( 899 ) 



carbon compound (or compounds), from which the energy, wanted 

 for the vital processes, is also derived ^). 



The cultui'c of lliis bacterium on solid media or in nutrient 

 solutions, containing soluble organic substances has not yet succeeded, 

 which may, of course, have been caused by an erroneous choice of 

 these substances. On the other hand, pure cultures on soliil and iu 

 liquid substrata, without soluble carbon compounds, are easy to be made. 



1. CRUDE CULTURES OF BACILLUS OLIGOCARBOPHILUS. 



Bacllhis olujocarbophlliis is obtained by the following accumulation 

 experiment, which, because of the purity of the thereby resulting 

 vegetation, may be called a "perfect accumulation experiment." 



Into a large ERT;ENMEYER-tlask a thin layer is introduced of a 

 nutrient liquid of the same composition as used for the water culture 

 of higher and lower green plants, but w^ith alkaline instead of acid 

 reaction. 



One takes for instance: 



Distilled water 100 



Kaliumnitrate O.Oi to 0.1 



Dinatriumphosphate 0.02 

 "Mineral solution" 1 drop. 



This "mineral solution" contains in one drop: 



8 Mgrms MgSO, . 7 H,0 



0.05 „ MnSO, . 4H,0 



0.05 ,; FeCl, . 3H.,0 



Tf from this liquid nitrogen, phosphor, kalium or magnesium is 

 left out, special experiments have proved, that no, or but an insigni- 

 ficant grow th is obtained. As to the necessity of the likewise added 

 elements sulphur, manganese and iron, there still exists some doubl. 



The inoculation is made with a not too small quantity of garden- 

 soil, the flasks are closed with a cotton plug, or with filter paper, 

 without impeding the entrance of air by diffusion, and the culture is 

 left in the dark at 23—25° 0. After two or three weeks, the fluid, 

 which itself remains perfectly clear, is seen to cover with a thin, 

 white, or feebly rose-coloured, very dry film, difHicult to moisten, 

 and macroscopically resembling a MycoderirutAilm, but consisting of 

 minute bacteria, microscopically often invisible wiliiout staining, and 

 sticking together by a slimy substance. This is Bacillus oliyocarbophilu.s. 



1) We also found another, rarer specie', belonging to the genus Streptothrix 

 CoH>', with corresponding properties-. It will not, liowever, be further discussed here. 



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