ZYGADENUS, OR 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 

 cither 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, caffein 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, 



