VOLATILE COMPONENTS OF GREEN LEAVES 



253 



leaves to steam distillation, while Franzen (1920) worked with a similar 

 quantity of oak leaves. The distillates were fractionated, and it was 

 found that hexenaldehyde is only the most abundant of many volatile 

 components — acids, aldehydes, and alcohols — Hsted in table 10.11. 



Table 10.11 

 Volatile Components of Green Leaves 



Component 



Hornbeam 



Chestnut 



Oak 



Aldehydes 



Alcohols 



"Curtius and Franzen (19123, 1913) at first considered the presence of formic acid in AgzO-oxidized 

 aldehyd^alcohol fraction as a proof of the occurrence of formaldehyde in leaves; but this conclusion was 

 criticized by Fincke (1913). Later, Curtius and Franzen (1915) acknowledged that formic acid can be 

 formed also by oxidation of methanol. 



The acids were precipitated with baryta. The aldehydes in the filtrate were 

 oxidized with silver oxide, and the acids formed in this way also precipitated as barium 

 salts. The filtrate was distilled, and the oil drops in the distillate extracted with ether; 

 this fraction contained the alcohols. 



Franzen, Wagner, and Schneider (1921) found that the steam distillate 

 (from 28 leaf species) also contains basic components, predominantly 

 ammonia. Franzen and Wagner (1920) distilled small portions (1 kg.) 

 of leaves of 40 species and found that in all of them the presence of 



