SUBJECT INDEX 



393 



Vitamines, 20. 

 Volcanic dust, 29. 

 Volcanic gases, 46. 

 Volmetiol, 204. 



Warburg's method, 245. 

 Water. r61e of, 153, 309. 

 Willstatter's theory, 282. 

 W inkler's method, 242. 

 Wurmser's theory, 288. 



Xanthophyll, 145, 344, 366, 368. 



amount in leaves, 369, 372, 373. 



physical properties, 353. 

 1-Xylose, 191, 192. 



Yeast. 



reducing action of, 51. 

 Yellow leaves, 150. 



Zinc sulfate, 172. 



