1915] 



MERRILL DISTILLED WATER 



469 



no doubt, to an increased amount of available nutrients. But 

 an interesting comparison is manifest in connection with the 

 effect of renewing the distilled water; the greater growth of 

 both tops and roots may be noted in cultures 3 and 4, in which 



TABLE I (Series 1) 



EFFECT OF RENEWED VS. UNRENEWED MEDIA ON GROWTH OF HORSE BEANS 



/"* 1 



Length of 



Dist. H 8 



Length of 



Full nutr. 



Green 



Dry wt. 



Dry wt. 



Culture 



period in 



renewed or 



period in 



renewed or 



wt. of 



of 



of 



no. 



dist. H 2 



unrenewed 



full nutr. 



unrenewed 



tops 



tops 



roots 





days 





days 





gms. 



gms. 



gms. 



1 



45 

 45 

 45 

 45 



1 



Unrenewed 



Unrenewed 



Renewed 



Renewed 



Unrenewed 







2.15 

 1.75 

 4.40 

 4.40 

 16.30 



.777 

 .666 

 .887 

 .870 

 2.069 



.124 



2 







.096 



3 







.272 



4 







.235 



5 



44 



Unrenewed 



.485 



6 



1 



Unrenewed 



44 



Renewed 



27.00 



3.069 



.707 



7 



2 



Unrenewed 



43 



Unrenewed 



15.85 



1.994 



.429 



8 



2 



Unrenewed 



43 



Renewed 



32.51 



3.543 



.743 



9 



5 



Unrenewed 



40 



Unrenewed 



18.90 



2.315 



.463 



10 



5 



Unrenewed 



40 



Renewed 



26.25 



2.895 



.700 



11 



10 



Unrenewed 



35 



Unrenewed 



13.35 



1.623 



.382 



12 



10 



Unrenewed 



35 



Renewed 



26.35 



2.928 



.697 



13 



10 



Renewed 



35 



Unrenewed 



14.90 



1.887 



.463 



14 



10 



Renewed 



35 



Renewed 



22.90 



2.376 



.548 



15 



15 



Unrenewed 



30 



Unrenewed 



14.00 



1.719 



.388 



16 



15 



Unrenewed 



30 



Renewed 



18.05 



1.880 



.457 



17 



15 



Renewed 



30 



Unrenewed 



15.60 



1.807 



.417 



18 



15 



Renewed 



30 



Renewed 



21.20 



2.403 



.642 



19 



20 



Unrenewed 



25 



Unrenewed 



12.51 



1.447 



.300 



20 



20 



Unrenewed 



25 



Renewed 



11.40 



1.247 



.328 



21 



20 



Renewed 



25 



Unrenewed 



11.40 



1.319 



.284 



22 



20 



Renewed 



25 



Renewed 



15.50 



1.670 



.454 



23 







45 

 45 

 45 



45 



Unrenewed 



Unrenewed 



Renewed 



Renewed 



14.60 

 14.70 



27.85 

 27.05 



1.975 

 2.044 

 2.925 

 3.025 



.419 



24 







• ^^ ^» ^ 



.443 



25 







.690 



26 







.764 



^^^» ^^ 







• W ^-^ *^ 



the distilled water was renewed every four days throughout 

 the period, as compared with that of cultures 1 and 2, where 

 the distilled water was not renewed, except, of course, for the 

 occasional addition of water to replace the transpiration loss, 

 which, however, was small. Furthermore, in noting the 

 growth of cultures 11-22 inclusive, it is seen that in four of 

 the six cases of comparison between the renewed and unre- 

 newed distilled water, better growth of both tops and roots 

 resulted where the distilled water was renewed. Considering 

 cultures 1-4 and 11-22, inclusive, the total green weight of 

 tops for the unrenewed distilled water as compared with the 



