192 F. B. GUTHRIE AND R. HELMS. 



grain was sown on June 3rd, was a mixture of about one 

 part of a light sand, one part of clay, and two parts of loam. 

 Each pot received in addition the following fertilising 

 mixture : — 15 grms. sulphate of ammonia ; 6 grms. super- 

 phosphate; 4 grms. sulphate of potash; together with 

 varying quantities of the substances whose action was under 

 investigation. 



The composition of this soil was as follows : — 



Moisture 3*83 



Organic matter ... 13*75 

 Nitrogen '208 



Soluble in strong HCl. 



Lime *165 per cent. 



Potash -065 „ 



Phosphoric acid ... '107 „ 



Magnesia *072 „ 



The soil was found to contain in addition '016 per cent, 

 sodium chloride, so that the percentages of common salt 

 in the pots devoted to experiments to test the action of 

 this substance must be increased by this amount. On this 

 account the pots that were resown on subsequent dates 

 were filled with soil No. 2 which was one in which 

 potatoes had been growing. 



The composition of soil No. 2 was as follows : — 



Moisture 2*91 



Organic matter ... 8*33 

 Nitrogen "070 



Soluble in strong HCl. 



Lime '440 



Potash -077 



Phosphoric acid ... *110 



This soil was free from chlorides and did not receive any 

 manure. 



