282 QUEENSLAND AGRICULTURAL JOURNAL. [1 Ocr., 1902. 
Animal Pathology. 
SORGHUM POISONING. 
So many inquiries have reached the Department of Agriculture as to the 
cause of the death of stock depastured on young growing sorghum, and as to 
what remedies are known for the alleged poisonous effects of the forage, that 
any light which can be thrown on the question cannot fail to be of great 
interest to stockowners. 
Much attention has been devoted by the scientists of the Department to 
the matter, with the view of establishing the existence or non-existence of a 
poisonous element in the sorghum. The following letter addressed to the 
Under Secretary for Agriculture by Mr. Henry Tryon, Entomologist and 
Vegetable Pathologist to the Department, will, we think, set at rest any doubt 
as to the existence of a virulent poison in young sorghum plants, and it will 
further serve the purpose of allaying the fears of some who hitherto have not 
ventured to feed their stock even with matured sorghum :— 
Brisbane, 13th August, 1902. 
Srr,—Having regard to the fact that sorghum under some circumstances has 
roved poisonous to stock (a matter that has already engaged the attention of the 
epartment), it would appear that a recent discovery on the part of the Scientific 
Department of the Imperial Institute, that the plant in question during a certain 
period of its growth naturally contains prussic acid (hydrocyanic acid), may have some 
significance in connection with the special action alluded to, and especially so should 
it appear that the toxic effects remarked accord with the well-known physiological 
action of this body. Of course,the fact that hydrocyanie acid boils at 80 Fah., and 
that its vapour pressure is less than half an atmosphere at this temperature, wouldin 
the event of its presence in the animal organism in a measure account for its 
rapid absorption on being ingested. 
The discovery to which allusion is made is announced in the June number of 
Agricultural News (the Fortnightly Review of the Imperial Department for the West 
Indies) in the following words :— 
“Some recent research work in the Scientific Department of the Imperial 
Institute would appear to have afforded a solution to the vexed question of why cattle 
are sometimes poisoned by green sorghum (Sorghum vulgare). . . . - It would 
now appear that sorghum . . ._. contains prussic acid. . . . . The poison 
occurs in the young plants, but gradually disappears as the seeds ripen. 38 
(Op. cit. Vol. 1., No. 5, pp. 70, 71.) 
I have the honour to be, &c., 
HENRY TRYON, 
Vegetable Pathologist and Entomologist. 
The Under Secretary, Department of Agriculture. 
Mr. Tryon has since sent the following further communication to the 
Under Secretary for Agriculture on the subject of the poison contained in young 
sorghum :— 
Brisbane, 9th September, 1902. _ 
Srr,—On the 13th August I had the honour to direct attention to a recent 
discovery made by the Scientific Department of the Imperial Institute, that sorghum 
was found to yield prussic acid, and to suggest that it might have some significance 
with reference to the fatality occurring amongst cattle in this State after partaking of 
the plant in question, and that had already engaged the attention of the Department. 
I now tender, for your further information, the highly interesting authentic record 
of the discovery alluded to, extracted from the proceedings of the Royal Society of 
London, published in June of the present year. 
