189 



DANYSZ VIRUS. 



The Danysz Virus Company (Limited) , of London, furnished a 

 preparation in the form of a culture on a slant of solid medium, said 

 to be gelatine. The tube was marked: "To be used before June 1, 

 1908." The contents of the tube, mixed with bread, according to 

 directions, was fed to 6 rats. On the twenty-first day but 4 rats 

 remaiaed, 2 having died and been devoured by their companions. 

 The 4 that remained were chloroformed, as the cage was needed for 

 other purposes. Post-mortem examination showed them to be 

 entirely normal. 



RATITE. 



Furnished by the Pasteur Vaccine Company, Chicago. This prep- 

 aration is in the form of a culture in a liquid medium, presumably 

 broth. The bottle was dated April 10, 1908, and the label stated 

 that it should be used within twenty days from date of preparation. 

 On April 29, 1908, 9 rats were fed with about 6 ounces of the prepara- 

 tion, mixed according to directions. The rats all remained alive and 

 well, and when chloroformed on June 1, 1908, presented no abnor- 

 mality on post-mortem examination. In another experiment the 

 contents of a bottle of ratite was fed to 6 medium-sized Mus norve- 

 gicus. None of the animals died from the effects of the agent, and 

 when they were killed on the fifty-fifth day after the feeding were 

 found to present no lesions. 



The remaining work was done with rat virus, sometimes called 

 "Mouratus." It is made by the same concern that makes the ratite. 

 The rat virus comes in the form of a culture on a solid medium. 

 The contents of three tubes was fed to 6 rats on May 26, 1908. Three 

 of these rats died within thirty days. Only one was secured for 

 examiaation before it had been mutilated beyond the possibility 

 of making a satisfactory examination. This rat had a large yellow 

 liver and a very large, dark, firm spleen. These appearances were 

 probably due to the agent used and it is not unlikely that these 3 

 rats died from its effect. It will be observed that a very large dose 

 was given. On another occasion four tubes of Mouratus were used 

 for feeding 6 Mus norvegicus. One of the rats died on the fifteenth 

 day, showing at autopsy an enlarged granular spleen and a granular 

 liver. The other rats were alive and well at the end of thirty-four 

 days when the experiment was discontinued. 



Subcultures on broth were made from this preparation on three 

 occasions, always well within the time limit on the label. The cul- 

 tures were incubated in the dark, at room temperature, for forty 

 hours on each occasion. Liberal amounts of the subculture were 

 fed to a total of 31 rats. At the end of thirty days, it was found that 



