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than one species must here be active. That however, the number 

 of typical bacteria should be very great, I think doubtful, for the 

 following reasons: The course of the process of putrefaction is quite 

 the same when the material, after infection with soil, is for some 

 moments heated to 90 a 100° C. as when this is not done. Hence 

 it follows that only spore-forming microbes are typical for the 

 process. The experiment shows further that exclusion of air acts 

 favorably on its course, so that all aerobic microbes appear to be 

 indifferent, except in so far as by absorption of oxygen, they favor 

 the development of the properly so-called putrefaction bacteria. 



By these two data the process was so much simplified from a 

 bacteriological point of view, that there appeared some chance of 

 further unravelling it. Though hitherto I have by no means entirely 

 succeeded, I think, nevertheless, that what follows holds good. 



Three species of obligatous anaërobics are in particular concerned 

 with the putrefaction of proteids. In the first place Bacillus septicus, 

 secondly a group of extremely variable forms, related to the tetanus- 

 bacillus, and to which I will give the name of „skatol-bacteria", 

 and thirdly, an immobile, well-characterised species, called by me 

 B. pseudopulcher . For separating these different species, I used a 

 culture gelatine of the following composition : Destilled water, 10 pCt. 

 gelatine, 3 pCt. pepton siccum, 0,05 pCt. dinatrium phosphate, 0,05 pCt. 

 magnesium sulphate, using at the same time yeast or a blastomycete 

 for withdrawing the oxygen. When put into adeep experimeut-tube, 

 the anaërobics develop even with free entrance of air. 



B. septicus Pasteur, is, according to my experience, one of the 

 most spread species of bacteria, to be found wherever animal Bub- 

 stances are tainting, and very common in dust and in the soil. 

 It is an easily recognisable and well defined species. A virulent 

 form of it goes in the German literature by the name of -Ö. oe(/ew«^*s 

 malifjni^). Material of the latter, occurring in the laboratoria, 

 I compared, also with a view to their relation to oxygen, with cultures 

 of B. septicus, repeatedly isolated by me from putrefying albumen 

 solutions, or fibrine, infected with garden-soil, but I could discover 

 no difference. 



The skatol-bacteria are to be known by the globular spores 

 which are found in proteine putrefactions, in the swollen ends of 

 thin, commonly long staves. One of the forms isolated retained 



1) A bactery, accepted by the medical men cas a particular species, B. Chauveam (of 

 the French) or B. emphy-sniitulos (of the Germans) is, in my opinion, only a variety of it. 



9* 



