f UNIV. OF FL LIB. 
nflpAJMENTS DEPT. 
JEPOSITORY 
A. I. 26 
jjB&fy^fmjjhk^z^ 
United States Department of Agriculture, 
JOHN R. MOHLER, Chief of Bureau.l» . **• 4 • Co $ 
WHITE SNAKEROOT OR RICHWEED (EUPATORIUM URTI- 
CiEFOLIUJVl) AS A STOCK-POISONING VlJ&3£;„0tfl $l 
\\\ C. Dwk.iii Maksh and A. \\. Clawson„o/ //k Pathological Division. 
THE CAUSE OF MILK SICKNESS^ 
Among the suggested causes for the disease popularly known as 
milk sickness, trembles, slows, tires, elc, has been the plant -commonly 
called " white snakeroot " — Eupatorium urti.cn 'folium, or Eupatorium 
ayeratoides of the older literature. Many arguments have been 
advanced both for and against this theory. In later years the possi- 
bility of the connection of this plant with the disease has lessened, 
since Crawford (1908) published his negative pharmacological work, 
and Jordan and Harris in 1909 published their paper on the Bac- 
t< rium lactimoihi. Although there have been authors who clung to 
the white snakeroot origin of the disease, it has been believed rather 
generally that the real cause was not a plant poison but more likely 
a .disease-producing germ. 
Somewhat extended experiments upon this subject have been car- 
ried on by the United States Department of Agriculture, and though 
the general results of the experiments in their relation to the disease 
of milk sickness are not in form for publication, it has been clearly 
demonstrated that Eupatorium urtiaifoVnm must be counted as 
one of the rather important stock-poisoning plants which produce 
serious losses of domestic animals. On this account, although the 
work is incomplete, it seems wise to publish a summary of the results 
so far as they relate to Eupatorium wrUccefMium as a poisonous 
plant, with the hope that some of the losses may be avoided, for it is 
evident that while in many localities this plant is suspected to Be ihe 
cause of milk sickness, its importance as a stock-poisoning plant baa 
received little recognition. 
DESCRIPTION OF THE PLANT. 
Eupatorium urtim folium Reiehard (fig. 1). quoted as E. agera- 
toides L. in the older botanies, is a -lender, erect, perennial herb, 
1 Preliminary paper. 
18029°— IS 
