May 13. 1918 Chemistry of the Cotton Plant 349 



ISOLATION OF QUERCIMERITRIN FROM THE LEAVES 



The leaves were treated according to Perkin's original method, as 

 follows: Air-dried, pulverized cotton leaves (1,500 gms.) were heated 

 with alcohol in an aluminum kettle for 4 hours on a steam bath. After 

 cooling, the extract was pressed out and the dark-green liquid evaporated 

 in a vacuum still to a small volume. Hot water was then added, and the 

 distillation was continued until all the alcohol was removed. The hot 

 mixture was then allowed to stand for about an hour, when an upper 

 layer of black tar formed. The warm aqueous solution underneath was 

 siphoned off and filtered through paper pulp. To remove chlorophyll 

 and waxy matter, the cooled siphonate was twice extracted with ether, 

 and the resulting clear, red, aqueous solution heated to expel any re- 

 maining ether. Lead-acetate solution was then added, and the thick 

 orange-yellow precipitate that formed was filtered off by suction and 

 washed with water. The lead was then removed from this precipitate 

 by mixing it with hot water to make a thin paste, through which hydrogen 

 sulphid was passed. The lead sulphid was filtered off by means of paper 

 pulp. The clear, red filtrate was evaporated to a small volume and 

 allowed to stand for several days, when a yellow amorphous substance 

 slowly separated. Several fractions of this material were further obtained 

 from the mother liquor. These fractions consisted of much quercetin 

 and a little quercimeritrin. By a series of recrystallizations from water 

 dilute alcohol, dilute acetic acid, and from pyridin, the quercimeritrin 

 was obtained in a comparatively pure state. The quercimeritrin thus 

 obtained melted at 247° C. When hydrolyzed with 5 per cent sul- 

 phuric acid, it gave quercetin. The latter compound was identified by 

 the fact that it gave an acetyl derivative melting at 1 94° C. A mixture of 

 quercimeritrin from the petals and from the leaves also melted at 247° C. 



ISOLATION OF QUERCIMERITRIN FROM THE FLOWERS WITH PETALS 



REMOVED 



These parts of the plant, treated in the same manner as the leaves, 

 also gave quercimeritrin melting at 247° C. 



II.— THE ETHEREAL OIL 



While a volatile oil had previously been isolated in small amounts from 

 the bark of the root of Gassy pium herhaceum by Power and Browning (5), 

 none had been reported from aboveground parts of this plant nor of 

 other species of Gossypium. 



The first intimation that a volatile oil might be present in plants of the 

 Upland cotton was obtained by observing that a steam distillate of the 

 leaves proved to be attractive to the boll weevil. The amount of oil 

 found in the leaves or young plants was very small. In over 4,000 

 pounds of fresh plants only about an ounce of volatile oil was secured, 

 amounting to 0.0015 per cent on an average. 



