether the horse can be as safely passed through this modified 

 phase of the disease in the warm weather, whether a further inocula- 

 tion of a stronger or less attenuated virus will be necesary to ensure 

 resistance, how long the immunity acquired from the mild attack will 

 last, and whether it will be necessary to adjust a vaccine to different 

 localties, are all questions besides many others which future obser- 

 vation must decide. 



My resources in time, help, and material, have in the past been 

 straightened, but now more adequate facilities are at command, and 

 I hope future progress will be commensurate with broadening 

 opportunities. I have intentionally refrained from referring to details 

 of technique, and with my reasons for reticence in this respect, I believe 

 you will not be found to disagree. Much more extended observation 

 is necessary to prove its practical usefulness, and to bring to light 

 and correct its drawbacks. Our monetary loss in Natal during the 

 past season has been at least ;£i 2,000, and _;^5o,ooo is a small 

 estimate of the loss to South Africa, but apart from economic con- 

 siderations — the mass of animal suffering reflected in such figures, 

 is sufficient to render the hope of devising some alleviation for the 

 same an ambition for any man. 



We can safely say that the successful man will owe as much to th«i 

 efforts of others as to his own endeavours, for investigations of this 

 sort are progressive and one worker builds on the foundation of 

 his predecessor. 



