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



PLATE I. 



Fig. a. First crop of plants, grown 9 days in (1) distilled water; (2) distilled water + calcium 

 carbonate; (3) sodium nitrate; (4) sodium nitrate + calcium carbonate. 



'g.b First crop of plants grown 9 days in (1) distilled water; (2) distilled water + calcium 

 carbonate; (3) sol 5, potassium chlor.d; (4) sol. 6, potassium chlorid + calcium car- 

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



