July 17, 1916 Influence oj Calcium and Magnesium, on Plant Growth 607 



magnesium as was added in the seed. Now, in pots 199 to 202, where 

 a small amount of easily available calcium had been applied, the per- 

 centage in the plants was materially increased. 



Attempts were made to grow wheat and cowpeas in paraffin, so that 

 they would have no access to calcium and magnesium. However, this 

 permitted but little growth, and analyses of the total plants thus grown 

 showed their calcium and magnesium contents to be equivalent to the 



amount present in the seed. 



• 



Table XIII. — Analysis of wheat and soybeans grown in extracted sand — series K 



SOYBEAN PLANT 



WHEAT PLANT 



193 and 194 

 195 and 196 

 197 and 198 

 199 and 200 



201 and 202 



Extracted with hy- 

 drochloric acid 

 in the cold. 



Extracted with hy- 

 drochloric acid 

 on steam bath. 



0.2 gm. sodium bi- 

 carbonate (Na 

 HCO3). 



0.2 gm. sodium bi- 

 carbonate (Na- 

 HCO3) 0.05 gm. 

 calcium nitrate 

 (Ca(N0 3 ) 2 ). 



0.2 gm. sodium bi- 

 carbonate (Na- 

 HCO;,) 0.05 gm. 

 calcium nitrate 

 (Ca(N0 3 ) 2 ) 0.0317 

 gm. magnesium 

 sulphate (MgSOJ 



iS 



n The containers in this series were tall Jena beakers holding 1,350 gm. of sand. 



From Table XIII it can be seen that the plants contained more calcium 

 and magnesium than was added in the seed, thus showing their power 

 to obtain these two elements from sand that had been previously extra 

 with acid. 



