CONTENTS. 



Page. 



Introduction 5 



Experiments with nutrient solutions and distilled water cultures 6 



Description of solutions and method of sowing 6 



First crop of seedlings 6 



Second crop of seedlings 12 



Comparison of the first and second crops 13 



Experiments using aluminum and ferric hydroxids to reduce acidity of 



solution 15 



Experiments using clover and timothy with wheat 16 



Conclusions. . 17 



ILLUSTRATIONS. 



Page. 

 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. Fig. &. First crop 

 of plants, grown 9 days in (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 8 



II. Fig. a. First crop of plants, grown 9 days in (1) distilled 

 water; (2) distilled water+calcium carbonate; (3) sol. 7, 

 potassium sulphate; (4) sol. 8, potassium sulphate-f calcium 

 carbonate; (5) sol. 11, sulphuric acid; (6) sol. 12, sulphuric 

 acid+calcium carbonate. Fig. 6. First crop of plants, grown 

 9 days in (1) distilled water; (2) sol. 3, sodium nitrate; 



(3) sol. 7j potassium sulphate; (4) sol. 13, sodium nitrate+po- 

 tassium sulphate 8 



III. Fig. a. Second crop of plants, grown 5 days in residual solu- 

 tions (1) distilled water; (2) distilled water+calcium car- 

 bonate; (3) sodium nitrate; (4) sodium nitrate+calcium car- 

 bonate. Fig. 6. Second crop grown 5 days in residual solu- 

 tions (1) distilled water; (2) distilled water+calcium car- 

 bonate; (3) sol. 5, potassium chlorid; (4) sol. 6, potassium 

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



(6) sol. 10, hydrochloric acid+calcium carbonate 12 



3 



