ZYGADENUS, OK DEATH CAMAS. 37 
EFFECT OF REPEATED FEEDING IN PRODUCING IMMUNITY OR IN- 
CREASED SUSCEPTIBILITY. 
During the course of the experimental work at Greycliff a number 
of sheep were treated with Zygadenus several times during the 
same season. It was important to decide whether a sheep after 
having been poisoned once was more or less likely to be affected a 
second time. A careful analysis of the results showed that no effect 
either of immunity or of increased susceptibility was produced. 
The fact that an animal had suffered from poisoning once neither 
lessened the effect of another dose, nor, on the other hand, was the 
sheep any more likely to suffer from a second experience. 
REMEDIES. 
Because of the heavy losses of sheep from Zygadenus poisoning 
it was deemed important to investigate thoroughly the possibility 
of finding some remedial measures to reduce the number of deaths. 
To this end a large number of experiments were made, as can be seen 
by an examination of the table giving the summarized account of the 
work. 
It has been shown by Hunt that the poisonous principle of Zyga- 
denus is excreted in the urine, and this has been verified by the 
authors in the cases of some of the sheep used in the Greycliff experi- 
ments. Hunt concluded that the logical remedy is some diuretic 
which will insure excretion rapid enough to prevent serious effects 
from the poisoning, and his experiments seem to substantiate this 
position. He also advised the use of permanganate of potash 
administered per os to destroy the alkaloid in the stomach. 
The experimental work on remedies in 1912 was based upon these 
conclusions of Hunt. Later, a number of remedies were used in the 
hope that some method might be found sufficiently simple to be used 
under range conditions. This work was carried on for three summers 
in order to get the average of a considerable number of cases, and 
a brief statement of the results of the more important experiments 
follows. 
CAFFEIN AND DIURETIN. 
The conclusions reached by Hunt led to a series of experiments 
with caffein. In 1912, caff em sodiobenzoate was administered to 
five animals subcutaneously; in two of these cases potassium perman- 
ganate was also used, and in one tannic acid. It was evident that 
by the use of this drug the excretion of urine was increased, but the 
observers could not see that any marked improvement followed in 
the condition of the animals. In the summer of 1913, diuretin and 
caffein citrate were given per os in four cases, of which one died and 
three recovered. In these cases, as in those of the preceding year, 
