7*4 
journal of Agricultural Research 
Vol. XI, No. 13 
Inasmuch as the experiments detailed in this paper show that the toxic 
dose for animals is from 6 per cent to 10 per cent of their weight, symp¬ 
toms would hardly be expected from the small quantity which Crawford 
administered to himself, even if man were vastly more susceptible than 
the lower animals. 
Apparently experimenters were so interested in discovering the cause 
of milk sickness that the fact was overlooked that, whether milk sickness 
were produced by E, urticaefolium or not, actual proof had been made 
repeatedly of the poisonous character of the plant. The experiments 
of this paper have confirmed the former work and given definite infor¬ 
mation in regard to symptoms and dosage. 1 
SUMMARY 
(1) Eupaiorium urticaefolium has for many years been considered by 
many people as the cause of milk sickness, or trembles, in cattle. 
(2) Experimental work shows conclusively that the plant is toxic, and 
produces a definite line of symptoms bearing a close resemblance to those 
considered characteristic of trembles. 
(3) Probably many, possibly most, cases of trembles in cattle and 
sheep are due to poisoning by E. urticaefolium . 
(4) Under the term “milk sickness,” or “trembles,” are probably 
grouped at least two distinct things: one poisoning by E . urticaefolium 
and the other a bacterial disease. 
LITERATURE CITED 
(1) Barbee, W.J. 
1840. FACTS RELATIVE TO THE ENDEMIC DISEASE CALLED, BY THE PEOPLE OF 
THE WEST, MILK-SICKNESS. In West. Jour. Med. and Surg., v. 1, p. 
178-190. 
(2) Brooks, E. W. 
1914. milk-sickness. In Altamont News, Altamont, Ill., v. 33, no. 44, p. 1, 5. 
(3) Clay, A. J. 
1914. personal and clinical experiences with milk sickness. In Ill. 
Med. Jour., v. 26, no 2, p. 103-108. 
(4) Crawford, A. C. 
1908. THE SUPPOSED RELATIONSHIP OF WHITE SNAKEROOT TO MILK SICKNESS, 
OR “trembles.” In U. S. Dept. Agr. Bur. Plant Indus., Bui. 121, 
p. 5-20, 1 pi. 
(5) Curtis, R. S., and Wolf, F. A. 
1917. eupatorium ageratoides, the cause of trembles. In Jour. Agr. 
Research, v. 9, no. n, p. 397-404, pi. 22-24. Literature cited, p. 404. 
(6) Dewey, J. S. 
1854. [milk sickness.] In Northwest. Med. and Surg. Jour., v. 11 (n. s., v. 3), 
no. 12, p. 541-547. 
1 Since this paper was offered for publication, Curtis and Wolf (5) have published the details of careful 
feeding experiments at the North Carolina Experiment Station with Eupatorium urticaefolium upon 
sheep, by which they produced 13 fatal cases of “trembles.” Had their work been known when this 
paper was prepared, it would have necessitated some slight changes in the introductory part. As, however, 
their results do not conflict in any way with those obtained by the writers, it has seemed best to leave 
the paper in its original form. 
