472 



BACTERIOLOGICAL ANALYSES 



On reaching the spot whence the samples are to be 

 taken, the coverings of the scoop are removed, and the 

 asbestos cloth employed to brush away loose stones 

 and debris from the selected area. The surface soil 

 is then broken up with the point of the scoop, scraped 

 up and collected in the body of the scoop, and trans- 

 ferred to the sterile capsule for transmission. 



FIG. 218. Fraenkel's borer. 



(b) For deep samples collected at various distances 

 from the surface, an experimental trench may be cut 

 to the required depth and samples collected at the 

 required points on the face of the section. It is, how- 

 ever, preferable to utilise some form of borer, such 

 as that designed by Fraenkel (Fig. 218). 



Fraenkel's Earth Borer. This instrument consists 

 of a stout hard-steel rod, 150 cm. long, marked in centi- 



