RELATIONSHIP OF WHITE SNAKEROOT AND MILKSICKNESS. 15 



much enlarged, weighing about twice as much as normal. One can 

 form no positive opinion as to the cause of death. The enlarged kid- 

 neys, taken in connection with the history of convulsions and fluid 

 in the peritoneal cavity, might suggest a nephritis. 



Six ounces (170 grams) of the liver of this animal were fed to 

 a cat. This cat showed merely a few tremors. A second cat also ate 

 6 ounces (170 grains) of the muscles but showed no tremors, and 

 a dog after eating 4 ounces ( 103.4 grams) of the liver showed no symp- 

 toms save some dullness, but after feeding on the heart and spleen 

 some tremors were noticed. None of these animals died. 



These experiments, taken in the light of Graffs work, indicate that 

 the sheep had not the disease commonly known as ,; trembles." 



Moseley explains the lack of results in some of his experiments by 

 the existence of a hypothetical immunity, but cases of milksickness 

 are known not to possess immunity — in fact, one attack rather pre- 

 disposes to another, so that it can not be said that Moseley has even 

 proved Eupatorium ageratoides to be a poisonous plant, much less the 

 cause of " trembles." 



RECENT INVESTIGATIONS. 



In the month of August, 1906, a rather serious outbreak of milk- 

 sickness, or as it is frequently called in the case of stock " trembles," 

 occurred in the vicinity of Minooka, 111., resulting in the death of 

 about 50 head of cattle. The office of Poisonous-Plant Investiga- 

 tions was asked to undertake an investigation into the cause of the 

 trouble. In view of the fact that only plants as popularly understood 

 are the subject of investigation by this office, only plants were studied. 

 The widespread and popular belief that the eating of the white snake- 

 root {Eupatorium ageratoides) , illustrated in Plate I, is the cause of 

 the trouble seemed to direct the principal efforts of the investigations 

 toward that common plant. It was found in considerable quantities 

 in pastures in which the animals were supposed to have contracted the 

 disease, and in a number of patches the plants had been browsed, 

 presumably by the stock. Material from these patches, both dried 

 and in chloroform water, was preserved for study. 



EFFECT OF WHITE SNAKEROOT ON RABBITS. 

 EXTRACTS FROM DRY PLANT. 



To prepare the material for use, 200 grams of the dry herb Avere 

 extracted with cold water and the extract evaporated to the desired 

 concentration in vacuo at about 55° C. When such an extract was fed 

 to a rabbit weighing 4 pounds 2 ounces (1,871 grams) no symptoms 

 were noted, either immediately or on the following day. Two clays 

 after the first dose a like quantity was again administered and no 

 32893— Bui. 121—08 2 



