112 



BOTANICAL GAZETTE 



[FEBRUARY 



extraction with ether, then treatment of the finely ground material 

 with hot water several times, after which the aqueous mixture was 

 made up to a concentration of 75 per cent alcohol and filtered. 

 The insoluble material was then subjected to further extraction 

 with hot alcohol for 24 hours. 



The combined extractions were evaporated to dryness on a 

 steam bath, then repeatedly evaporated with absolute ethyl 

 alcohol in order to remove water. The dry hard residue was then 



Fig. 9. — Effect of heavy N fertilization: no. 12, normal N (warm house); no. 85, 

 heavy N (cool house); no. 22, heavy N (warm house); no. 75, normal N (cool house). 



extracted with anhydrous ether by grinding with a pestle with suc- 

 cessive portions of fresh ether.- The ethereal extracts were made 

 up to 250 cc, and then divided into suitable aliquots for chemical 

 and dry weight determinations (50 cc. portions). This extraction 

 was designated as fraction 1 (F r ). The ether- insoluble residue 

 was taken up in about 65 per cent alcohol and made up to a volume 

 of 500 cc, 50 cc. portions being taken as aliquots for analysis and 

 dry weight determinations. This was designated as fraction 2 (F 2 ). 

 Moisture determinations were made on duplicate F t and F 2 aliquots 



