46 Cyanogenesis in Sorghum vulgare Hydrocyanic acid in dura Sennar Atbara Reports on poisonous dura Gezira Reverting to the subject of dura, mention must be made of another matter relating to it which has claimed attention. This is the presence of hydrocyanic acid in dura used as fodder, and the fatality resulting amongst animals fed on such dura.

Attention was directed to the subject by reading accounts of the discovery by Dunstan and Henry1 of a glucoside, “dhurrin,” contained in the young plants of the sorghum, which on decomposition in the presence of water yields free hydrocyanic acid. This is said to explain the numerous cases of sudden death occurring among cattle fed on immature sorghum. The analytical work of Brunnich2 on the same subject, and the observations of Dr. Maxwell, and Veterinary-Inspector Quinnel3 in Australia, show how important it is, and accordingly, through the medium of the Secretary General one collected as much information as could be gathered from various parts of the Sudan, and proceeded to examine some specimens of dura in which no difficulty was experienced in detecting the poisonous acid. The answers to the enquiries are interesting, and may with advantage be briefly stated here.

Colonel Gorringe reported from Sennar that there had been no recent casualties among animals from this cause, but recalled a considerable loss in horses and cattle at Iverreri in 1898, from their having been fed on green dura about one foot high.

He states that the natives in his district regard it as harmless when dry, and do not give it when green till the seed ears are well developed. Mr. Neville, from the Atbara district, furnished much important information, and recorded his opinion that dura of normal growth is absolutely innocuous to animals in the Sudan. He also stated that the variety known as Peterita is the most poisonous, and that more deaths result from animals eating u hantout ” and other poisonous grasses than from dura. The most fatal condition, he says, and the most common in the Sudan, is produced when animals are fed on dura which has been stunted from lack of rainfall and has then grown rapidly when water was obtainable. Natives, he further states, are well aware of the danger, and believe that only ruminants suffer and that donkeys and horses may feed on such dura with impunity. Colonel Stanton, however, informed me that on one occasion his horse, although well and hungry, and though he expected it to feed greedily on some tempting green dura, refused to touch it. 1 ossibly animals of a higher intelligence than cattle may recognise and a\oid the danger. Mr. Neville also enters into a consideration of other ill-effects pioduceci by dura such as colic and kidney troubles, due to the presence of large quantities of potassium nitrate in the plants.

Major Dickinson, Gezira, gave evidence which coincides with that of Mr. Neville, and mentioned fatal cases occurring at Wad Ramleh in 1902. Some 1 Phil. Trans.. 1901 Series, B 515, and 1902 Series, A 399 2 Journal Chemical Society, July, 1903 3 Injurious effect of sorghum on stock. Paper Agric. Con., Queensland, June, 1902