400 Effect of Salicylic Aldehyde on Plauts [April-July 



to compare the results obtained in the normal cultures without sali- 

 cylic aldehyde and in the cultures where lo p.p.m. of salicylic alde- 

 hyde were present in the Solution. 



The sum total of P2O5, NH3 and KoO removed from Solution 

 by the growing plants in all of the cultures under study was 1646.6 

 mg. in the normal cultures and 1332.3 mg. in the nutrient cultures 

 containing salicylic aldehyde. The figures show the total of plant 

 nutrients removed to be less in the cultures containing salicylic 

 aldehyde than in the normal cultures, which indicates that the sali- 

 cylic aldehyde cultures used less nutrients than the normal. An 

 examination of the results pertaining to the three constituents sepa- 

 rately are given below. 



Phosphate. The amount of phosphate, stated as P2O5, that was 

 removed from the total number of Solutions during the experiment 

 was 395.7 mg. for the normal cultures and 344.2 mg. for the cul- 

 tures containing salicylic aldehyde. The salicylic aldehyde cultures 

 absorbed 51.5 mg. of P2O5 less than the normal cultures. 



Nitrate. The total amount of nitrate, stated as NH3, that was 

 removed from the total number of Solutions during the course of the 

 experiment was 578.3 mg. for the normal cultures and 454-9 mg- ^or 

 the salicylic aldehyde cultures. The salicylic aldehyde cultures used 

 123.4 mg. less nitrate. 



Potassium. The amount of potash, stated as K2O, that was 

 absorbed by the plants in the total number of cultures was 672.6 mg. 

 in the case of the normal cultures and 533.2 mg. for the cultures 

 with salicylic aldehyde. As with the phosphate and nitrate, the 

 salicylic aldehyde cultures absorbed less potash, there being a dififer- 

 ence of 139.4 mg. in favor of the normal cultures. 



An examination of the above figures shows a more nearly normal 

 absorption of phosphate than of the nitrate or potash under the in- 

 fluence of the salicylic aldehyde. This would appear to be in har- 

 mony with the relatively lessened toxicity of the aldehyde in the 

 mainly phosphatic nutrient Solutions. 



Effect of calcium carbonate on the action of salicylic 

 ALDEHYDE. In Order to study the physiological effect of salicylic 

 aldehyde under alkaline conditions, an experiment was made in 

 nutrient culture Solutions containing calcium carbonate. The cul- 



