74 A Neiv Dairy Industry. 



ing the greatest facility to be turned inside out for 

 the purpose of cleansing. The only disadvantage of 

 such a stopper as compared with the porcelain and 

 wire arrangement is that it is more liable to get lost 

 or mislaid. 



After having taken every precaution to make the 

 process of sterilizing effective, we naturally evince a 

 desire of acquiring a knowledge of the degree in 

 which we have been successful, and this desire be- 

 comes an absolute necessity when we turn to manu- 

 facturing milk into food for infants. 



As by sterilizing, we have given the milk good 

 keeping qualities, we may keep the milk stored in a 

 cool place until the investigation which we shall have 

 to institute is concluded, and shall have shown us just 

 how long the milk, which we have sterilized at a cer- 

 tain date, will remain pure and sweet if kept at a tem- 

 perature of 60° F. or below. 



The apparatus which we make use of (termed a 

 thermostat) is an incubator constructed expressly for 

 the purpose of hatching bacteria or breeding certain 

 of their species ; its outward appearance and constuc- 

 tion are shown in cut on opposite page representing 

 a machine built by F. Sartorius, in Gcettingen, Ger- 

 many, where it is extensively used, and has been 

 found entirely reliable. There is a heating chamber 

 in the center with glass pannell-clad door which may 

 be darkened by prefixing a felt pannelling. Bacteria 

 grow more rapidly in the dark. This chamber is 

 completely encased by a water chest, w, the inner snr- 



