The Bulletin 
17 
Moseley’s account, beyond doubt, contains the best experimental evi- 
■dence which had been presented up to that time on the poisonous prop¬ 
erties of this weed. His results were not entirely convincing, however, 
since Crawford (1908), in criticising them, states: “It cannot be said 
that Moseley has even proved Eupatorium urticaefolium to be a poison¬ 
ous plant, much less the cause of “trembles.” Beach (1883) had pre¬ 
viously recorded the observation that cattle frequently eat this weed 
without any apparent ill effects. 
The most extensive recent studies, except those published in a pre¬ 
liminary report from this Station (1917), bearing on the toxicity of 
white snakeroot are those of Crawford (1908), which were undertaken 
because of an outbreak of trembles resulting in the death of about 50 
head of cattle near Minooka, Ill. Patches of white snakeroot which 
had been browsed were found in pastures where the animals had con¬ 
tracted the disease. Some of these weeds were collected and dried, while 
others were preserved in water to which a small quantity of chloroform 
had been added. Aqueous extracts were then prepared and fed or in¬ 
jected subcutaneously into rabbits, cats, and dogs 1STo cases of trembles 
developed in these animals and Crawford became so convinced of the 
innocuous nature of the plant that he took without ill effect a water 
•extract from 400 grams of fresh Eupatorium urticaefolium. These 
results with aqueous extracts are in accord with those secured by the 
present writers, and which are discussed later in this report. 
Crawford furthermore reports that he fed 58 grams (about one-eighth 
pound) of fresh plant to a lamb weighing 25 kilograms (about 55 
pounds) with the production merely of some diarrheal symptoms. In 
criticising this experiment, Moseley (1909) says that this quantity 
would probably not be fatal to a full grown rabbit. In his summary of 
these experiments, Crawford states “It. cannot be said that it has been 
proved that milksickness is due to any constituent of Eupatorium urti- 
csefolium.” 
The preliminary account referred to above contains the results of 
feeding white snakeroot to sheep during the season of 1916. Since the 
present season’s work has been in part a confirmation of that of 1916, 
it is deemed best to combine all of the data bearing on any phase of 
the problem. These data will, therefore, appropriately appear later 
in this report. 
Distribution and Description of White Snakeroot. 
White snakeroot is a member of the composite family and belongs 
lo a genus which is represented in the southern United States by about 
