go6 Hydrocyanic Acid from Linseed Cake, [feb., 



M.R.C.V.S., we were able to carry out feeding tests on sheep 

 and on a heifer, which had for their primary object the 

 elucidation of obscure cases of blindness affecting heifers. 

 Incidentally, it was hoped to solve the question of the harm- 

 fulness or otherwise of the cake. 



The results are here briefly summarised (HCN = Hydro- 

 cyanic acid) : — 



I. — A sheep had i lb. cake (0*025 per cent. HCN) per diem 

 for 36 consecutive days. No result. 



II. — A sheep had 1 lb. for 31 days; 5 lb. for 2 days; and 

 after 7 days a further 5 lb. No result. 



III. — A heifer (six months) had : — 



1 lb. per day dry cake for 4 days. 



1 lb. per day moist cake for 13 days. 



2 lb. per day moist cake for 2 days. 

 5 lb. per day moist cake for 18 days. 



14 days' interval. 



5 lb. per day moist cake for 30 days. 



Total 261 lb. cake in 67 days equal to 45675 grains of 

 hydrocyanic acid. 



No definite results having been obtained, the cake was 

 discontinued, and after about six weeks acid in the form of 

 pure potassium cyanide (KCN) was fed as follows : — 



KCN equiv. to 3*5 grains HCN in ordinary food 4 days. 



KCN equiv. to 7 0 grains HCN in ordinary food 1 day. 



KCN equiv. to io'o grains HCN in ordinary food 1 day. 

 Interval 2 days. 



KCN equiv. to 15*0 grains HCN in ordinary food 2 days. 

 Total 6i*o grains HCN in 10 days. 



No obvious results were got. The animal at first refused 

 the larger doses, but ate the food within an hour. 



Fifteen grains hydrocyanic acid were then fed with 7 lb. 

 of bran in one feed, and next day a further 15 grains, in this 

 case liberated from the salt by an equivalent amount of dilute 

 hydrochloric acid. No notable result was got. 



After eight days, cyanide equivalent to 22*5 grains hydro- 

 cyanic acid were given in a gentian ball inserted into the 

 rumen, and as no notable result ensued next day 30 grains 

 were similarly administered. This proved fatal within two 

 hours. 



