DISEASES OF CATTLE 255 



Most of these latter methods depend on the employment of attenuated 

 tubercle bacilli, but the vaccines employed by Arloing are not com- 

 posed of bacilli modified specially in any case either by heat or anti- 

 septics or by a passage through the organisms of cold-blooded or other 

 animals. On the contrary, his vaccine contains living bacilli of bo- 

 vine origin profoundly modified in their tubercle-producing power by 

 a long series of cultures in the depth of glycerinated bouillon. The 

 modifications which they have taken on are henceforth fixed and of 

 such a kind that these bacilli form races indefinitely transmissible. 

 These races, comparable to the antianthrax vaccines of Pasteur, can 

 no longer cause tuberculosis of the viscera and glands under the con- 

 ditions where they are recommended to be employed. Being without 

 danger to the monkey, Arloing considers that they are also without 

 danger to man. By their characters these vaccines are somewhat sim- 

 ilar to the virulent vaccines of Prof. Klimmer, of Dresden. They can 

 not cause any fatal infection in the ox, which is contrary to the bovo- 

 vaccine of Von Behring and the tauruman of Koch and Schiitz, since 

 these may be fatal to from 7 to 8 out of every 1,000 subjects 

 vaccinated. 



Arloing concludes by stating that the phase of experimental re- 

 searches in tuberculosis vaccination is not closed, and it is to be hoped 

 that by perseverance in laboratory studies the methods will be per- 

 fected, and we will know better the conditions which follow and those 

 which guarantee success. But such as they are to-day, it would be 

 negligent not to profit by the results acquired to try and restrain the 

 ravages of bovine tuberculosis by associating vaccination with ordi- 

 nary prophylactic measures, as one does for other contagious maladies. 



As a result of these various papers and the discussions which 

 they elicited, the following resolutions were adopted by the Ninth In- 

 ternational Congress held at The Hague in 1909 : 



1. At the present time there is no vaccination which in itself is 

 sufficient to combat in an efficient manner bovine tuberculosis in 

 heavily infected herds. 



2. In how far it is possible to bring about a more successful issue 

 of the difficult struggle against bovine tuberculosis by a combination 

 of vaccination with prophylactic and hygienic measures must be dem- 

 onstrated by new practical experiments. 



3. The congress urgently requests the Governments to grant the 

 means for extensive experiments to examine the methods of vaccina- 

 tion against bovine tuberculosis under the different conditions of 

 agricultural practice. 



THE BUREAU EXPERIMENTS. 



Probably no methods for the immunization of cattle- against tu- 

 berculosis have been more widely discussed or have given better re- 

 sults than those known as Pearson's and Von Behring's. The two are 

 practically alike, and consist of the intravenous injection of living 

 cultures of human tubercle bacilli of a virulence too low to cause a 

 progressive tuberculosis in cattle. The tubercle bacilli are grown in 

 artificial cultures, and in a very finely subdivided condition, sus- 

 pended in fluid in definitely known quantities, are injected into a 



