188 



AZOA. 



Several trials of azoa for the destruction of rats have come under 

 the observation of members of the Biological Survey. Experiments 

 made in the building occupied by the Interstate Commerce Com- 

 mission were at first promising, but from a second invoice of the 

 virus no results were obtained. In the buildings of the National 

 Zoological Park 72 bottles of azoa were used, but the results were 

 for the most part negative. In a store in south Washington where 

 this preparation had been used the stench of dead rats was very 

 strong, showing a measure of success. 



DANYSZ BACILLUS. 



Some three years ago the Biological Survey, assisted by the Bureau 

 of Animal Industry, tested the efficiency of Danysz virus. In the 

 laboratory from 10 to 50 per cent of rats fed on the virus died. In 

 the field, however, results obtained were unsatisfactory. Only 1 dead 

 rat was found from which the bacillus was recovered. Experiments 

 with field mice gave better results. All the mice fed in confinement 

 died, and field experiments resulted in many dead mice from which 

 the bacillus was recovered. 



EXPERIMENTS DURING THE SAN FRANCISCO PLAGUE OUTBREAK." 



Several proprietary biological products sold as rat exterminators 

 were made the subject of seven experiments on wild San Francisco 

 rats, for the purpose of ascertaining whether they were efficient 

 for the purpose for which they were sold. Seventy-six rats were 

 used in these experiments. About 10 per cent died within a month 

 and there was considerable doubt as to whether all of the deaths 

 that occurred were due to the agent used. 



The following is a brief statement of the work done with these 

 agents. In each case the rats used were wild Mus norvegicus, caught 

 in San Francisco. 



RATIN NO. 1. 



Made by the Bakteriologik Laboratorium, Copenhagen, marked: 

 " Effective two months from April 28, 1908." The preparation 

 comes ready for use in the form of a moist, mealy mass. On May 28, 

 about 6 ounces of the material was fed to 12 rats. They all remained 

 well until thirty days after feeding them when the experiment was 

 regarded as terminated. 



a These experiments were made by Passed Asst. Surg. G. W. McCoy, United States 

 Public Health and Marine-Hospital Service, in 1907-8 during the plague campaign 

 in San Francisco and here published for the first time. 



