106 MICROBIOLOGY 



imperils the purity of the culture. If the bulb is sufficiently 

 large this difficulty will not arise. The connecting tube 

 should not be too small, for then the filling and emptying of 

 the closed branch becomes very tedious. Nor should it be 

 too large, otherwise the anaerobic properties of the fluid in 

 the closed branch may be less effective. Lastly, the angle 

 formed by the two branches of the tube must not be too 

 acute, otherwise the tube must be tilted so much during the 

 transference of the fluid from the tube to the closed branch 

 that there is danger of its moistening the plug or even run- 

 ning out of the bulb." 



Method. Heat the fermentation tube containing pep- 

 tonized sterile glucose bouillon in the steam sterilizer, cool, 

 and inoculate it with the culture in question. In case of a 

 pure anaerobic culture the growth will take place in the 

 closed bulb and the line of demarcation between the turbid, 

 teeming liquid of the closed branch and that of the bulb and 

 connecting tube is sharply drawn. 



Baginisky constructed an apparatus that appears to be 

 simple in construction and easy to manipulate. (Fig. 23.) 



Method. Place the inoculated Petri dishes upon the 

 bottom plate of the apparatus. Invert the bell jar and seal 

 the apparatus by screwing the upper and lower plates firmly 

 against the bell jar. Introduce hydrogen at the upper 

 lateral tube, the air will escape through the other. When all 

 the air is driven out, which is determined by the hydrogen 

 tube test, seal first the exit, then the entrance of gas and 

 place the apparatus in the incubator. A very satisfactory- 

 way is to run the hydrogen through continuously until the 

 cultures are grown. 



This apparatus is also well suited for a large number of 

 tube cultures in hydrogen atmosphere. 



Novy 1 has devised very convenient jars for cultivating- 

 bacteria in tubes and plates in an atmosphere of hydrogen. 

 There is a large number of methods and appliances described' 



Novy. Centralb. f. Bakt., Bd. XIV (1893) p. 581. 



