1 915] 



MERRILL DISTILLED WATER 



473 



full nutrient solution the entire period. However, plants 

 which had been in distilled water only 5 days before being 

 transferred to full nutrient solution subsequently equalled in 

 growth other plants which had been in the latter medium from 



TABLE III (Series 2) 



EFFECT OF RENEWED VS. UNRENEWED MEDIA ON GROWTH OF PEAS 





Length of 



Dist. H 2 



Length of 



Full nutr. 



Green wt. 



Dry wt. 



Culture 



period in 



renewed or 



period in 



renewed or 



of 



of 



no. 



dist. H 2 



unrenewed 



full nutr. 



unrenewed 



tops 



roots 





days 





days 





gms. 







gms. 



1 



47 

 47 

 47 

 47 



1 



Unrenewed 



Unrenewed 



Renewed 



Renewed 



Unrenewed 







.80 



.60 



.45 



1.30 



6.75 



.073 



2 







.076 



mm 



3 







.067 



4 







.091 



-A 



5 



32 



Unrenewed 



.400 



6 



1 



Unrenewed 



32 



Renewed 



11.05 



.500 



7 



2 



Unrenewed 



31 



Unrenewed 



5.50 



.401 



8 



2 



Unrenewed 



31 



Renewed 



12.90 



.568 



9 



5 



Unrenewed 



28 



Unrenewed 



5.95 



.263 



10 



5 



Unrenewed 



28 



Renewed 



12.35 



.467 



11 



10 



Unrenewed 



23 



Unrenewed 



5.35 



.254 



12 



10 



Unrenewed 



23 



Renewed 



7.90 



.321 



13 



10 



Renewed 



23 



Unrenewed 



3.80 



.160 



14 



10 



Renewed 



23 



Renewed 



6.07 



.202 



15 



15 



Unrenewed 



18 



Unrenewed 



3.30 



.144 



16 



15 



Unrenewed 



18 



Renewed 



4.40 



.175 



17 



15 



Renewed 



18 



Unrenewed 



4.30 



.162 



18 



15 



Renewed 



18 



Renewed 



4.15 



.169 



19 



20 



Unrenewed 



13 



Unrenewed 



3.21 



.124 



20 



20 



Unrenewed 



13 



Renewed 



2.52 



.092 



21 



20 



Renewed 



13 



Unrenewed 



4.05 



.139 



22 



20 



Renewed 



13 



Renewed 



4.43 



.141 



23 







33 

 33 

 33 

 33 



Unrenewed 

 Unrenewed 

 Renewed 

 Renewed 



5.50 

 6.94 

 9.60 



13.45 



.368 



24 







.420 



25 







.536 



26 







.611 



the start. The period between 5 and 10 days in distilled water 

 is therefore a critical one, and will be discussed later in other 



connections. 



Renewing the full nutrient solution again showed beneficial 

 results, as might be expected. But the renewal of the distilled 

 water did not produce such striking results in some respects 

 as in the case of the horse beans ; in other ways, however, the 

 results were equally or even more striking. Where the plants 

 remained in distilled water for 47 days the growth was better 

 in one case and poorer in the other where the distilled water 

 was renewed than where it was not renewed. The average 



