1915] 



MERRILL DISTILLED AVATER 



487 



that in the interim the 



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After the 10th day the curve inclined with fluctuations. Here 

 again are seen evidences that the 10-day period for seedlings 

 in the distilled water may properly be considered a crucial 

 one for the plants. After that time the growth declines and 

 the conductivity increases markedly. 



Suspecting that the question of injury to plants in distilled 



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Fig. 2. The conductivity and growth curves 

 redistilled water in which pea seedlings were grown 

 complete explanation see the text.) 



for 

 for 



the unrenewed 

 50 days. (For 



water might be intimately bound up with that of lack of 

 reserve food materials, the writer carried out an experiment 

 bearing upon this matter. The experiment consisted, first, 

 in placing some Canada field pea seedlings directly into redis- 

 tilled water and determining the specific conductivity of the 

 water at intervals for 20 days ; and, next, in transferring some 

 pea plants which had been grown in full nutrient solution for 

 1, 5, 10, 20, 30, and 40 days respectively to redistilled water, 

 and determining the specific conductivity of the water at in- 

 tervals for 20 days. The results are plotted as curves in 

 fig. 3, the conductivity values being represented in terms of 

 x on the Wheatstone bridge with a resistance of 9,110 ohms in 

 the box. Four cultures of 10 plants each (except in the case 



