264 



MICROBES, FERMENTS, AND MOULDS. 



.liquid to be examined in Ranvier's moist chamber, 

 consisting of a glass holder, with a circular groove and 

 a flat space in the centre. On the top is a cover-glass, 



Fig. 103. Different forms of culture flasks employed by Pasteur (from Duclaux). 



which is bordered with paraffin or vaseline, in order to 

 seal it. The groove contains air and a little liquid. 



