Feb. 17, I9I9 Cyanogenesis in Andropogon sorghum 179 



DISCUSSION OF RESULTS 



Any discussion of the experimental results will necessarily be of the 

 nature of a summary. A comparison of the percentage of hydrocyanic 

 acid found in experiments la and ib w-ith those in 2a and 2b shows that 

 approximately three-fourths of the acid is set free in the process of drying. 

 This goes to confirm the common belief that sorghum is safe for feeding 

 after it has been dried. At the same time the results show that not all 

 of the hydrocyanic acid disappears. A comparison of experiments 2a 

 and 2b with 3a and 3b shows that the rapidity with which the sorghum 

 is d*^ed determines the percentage of the hydrocynaic acid that is re- 

 tained by it. This point is of considerable importance in Oklahoma on 

 account of the fact that farmers quite frequently cut their sorghum 

 during drouths after it has been partially dried while yet standing; and 

 after it is cut, being already partly dry, it dries very quickly. Under 

 such conditions a large percentage of the hydrocyanic acid would be 

 retained in the fodder. Sample i was cut under such conditions. 



A glance at experiments 4, a, b, c, and d, will show that the enzym 

 which is present in the sorghum is still active and that the addition of 

 emulsin does not cause the hydrocyanic acid to be liberated in greater 

 quantity. 



A comparison of the amount of hydrocyanic acid found in experiments 

 5a and 5b with experiment 4 shows that the addition of such a small 

 quantity as i per cent of dextrose and i per cent of maltose seems to 

 hold back or prevent the liberation of about three-fourths of the acid. 

 This is an extremely important result from the practical standpoint. 

 Dextrose and maltose were selected because of the fact that they are 

 formed by the action of the pytalin on the starches in the paunch. This 

 retention of the hydrocyanic acid in the presence of these sugars may be 

 assumed to be due either to a reaction between the sugars (aldehydes) 

 and hydrocyanic acid or to a lessening of the activity of the enzym by 

 the sugars. This would lead to the suggestion that in case there is any 

 doubt about the poisonous nature of the sorghum one should feed some 

 concentrate before feeding the sorghum. In this way a considerable 

 quantity of dextrose and maltose would be produced by the salivary 

 digestion and would tend te prevent liberation of the hydrocyanic acid 

 of the sorghum which is fed afterwards. At the time of this experiment 

 I had not read Peters, Slade, and Avery's work (6), in vrhich they showed 

 that it was possible to give very large doses of hydrocyanic acid without 

 any harmful effects provided at the same time a somewhat proportionate 

 amount of dextrose was given. 



It has been claimed by Willaman, as has already been stated, that 

 the hydrocyanic acid exists in the sorghum in two forms — glucosidic 

 and nonglucosidic. It seems natural to suppose that the nonglucosidic 

 acid would not be liberated under the conditions that existed in my 



