The Wohurn Pot- Culture Ea-perlments, 1910-11-12. 331 



character to that used in 191(1, and made up with similar 

 additions of magnesia. 



The harvest results were : — 



These results are most significant, showing as they do, 

 unmistakably, that the grain once affected by the action of 

 magnesia, if again subjected to it in a second year shows a 

 marked decline of crop, the more marked the more be the 

 magnesia present. In other words, the grain has become 

 subject to the toxic influence of magnesia used in excess. It 

 will be noted that the untreated produce is not widely different 

 in the two years 1910 and 1911, so that the falling off in 1911 

 cannot be put down to season. It will be observed also how 

 the nitrogen percentage rises in the grain with the increase of 

 magnesia. 



Having now shown how the wheat crop could be influenced 

 by the magnesia treatment, it was determined to try in 1912 

 whether by planting again the seed obtained in 1911, in soil 

 of normal character, its cropping power could be restored, or 

 if once affected it would remain so. Accordingly the seed of 

 " 8 B " as grown in 1911 was resown in November, 1911 in the 

 same sort of soil as had been used in 1911 for the " no 

 treatment" set. There was nothing particular noticed as 

 regards the germination, and the general appearance of the 

 plants was good throughout, they being strong and healthy 

 and showing good tillering. The results obtained at harvest 

 were : — 



