and Laboratory Methods. 



1745 



Fig. 15. 



the purpose of sealing the apparatus when exhaustion is 

 complete. 



Hewett (1894) recommends for bouillon cultures the 

 use of an yeast flask of 90 c.c. capacity. The flask is 

 c\psed by a monoperforated, well fitting rubber stopper 

 through which a glass tube passes to the bottom of the flask. 

 The part of the tube extending above the stopper is cotton 

 plugged. A lateral tube projects from the side of the neck 

 as shown in Fig. 15. The lateral tube is also plugged with 

 absorbent cotton. It leads into a cup containing mercury, 

 the latter forming a valve. The surrounding air cannot 

 enter, while the interior air and the gases formed by 

 bacterial activity have free exit. 



Method. — Fill the flask about two-thirds full with glucose bouillon, sterilize, 

 cool and inoculate the medium. Introduce hydrogen through the glass tube in 

 the rubber stopper for one hour, before disconnecting the generator dip the end 

 of the lateral tube into the cup containing mercury, and seal tube (b) above the 

 rubber stopper in the flame. 



Liibinski (1894) constructed two forms of apparatus. One of these resem- 

 bles that of Novy so closely that it need not be described here. The second 

 apparatus is illustrated in Fig. 16. It is closed with a ground glass stopper. 

 Immediately below the neck the cylinder carries at two diametrically opposed 

 places tubes (t) and (t^), ending in glass bulbs. Both bulbs are partly filled with 

 liquid paraffin or vaseline. In order to prevent the liquid in bulb (t) from passing 

 over into the apparatus, bulb (t) is separated from the cylinder by a second bulb. 

 The gas is introduced through bulb (t)^ ; bulb (t) serves as exit for the air. As in 

 Novy's apparatus the entrance of gas and exit of air take place at different heights. 

 The manipulation is very similar to that of Novy. 



Jacobitz (1901) successfully made agar slant cultures in nitrogen atmosphere. 

 He used Fraenkel's tube. Into the boiling hot agar he introduced a current of 

 nitrogen purified by running through concentrated sulphuric acid, through alka- 

 line pyrogallol and through potassium hydroxide. He then lays the tube on an 

 ice tray to slant the agar, continuing the current of nitrogen until the agar is 

 congealed. After inoculating in the usual way more 

 nitrogen is introduced. Finally the entrance and exit 

 gas tubes are sealed hermetically in the flame. 



B. PLATE CULTURES. 

 Kitasato (1889) used a flattened receptacle about 

 •1 cm. thick (see Fig. 17) for the isolation of tetanus. 

 The manipulations of the apparatus resemble those 

 employed in the case of Liborius tubes. The two 

 openings are plugged with cotton and the apparatus 

 is sterilized. Then the surface tube (b) is constricted 

 in the middle. With a well drawn out funnel about 

 Fig. ig. 20 c. c. of the liquified inoculated medium are poured 



