EXAMINATION OF WATER FOR MrCRO-ORGANISJVIS 81 



obtain uniform contact between the sensitised paper 

 and the plate it is advisable to interpose a piece of 



Fig. 14. — Photographic Reproduction of a Gelatine -plate Culture. 



u, the glass plate ; b, the gelatine film ; A, colonies causing liquefaction of the gelatine. 



(After de Giaxa.) 



thick cloth between the paper and the board on which 

 it rests. The plate is further covered with a thin glass 

 bell-jar, in order to protect it from dust and other 

 foreign particles. 



