I30 



Journal of Agricultural Research voi. xxii. no. 3 



TablR YII. — Disappearance of hydrocyanic acid from Sudan grass after cutting 



Date collected. 



Sample 

 No. 



Treatment. 



HCN. 



June 29 



July 7. 



Aug. 12 

 Sept. I. 



\Vilted in shade 



Green , control sample 



Wilted in sun for three hours 



Dried in sun from morning till evening, outdoors over 



night 



Dried in shade for same length of time as 2 



Dried outdoors two days and nights 



Dried in the shade two days and nights 



Dried in shade tliree da)'s and nights 



Dried in the shade five days 



Dried in the shade two days 



Mgm. 



28 

 36 



15 

 24 



IS 



7 



20 



32 

 6 



While these results are not uniform, they do show conclusively that 

 hydrocyanic acid can be obtained from wilted grass. Because of this 

 result an attempt was made to determine more accurately the amount of 

 hydrocyanic acid that may be obtained from wilted and dried grass. 



EFFECTS OF KEEPING GREEN GRASS MOIST AFTER IT IS CUT 



A large sample of grass collected June 29 was placed stems down in a 

 large bottle so that about one-fourth was immersed in water. At the 

 end of different periods of time 200-gm. portions of the leaves were mac- 

 erated and digested in water overnight. The amount of hydrocyanic 

 acid obtained is given in Table VIII. 



The results indicate that hydrocyanic acid slowly disappears from the 

 grass after it is cut, but also that the grass may be kept for a while in the 

 green condition without much loss of the hydrocyanic acid. Control 

 samples taken at this time gave 30 mgm. hydrocyanic acid. 



When the grass was wholly covered with water or when the air was 

 excluded the results were different. In each case in the experiment re- 

 ported in Table IX, unless otherwise stated, the grass was macerated and 

 digested at the end of the treatment given. 



This shows that the presence or absence of air has an intimate relation 

 to the evolution of hydrocyanic acid. Experiments were performed in 

 which the grass was kept in an atmosphere of carbon dioxid and also of 



