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 3}4 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 w^ent 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. 

 Water 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 likely 

 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. AVhen 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 



