PLATE I. 



EXPLANATION". (See p. 212.) 



"Water-cultures of Japanese Buck"wheat, siipplled "with the ingre- 

 dients of a Normal Solution, viz. ; Sulpliates, Nitrates, Phospl"iates 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-fifth of Normal. 

 VI. Sodium but not Potassium. 



Vm. Lithium. 



IX. "Without Calcium. 



X. "Without Chlorine. 



XI. "Without Nitrogen. 



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

 plants. 



