METHODS USED IN CULTIVATION OF BACTERIA 189 



precautions that the hydrogen is not allowed to enter too fast, or 

 else explosion may follow, and it is best to make some arrange- 

 ment like that used in our laboratory by Dr. Teague where the 

 hydrogen is first let into a glass chamber over water, and allowed to flow 

 in very gradually by graded pressure. The main thing is to so work the 

 apparatus that a very slow jet of hydrogen is made to flow in close to the 

 palla-dmized asbestos, while this is still hot. A small film of water will 

 begin to form on the sides of the tube, and this is continued until a negative 

 pressure has distinctly developed in the jar. Judgment concerning the 

 amount of hydrogen that should be . let in can be attained with practice. 

 Closure of the jar may be then made more firm with paraffin or any of 

 the other ordinary methods of making such jars air tight. Plastocene in 

 sufficient amounts has usually served our purpose. 



We do not illustrate this method because illustrations rarely help an 

 experienced bacteriologist to any great degree, and it is best to see the 

 apparatus work in some laboratory where it is in use. Many modifications 

 are possible, but the principle is easy to apply in a great many different 

 ways. 



By this method it is possible to decolorize methylene blue tubes put into 

 the jars, completely over night, and we believe that this method properly 

 applied gives a practically perfect anaerobiosis. 



The Use of Fresh Sterile Tissues as an Aid to Anaerobic Cul- 

 tivation. The addition of small pieces of fresh sterile tissue (rabbit 

 or guinea-pig) to culture tubes, either solid or fluid, greatly favors 

 the growth of anaerobic bacteria. By such a method anaerobes can 

 be made to develop even when other precautions for the establish- 

 ment of anaerobiosis are imperfectly observed. This was noticed 

 first by Theobald Smith and by Tarozzi and has become an extremely 

 useful reenforcement to other methods. It has been utilized most 

 extensively by Noguchi of recent years in his technique for the 

 cultivation of various treponemata. The simplest way to apply 

 this method is to place a piece of freshly excised rabbit kidney, 

 testicle, or spleen into the bottom of a high test tube (20 cm.) and 

 then pouring over it the culture fluid. Kidney or other tissues are 

 more suitable for this purpose than liver tissue since the latter is 

 not easily obtained in a sterile condition, bacteria often getting into 

 it during life through the portal circulation. The action of the 

 tissues depends upon its great reducing power. 



PARTIAL OXYGEN TENSION FOR THE GROWTH OF BACTERIA. In 1916 

 Wherry and Oliver 12 found that partial anaerobiosis was favorable 



12 Wherry and Oliver, Lancet-Clinic, 115, 1916, 306. 



