Dec. IS, 1914 



Assimilation of Colloidal Iron by Rice 



207 



Table II. — Growth of rice with dialyzed iron and ferric chlorid — Experiment J I 



In this experiment, where equivalent and small quantities of iron 

 were used, the dialyzed-iron preparation appeared to have an availa- 

 bility of about three-tenths that of the ferric chlorid. 



Experiment III. — A third series was conducted, using equivalent 

 small quantities of iron, ten times this amount of iron from dialyzed iron, 

 and twice this quantity of iron from ferric chlorid. The results are 

 given in Table III. 



Table III. — Growth of rice uith dialyzed iron and ferric chlorid — Experiment III 



Flasks Nos. 26 to 30 did not agree well with Nos. 21 to 25, so it is 

 possible that the average of 1.30 gm. is too low. It is apparent from 

 the preceding tests that the dialyzed iron was much less available than 

 the ferric chlorid. On the basis of the Fe content, the dialyzed iron had 

 to be present in at least five times the amount of ferric chlorid to produce 

 the same yield. 



The percentages of iron in the dry substance of the tops was deter- 

 mined in the plants from Experiment III. The percentages varied from 



