176 Journal of Agricultural Research voI.xvi.no. 7 



maltose on the liberation of the hydrocyanic acid from the glucosid; and, 

 fourth, to determine whether or not the hydrocyanic acid may be present 

 in more than one form as has been claimed by Willaman {10). While 

 these are the main points studied, there are several others, possibly of 

 minor importance, that were studied. 



EXPERIMENTAL WORK 



Four different samples of sorghum were used. One was a sample ob- 

 tained from Mr. Ed. Singleton, of Chickasha, Okla., and was a part of 

 a lot of sorghum which had been cut when it was about 2% feet high and 

 at a time when there was an extreme drouth in the southwestern part of 

 the State. This was a part of some sorghum which had been fed to 12 

 head of cattle, 10 of which had died within one hour. This will be called 

 sample i. Sample 2 was cut at the same stage of growth by Mr. P. A. 

 Gould, of Stillwater, but had not been subjected to as extreme drouth 

 as sample i, as it was cut at the beginning of the dry weather. Sample 3 

 was a second-growth sorghum which had grown after heavy rains had fallen 

 and there had been plenty of moisture in the ground all during its growth. 

 This sample was cut fresh each time as it was needed and was about 

 knee-high at the time of cutting. Sample 4 was a volunteer sorghum 

 cut from the Experiment Station farm. This sample was in the dough 

 stage when cut, but it had been subjected to the dry weather of the 

 summer and had grown quite vigorously after the rains had fallen. 



The method of determining the hydrocyanic acid was a modification 

 of that used by Viehoever and Johns (9) and by Knight (5). In the case 

 of the dry samples Nos. i and 2, the sorghum was cut into fine pieces and 

 then run through a feed mill. Samples 3 and 4 were cut a little at a time, 

 this part being thoroughly wet and bruised in a large iron mortar. The 

 bruised portions were placed in water in the digestion flask. At first 

 each of these samples were kept in the digestion flask in a water bath at 

 40° C. for two hours, the apparatus being so arranged that any hydro- 

 cyanic acid which passed off would be collected in sodium hydroxide. 

 After this period of digestion the water bath was removed, and 100 

 cc. were distilled as rapidly as possible, the hydrocyanic acid being 

 collected in sodium hydroxid. It was found by two or three trials that all 

 of the hydrocyanic acid was driven over by distilling 100 cc. At first 

 the distillate was evaporated in vacuum as directed by Viehoever and 

 Johns (9), but since this required such a long time it was decided to 

 carry on the evaporation by placing the distillate in a flat-form evapora- 

 tion dish on a water bath which was heated by an electric hot plate. 

 A current of air from an electric fan at a low speed was directed across 

 the evaporating dish. It was found that under these conditions the solu- 

 tion was usually at aboiit 60° C. and in no case did the temperature go 

 above 70° C. With such an arrangement the evaporation could be made 

 easily within two hours. After the distillate was evaporated almost to 



