HARMFUL EFFECTS OF ALDEHYDES IN SOILS. 



11 



Phosphate. — The amount of phosphate, stated as P 2 5 , removed 

 from the total number of solutions during the experiment was 395.7 

 milligrams for the normal cultures and 344.2 milligrams for the cul- 

 tures containing salicylic aldehyde. The salicylic aldehyde cultures 

 absorbed 51.5 milligrams of P 2 5 less than the normal cultures. 



Nitrate. — The total amount of nitrate, stated as NH 3 , removed 

 from the total number of solutions during the course of the experi- 

 ment was 578.3 milligrams for the normal cultures and 454.9 milli- 

 grams for the salicylic aldehyde cultures. The salicylic aldehyde 

 cultures used 123.4 milligrams less nitrate. 



Potassium. — The amount of potash, stated as K 2 0, absorbed by the 

 plants in the total number of cultures was 672.6 milligrams in the 

 case of the normal cultures and 533.2 milligrams for the cultures with 

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

 aldehyde cultures absorbed less potash, there being a difference of 

 139.4 milligrams 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 

 influence of the salicylic aldehyde. This would appear to be in 

 harmony 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 effect of salicylic aldehyde under physiologi- 

 cally alkaline conditions, an experiment was made in nutrient culture 

 solutions containing calcium carbonate. The cultures were prepared 

 as in the experiments already recorded. The solutions were composed 

 of calcium acid phosphate, sodium nitrate, and potassium sulphate 

 in different proportions. Salicylic aldehyde was used in quantities 

 of 10 parts per million, and 100 milligrams of calcium carbonate were 

 added to each culture in the control set and in the salicylic aldehyde 

 set. The plants grew from March 23 to April 4, 12 days. The solu- 

 tions were changed every three days. The green weights of the 

 plants grown in solutions without and with salicylic aldehyde are 

 given in the fourth and fifth columns of Table VIII. 



Table YTil.— Effect of salicylic aldehyde in nutrient cultures containing calcium carbonate. 



Composition of nutrient 

 solution. 



Without 

 salicylic 

 aldehyde. 



With 



salicylic 



aldehyde, 



10 parts 



per 

 million. 



Composition of nutrient 

 solution. 



Without 

 salicylic 

 aldehyde. 



With 

 salicylic 

 aldehyde, 

 10 parts 



per 

 million. 



r 2 o 5 



NH 3 



K 2 



Green 



weight. 



Green 



weight. 



P 2 5 



NH 3 



K2O 



Green 

 weight. 



Green 

 weight. 



Parts per 



million. 



48 



64 



16 



Parts per 



million. 



16 



8 



48 



Parts per 



million. 



16 



8 



16 



Grams. 

 2.85 

 2.00 

 3.19 



Grams. 

 1.95 

 1.95 

 2.45 



Parts per 



million. 



8 



16 



8 



Parts per 



million. 

 64 

 16 

 8 



Parts per 



million. 



8 



48 



64 



Grams. 

 2.70 

 3.55 

 3.60 



Grams. 

 2.45 

 2.55 

 2.05 



