116 BACTERIOLOGICAL ANALYSIS LESSON 



The latter should be placed in a wide-necked bottle, 

 and this should be exhausted of its air. 



Every time the bottle is opened it must be again 

 exhausted. 



B. EXAMINATION OF SOIL FOR TETANUS AND MALIG- 

 NANT (EDEMA BACILLI. 



Two samples of sterilised black garden earth, artificially 

 impregnated with tetanus and malignant cedema bacilli 

 respectively, are supplied. 



(a) Growth in an exhausted flask. 



(1) Introduce small quantities of each sample into tubes 

 containing liquid grape-sugar gelatine, and gently shake 

 the tubes. 



(2) Make several dilutions in the ordinary manner. 



(3) Prepare roll tubes. 



(4) Place some of these roll tubes in a wide -necked 

 bottle, which must then be exhausted (vide p. 114). 



(5) Proceed exactly as described previously (vide p. 114). 



The tubes must be examined, from day to day, for 

 colonies of tetanus or malignant cedema bacilli. 



If any colonies of tetanus or malignant cedema bacilli 

 appear, start subcultures in grape-sugar gelatine 

 (stab cultures), which must be placed in a flask, 

 the air of which is subsequently exhausted. 



(b) Growth in hydrogen. 



(1) The remaining roll tubes, loosely plugged, should 



