PROCEEDINGS OF THE COTTESWOLD CLUB I09 



Each pot received as plant food the first three ingredients 

 of the mixture given above, namely : 



Grammes 



Potassium phosphate - - - '5444 

 Potassium chloride - - - - '1492 

 Magnesium sulphate - - - - '2400 



and at the same time a quantity of Calcium Nitrate 

 varying with each pot or set of pots as follows : 



Grammes 



I pot received i'968 



3 pots „ r3i2 



I pot „ "984 



3 pots „ '656 



3 pots „ "328 



1 pot „ ... - - -164 



2 pots „ 000 



In brief, while two of the pots had no Nitrogen 

 whatever given to them, the rest had varying quantities, 

 duly noted by the numbering of the pots. This plan was 

 followed throughout and need not be again described in 

 detail. 



For the first week all grew equally well, but then it was 

 noticed that in the pots receiving no Nitrogen the plants 

 were suddenly checked in their growth, and as the days 

 went on this retardation became more marked. In a 

 fortnight the four pots which had received the smallest 

 quantity of Nitrogen exhibited a similar sudden retardation 

 of growth, and by the end of the third week the effects of 

 the varying quantities of Nitrogen were quite plain, not 

 only in the vigour of the plants, but in the quantity of 

 leaf, stem, ear and grain produced. It was clear that 

 the growth was directly proportional to the amount of 

 Nitrogen supplied in the Calcium Nitrate. The most 

 thorough and careful analyses were made of the produce 

 from each pot, and the results duly tabulated. 



