132 



Journal of Agricultural Research voi. xxn.No. 3 



This shows that it is possible to obtain some hydrocyanic acid from the 

 uncut green grass if the time of digestion is sufficiently long. In every 

 case more was obtained when the material was cut in the feed cutter and 

 still more when it was macerated. Hot water placed on the green mate- 

 rial entirely prevented liberation. The small amount obtained from the 

 partially wilted grass when the hot water was added was probably in a 

 free condition at the time of adding the hot water. Almost as much 

 hydrocyanic acid was obtained from the grass that was wilted seven hours 

 as from the fresh grass if digested in water at room temperature suffi- 

 ciently long. 



This experiment as well as several others show that under some 

 circumstances it is possible to obtain hydrocyanic acid from wilted or 

 dried grass both with and without digestion in either hot or cold water. 

 To investigate this further the following experiment was planned and 

 executed. Five sets of 12 samples were secured and treated as follows: 

 (i) Dried in the sun; (2) dried in the shade; (3) exposed in the sun, 

 but kept moist by frequent sprinkling with water; (4) exposed in the 

 shade but kept moist by sprinkling with water; (5) frozen in an ice 

 machine and then exposed in open pans in the shade. The duration 

 of these treatments was for 4, 8, 24, 31, and 48 hours, respectively. 

 Six of the samples from each set were macerated after the period of 

 the preliminary treatment, and hot water was poured on and distilled 

 at once. The other six were digested in cold water overnight and then 

 distilled. The results are shown in Table XL 



Table XI. — Rate of disappearance of hydrocyanic acid from Sudan grass after it is cut 



and variously handled <i 



" The figures indicate milligrams of hydrocyanic acid from 200 gm. of grass and are averages of several 

 determinations. 



The results show that no hydrocyanic acid is obtained from green 

 material when treated with hot water very soon after cutting and mac- 

 erating, but that when the grass is wilted as much as four hours in the 

 sun, considerable hydrocyanic acid is obtained by treating with hot 

 water immediately after maceration. The amount of hydrocyanic acid 



