40 MICRO-OPtGANISMS IN WATER 



absence of air will then make their appearance in due 

 course. 



The appearance of the tube with its anaerobic colo- 

 nies is shown in the figure ^ (fig. 9). 



It is sufficiently obvious how the above arrangement 

 can be used for studying the efiect of different gases on 

 micro-organisms, whilst a simple modification of the 



3-; 



Fig. 9. — C. Feankel's Anaeeobic Tube-culture. 



a, a, glass tube through which hydrogen or other gas is passed ; b, ezit-tube for gas ; 

 c, india-rubber stopper, coated externally with paraffiu. 



ordinary method of plate-culture in damp chambers 

 may also be employed for the same purpose.^ 



Instead of using hydrogen to displace air from a 

 culture material, to be employed for the growth of an 

 anaerobic organism, the removal of the oxygen may be 

 effected by means of bacterial life itself, as devised by 

 Eoux, Salomonsen, and Buchner. For this purpose a 

 small culture-tube is fitted in the ordinary way, steri- 



^ l^Vankel, Centralhl.f. BaUerioJorjic, iii. (1888) 735, 763. 



2 Percy Frankland, * On the Influence of Carbonic Anhydride and 

 other Gases on the Development of Micro-organisms,' Proc.Boy. Soc, xlv. 

 292 ; Frankel, Zeitsclu f. Hygiene, v. (1888) 832. 



