March, 1906.] The Cause of Trembles in Cattle. 
481 
afternoon but did not rise as the days went on and, although 
well fed and allowed to stay part of the time with rabbit No. 9, 
nothing availed to bring her temperature up to 102°, until she 
was given milk in which snake-root had soaked. This was on 
the evening of Jan. 11 and the following days. Jan. 12 her 
temperature reached 101.8°; Jan. 13, 102.6°; Jan. 14, 104.3°. 
Further experiments with rabbits have shown that, like cats, 
they may acquire some degree of tolerance of the poison, also 
that one ounce gathered in January is not sufficient to kill a 
large rabbit. One weighing 3J4 pounds ate 28 grams of snake- 
root January 21-27, with a little good food. Twitching was 
noticed January 27-30, during which time she was well fed. 
Then she ate nine grams more of snake-root but survived. 
Another weighing nearly four pounds was made to tremble or 
twitch by injections of a decoction of snake-root January 21, 22 
and 30, and by eating of the leaves and branches 67 grams, 
February 1-5, but survived. 
Sheep. 
No. 11. Saturday morning, Jan. 6, 1906, I went into the 
country and selected from a flock a healthy female lamb of 
about forty pounds weight and brought it home on the electric 
cars. In the afternoon I gathered in the woods 88 ounces of 
white snake-root of which I gave her 8 ounces at 4:45, on the 
next day 34 ounces and the remainder Monday and Tuesday 
morning. She took it more readily than I had expected, in fact, 
after being without other food not very long she ate the snake- 
root leaves quite greedily, but the coarse stems would not eat at 
all, even when cut into rather small pieces and soaked over 
night in water. The total amount consumed was about 29 
ounces. Other food was withheld only until Monday when at 5 
P. M. I gave her about a pint of bran all of which she ate. 
W ater was offered several times every day but only a few ounces 
taken altogether. 
Until Tuesday evening I saw nothing wrong with her what- 
ever though Tuesday noon I noticed that she had not cleaned 
out the box containing the snake-root leaves quite so well as 
before. If she had been watched long at this time quite likelv 
some effect of the poison would have been noticed. I did not 
see her again till after dark. Then having weighed out some 
freshly gathered snake-root to give her I noticed that she stood 
facing away or to the side instead of manifesting eagerness for 
it as heretofore. Then I noticed deep and unnatural breathing, 
an almost spasmodic movement of the sides. After taking a few 
steps, she lay down as if unable to stand. When pushed she 
arose, walked a few steps and sank down again. I went for 
H. H. Lockwood who had seen sheep affected by trembles and 
