lul. 149, Bureau of Chemistry, U. S. Dept. of Agriculture. 



PLATE III. 



Fig. a. Second crop of plants, grown 5 days in residual solutions (1) distilled water; (2) dis- 

 tilled water + calcium carbonate; (3) sodium nitrate; (4) sodium nitrate + calcium 

 carbonate. 



Fig. b. Second crop, grown 5 days in residual solutions (1) distilled water; (2) distilled water 

 + calcium carbonate; (3) sol. 5, potassium chlorid; (4) sol. 6, potassium chlorid + calcium 

 carbonate; (5) sol. 9, hydrochloric acid; (6) sol. 10, hydrochloric acid + calcium carbonate. 



