188 



INDEX 



Widal reaction, nature of, 71 

 Wool-sorters' disease, 174 

 Wright's investigations on op- 

 sonins, 72 



YEAST, definition of, 13 

 in fermenting milk, 137 



Yellow fever, quarantine in, 61 



transmission of, 57 



virus of, 125, 128 

 Yoghurt, bacteriology of, 138 



ZINGHER, diphtheria immunity, 



98 

 Zoolak, bacteriology of, 138 



