NOTES ON THE HYDROCYANIC-ACID CONTENT OF 



SORGHUM 



By J. J. WiLLAMAN and R. M. West, Assistant Chemists, Agricultural Experiment 

 Station of the University of Minnesota 



INTRODUCTION 



In the course of our work on the chemistry of Sorghum vulgare it was 

 thought desirable to study its content of hydrocyanic acid (HCN) under 

 Minnesota conditions. Many instances are on record of the poisoning of 

 cattle from feeding on growing sorghum cane, and some of these cases • 

 have been definitely proved to be due to hydrocyanic acid, which occurs 

 in sorghum as a constituent of the glucosid dhurrin (6).^ 



The factors which affect the amount of this glucosid in the plant have 

 received some attention. All investigators have found that it decreases 

 as the plant matures. Maxwell (8) states that sorghum is not fed with 

 safety until after the seeds begin to develop; Briinnich (4), that it should 

 not be fed until the seeds are fully matured. Avery (2) says that the 

 amount of hydrocyanic acid is greater in stunted plants, while Alway 

 and Trumbull (i) found that yellow, stunted plants contained less of the 

 acid than the green, vigorous plants in the same field. Maxwell (8) 

 believes that the amount of the glucosid is dependent on the character of 

 the soil, soils rich in nitrogen producing plants richer in the glucosid. 

 Briinnich (4), in experiments with sodium nitrate in Queensland, found 

 that the fertilized plants contained slightly more hydrocyanic acid 

 than those unfertilized and concluded that heavy nitrogenous soils 

 and favorable climatic conditions increase the amount of the acid. His 

 findings were corroborated by Alway and Trumbull (i). Briinnich (5) 

 also found that millet {Panicutn miliaceum) behaved similarly to sorghum. 

 Schroder and Dammann (10), in Uruguay, report an increase in prussic 

 acid due to the use of sodium nitrate as a fertilizer. Balfour (3) noticed 

 that plants infected with Aphis sorghi contained more hydrocyanic acid 

 than uninfected plants. These are the main facts which have been 

 published in the literature concerning the occurrence of a cyanogenetic 

 glucosid in sorghum. 



Samples of the 191 3 crop of cane grown on the farm of the University 

 of Minnesota were analyzed about the middle of August, and the acid 

 was found to be absent in all cases. As it has often been proved to 

 persist in the plant to a later period, this result was considered unusual, 

 and it was decided to repeat the work the next season. On analyzing 

 a sample of plants 6 inches high, taken on June 26, 1914, hydrocyanic 



I Reference is made by number to "Literature cited," p. 185. 



Journal of Agricultural Research, Vol. IV, Ko. 2 



Dept. of Agriculture, Washington. D. C. ^'^V '5. I'JiS 



Minn. — 3 



(179) 



