PLATE I. 



EXPLANATION. (See p. 212.) 



Water-ciiltxires of Japanese Buckwheat, supplied with the ingre- 

 dients of a Normal Solution, viz. : Sulphates, Nitrates, Phosphates and 

 Clilorides of Potassium, Magnesium, Calcium and Iron, except as stated 

 below. 



I and la. Solution normal. Potassium as Chloride. 



II. Solution without Potassium. 



II3. "Without Potassium for 4 weeks, thereafter Potassium Chloride. 



III. Potassium as Nitrate. Chlorine as in Normal. 



IV. Potassium as Sulphate. Chlorine one-fourth of Normal. 



V. Potassium as Phosphate. Chlorine one-flfth of Normal. 



VI. Sodium hut not Potassium. 



VIII. Lithium. 



IX. Without Calcium. 



X. Without Chlorine. 



XI. Without Nitrogen. 



The meter-scale (39| inches) serves to measure the dimensions of the 

 plants. 



