EXPERIMENTS ON VEGETATION IN SOLUTIONS. 377 



IV. Period. From Jul}' 27 to August. 1. — At the commence- 

 ment the plant weighed 147 grammes, had eleven leaves, with a 

 surface of 1 1 60 square centimetres ; water exhaled = 1 litre ; 

 to the solution was added 0*1 gramme of phosphate of iron ; the 

 roots became distinctly reddish yellow. The plants received 

 tvdce as much KOPOj as in the second period. 



ABC 

 Nitric acid .... 1-0800 ? ? 



Sulphuric acid 

 Phosphoric acid . 

 Lime 



Magnesia 

 Potash . 



0-2475 0-1374 0-1101 



0-1250 0-0000 0-1250 



0-3420 0-1188 0-2232 



0-1165 0-0719 0-0446 



0-5518 0-1296 04222 



2-4628 0-4617 0-9211 



Proportions between bases and acids, — 



Given: = 2-9; =1-6: 1 = 2-1 



MgO CaO MgO 



Absorbed: -—— -=5-0: =1-8; 1- = 2-3 



MgO CaO ' MgO 



To ascertain how far the results from this artificial mode of 

 cultivation maybe compared with those produced under natural 

 circumstances, maize of the same kind was planted in the 

 garden in the middle of May. The latter were exposed to the 

 same atmospheric conditions as the experimental plants. On 

 August 1, a plant from the garden of the same period of 

 vegetation as the experimental plant, with also fifteen leaves, 

 and visible male flowers, weighed 1260 grammes, that is to say, 

 seven times as much as the artificially reared plant. The stem 

 of the garden plant from the lower knot to the summit of the 

 flower-stalk measured 150 centimetres, being three times the 

 height of the experimental plant. 



V. Period. P'rom August 1 to 10. — At the commencement 

 the plant weighed 173 grammes ; the stem was 52 centimetres 

 high ; in the middle of the period the plant had fifteen large 

 fine green leaves, with a surface of 1420 square centimetres. 

 In this period double the quantity of water (2 litres) was 

 exhaled, and as the older roots were distinctly reddish yellow in 

 colour, the plant received no more phosphate of iron, but thrice 

 as much phosphate of potash as in the second period. On 



