506 SUMMARY OF CURRENT RESEARCHES RELATING TO 



to rats (M. decumanus), M. J. Danysz made attempts to raise the viru- 

 lence of the microbe for the purpose of obtaining a poison which could 

 be used after the manner of Loeffler's B. typhi murium. He succeeded 

 in increasing the virulence by infecting flasks filled with bouillon with 

 pure cultures. Growth was started at incubation temperature, and then 

 the flasks were kept at ordinary temperature for 4-5 days, by which time 

 the bouillon had cleared up and a sediment deposited. The object of 

 this step was to accustom the microbe to living without air. 



Collodion-sac cultures made from the contents of these flasks were 

 inserted in the abdominal cavity of a rat, from which they were trans- 

 ferred to bouillon, and then to flasks again. Gelose cultures from the 

 flasks were made, and these, steeped in water and soaked in bread, were 

 given to mice to eat. After four or five repetitions of the procedure, 

 the virulence was found to be considerably augmented. Eats were then 

 substituted for mice, and the procedure repeated for about ten times, when 

 the cultures were found to be sufficiently virulent. The bouillon used 

 was made of horse flesh, with 1 per cent, pepton, and a little carbonate 

 of lime to neutralise the acids produced during cultivation. 



Flask cultures, kept from air and light, jtreserve their virulence for 

 several months ; gelose cultures for 1-2 months. 



Records of experiments for ridding sewers, ships, warehouses, and 

 stables of rats are given. Some of these appear to have been success- 

 ful, others not. 



Value of the Agglutination Test as a means of Diagnosis of 

 Bacillus typhosus from Coliform Organisms.*— Prof. W. H. Horrocks 

 remarks that the correct interpretation of the agglutination test may be 

 a matter of considerable difficulty. The experiments given show dis- 

 tinctly that there are at least two important factors which enter into the 

 reaction, namely : — (1) the strength of the serum employed, and (2) the 

 time during which the serum is allowed to act on the microbe ; conse- 

 quently no fixed dilution of typhoid serum can be laid down which 

 will enable B. typhosus to be at once distinguished from coliform organ- 

 isms. It may be said that an organism which fails to agglutinate with 

 typhoid serum is certainly not B. typhosus ; but on the other hand, it 

 does not necessarily follow that an organism is B. typhosus because it is 

 agglutinated by fairly dilute typhoid serum. With our present know- 

 ledge it appears essential to work with a powerful serum, and the sus- 

 pected organism should be tested with serum diluted to the highest 

 degree which has been found capable of agglutinating a true B. typhosus. 



Endocarditis and the Influenza Bacillus.f — Miss M. F. Austin de- 

 scribes three cases of acute heart disease from the endocardium of which 

 minute bacilli were isolated. In shape and staining reaction they re- 

 sembled the bacillus of influenza. Cultures were not obtained, but the 

 vast number of organisms present in the valves showed that they were 

 causally connected with the endocarditis. 



New Bacillus found in Vaccine Pustules.:}: — Prof. K. Nakanishi 

 has found in the vaccine pustules of calves, and in the vaccine lymph 

 of children, a very polymorphic bacterium belonging to the diphtheria 

 group. Five chief polymorphic modifications are described. In size 



* Brit. Med. Journ., 1900, i. pp. 1015-7. 



t Bull. Johns Hopkins Hosp., x. (1899) pp. 194-5. 



\ Centralbl. Bakt. u. Par., 1" Abt., xxvii. (1900) pp. 641-61 (2 pis.). 



