1018 RECOED OF CURRENT RESEARCHETS RELATING TO 



gress, but M. Toussaint informs Professor Lister tliat he has already 

 ascertained the existence of immunity against anthrax for 3^ months 

 in both sheep and dogs treated in this way.* 



Identity of Bacillus anthracis and Hay-Bacillus, t — This has 

 been investigated by Dr. H. Buchner of Munich, of whose observa- 

 tions Professor Lister gives the following account : — 



"It is well known that the Bacillus anthracis is morphologically 

 identical with an organism frequently met with in infusion of hay, 

 which may be termed hay-bacillus. Such being the case, it occurred 

 to Dr. Buchner that they might be merely one and the same organism 

 modified by circumstances. For my own part, I am quite prepared 

 to hear of such modifying influence being exerted upon bacteria, 

 having made the observation several years ago that, when the Bacterium 

 lactis had been cultivated for some time in unboiled urine, it proved 

 but a feeble lactic ferment when introduced again into milk. Its power 

 of producing the lactic fermentation had been impaired by residence 

 in the new medium. In the case before us, indeed, the physiological 

 difference between the two organisms seems, at first sight, so great, 

 as to forbid the idea of anything other than a specific difference. The 

 Bacillus antliracis refuses to grow in hay-infusion in which the hay- 

 bacillus thrives with the utmost luxuriance ; and conversely, the hay- 

 bacillus is utterly incapable of growing in the blood of a living 

 animal, whether introduced in small or in large quantities. The hay- 

 bacillus is remarkable for its power of resistance to high temperatures, 

 which is not the case with the Bacillus avthracis. The latter is 

 destroyed by a very slight acidity of the liquid of cultivation, or by 

 any considerable degree of alkalinity, whereas the former survives 

 under such conditions. Both will grow in diluted extract of meat, 

 but their mode of growth difiers greatly. The hay-bacillus multi- 

 plies rapidly, and forms a dry and wrinkled skin upon the surface, 

 while the Bacillus anthracis produces a delicate cloud at the bottom of 

 the vessel, increasing slowly. 



Nothing daunted by these apparently essential differences. Dr. 

 Buchner has laboured with indomitable perseverance, by means of 

 experiments carried on in Professor Niigeli's laboratory, to solve 

 the double problem of changing the Bacillus anthracis into hay-bacillus, 

 and the converse. Having devised an ingenious apparatus by which 

 a large reservoir of pure cultivating liquid was placed in communica- 

 tion with a cultivating vessel, so that any cultivation could be drawn 

 off by simply turning a stop-cock, and further cultivating liquid 

 supplied to the organisms remaining in the vessel by a mere inclina- 

 tion of the api^aratus, Buchner proceeded to cultivate the isolated 

 Bacillus anthracis in extract of meat for several hundred successive 

 generations. As an early result of these experiments, he found that 

 the bacillus lost its power of producing disease in an animal inocu- 

 lated with it. Up to this point he is confirmed by Dr. Greenfield,^ 



* Cf. 'Brit. Med. Journ..' loc. cit. 



t SB. k. Bay. Akad. Wiss.,' 1880, pp. 3G8-413, and Prof. Lister's Address, 

 loc. cit. 



% See this Journal, ante, p. 83S. 



