VETERINARY SCIENCE AND PRACTICE. 487 



The author concludes that the toxic effect of this plant which is 

 manifested at certain times is not due to a poisonous principle inherent 

 in the plant and is not peculiar to the second growth alone. The 

 problem is, therefore, still unsolved. 



Report on cooperative experiments in the treatment of hog 

 cholera, A. T. Peters, C M. Day, and C. H. Walker {JV^ehrasJca 

 Sta. Rpt. 1899^ j)P- 64.-90). — The authors decided to test the value of 

 inoculations with attenuated virus in the treatment of hog cholera. 

 Twenty pigs weighing from 40 to 60 lbs. each were inoculated with 

 0.2 cc. of unattenuated virus, 2 pigs being inoculated each day. The 

 first inoculation was made when the virus was 3 days old. Of this lot 

 the first pig became sick 16 days after the inoculation, or 4 days after 

 the period of incubation, while the last pig to show signs of hog chol- 

 era was taken sick 22 days after the period of incubation. It is there- 

 fore apparent that the infection was not the result of the artificial 

 inoculation, but of hog-cholera germs present in the pens. Six pigs 

 were inoculated with virus made according to the method of Dr. Bil- 

 lings. Thirty-one days after the first inoculation it was thought safe 

 to inoculate a second time with 0.3 cc. of virus. The second inocula- 

 tion was made July 25 and on August 1 all the pigs refused food. 

 All of these pigs with but one exception ultimately died, and the 

 exposure experiments with this one demonstrated that it had become 

 immune to hog cholera. 



The authors conducted experiments with virus prepared according 

 to the Pasteur method of making blackleg virus. In general the 

 spleen was selected as the organ from which the virus was prepared. 

 May 3, 3 pigs were inoculated with this virus. One pig showed mild 

 S3'mptoms of hog cholera May 23 which continued to the 29th, when 

 recovery apparently took place. May 31 these pigs were fed upon the 

 viscera of a pig that had died of hog cholera. The inoculated pigs did 

 not contract the hog cholera, while the check pigs all died of the disease. 



Experiments were conducted in inoculating pigs with a mixture of 

 antitoxic serum and virulent culture. The injection had no perceptible 

 effect upon the pigs thus treated, and after 42 days they were exposed 

 to hog cholera in a badly infected pen. All the pigs took sick within 

 the period of incubation, thus showing that this method does not 

 increase their resistance to the disease. Experiments with the Lorenz 

 method gave entirel}' negative results. A modification of the Lorenz 

 method was tried in which the pigs were first inoculated with virulent 

 culture and later with a dose of serum. The pigs thus treated did not 

 contract the disease until 28 days after receiving the inoculation. 

 These pigs resisted infection 21 days longer than the pigs treated by 

 the ordinary Lorenz method. 



In experiments conducted for the purpose of determining the value 

 of gradually increasing doses of antitoxic serum in the treatment of 



