3i6 



few sporcs, as wcll of tlic butyrir ferment as nf aerobics, some aerobic bactery, or a 

 blastomycete must be purposely added for the absoriition of the oxygen. 



In this way a culture is obtained containing only the »oxygenform« of butyric 

 ferment, i. e. only mobile staves and no clostridia. With them a figure of respiration 

 may be produced consisting of a single fine line of quickly moving little staves, situ- 

 ated at some distance from the edge of the cover-glass and the meniscus of the pre- 

 paration, which places the microaërophily of this ferment bevond all doubt. 



If to the fermenting mass pure calcium carbonate is added, by which the acid is 

 neutralised, the growth of the bacteria becoines much stronger, and the staves give 

 place to clostridia rich in granulose, and which at length produce spores. Although 

 the opaqueness caused by the chalk, spoils in some degree the purity of the figures of 

 respiration, yet the experiment succeeds well enough, and leads to the same result, 

 i. e. proves that the clostridia of the butyric ferment are microaërophilous in the same 

 way as the oxygenform. With boiled milk^), in which a spontaneous butyric fermen- 

 tation had originated, the above observations could equally be made. That the same 

 may be said with regard to the butylic ferment (Granulobacter butylicum) formerly 

 described by me''), I need hardly add here, as it was the continued study of this very 

 ferment, which rendered the here described relations clearer to me. 



Ana'érobics of putrefaclion of proteids. The most striking instances of obliga- 

 tous anaërobics are met with in the putrefaction of pepton, or, generally speaking, of 

 proteïne substances. If one wishes to isolate the microbes concerned, efticacious mea- 

 sures must be taken for the exclusion of oxygen, as the quantity of air which these 

 ferments admit, without their growth being impaired, is certainly much smaller than 

 with the butyric and butylic ferments. Hence here in particular it was of importance 

 to study their relation to oxygen. 



Before entering upon my immediate subject, I think it necessary to say something 

 about the different species concerned in the process of putrefaction, the literature on 

 this subject being quite unsatisfactory. 



Bacillus putriücus coli Bienstock ") is an anaërobic, found back by nobody, so 

 that it cannot be typical for the putrefaction of proteids. Besides, an exact micro- 

 scopic examination shows that more 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 foUows 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 



') Milk, boiled in a not too undeep flask, wil! somctimcs get into butyric fcrment- 

 ation, even with frce entrance of air, without the prescnce of aerobics. 



-) Archives Néerlandaises, T. 29, pg. i. .As this ferment produces much more pro- 

 pylicalkohol than butylicalkohol it would liavc been better to call it Granulobacter 

 propyliciim. 



') Zeitschrift für kHnische Medicin, lid. 8, pag. I, 1884. 



