SCIENTIFIC RESEARCH IN PRACTICE. 



259 



details the reader is referred to the exact description in 

 HANSEN'S work. 



A modification of the propagating apparatus has been de- 

 vised by BERGH and JOERGENSEN (Fig. 81). The filtered air 



FIG. 81. Yeast-propagating apparatus devised by BERGH and JOERGENSEN. 



passes through the three-way cocks at A, B, and C, into the 

 two cylinders A and B. The upper cylinder holds about 50 

 litres, and the lower cylinder 160 litres. A is provided with 

 a stirrer (E}, a tube (a) for introducing the yeast and with- 

 drawing samples. The bent tube F is for the exit of the 

 carbon dioxide. The tube G P connects the two cylinders, and 

 the connection can be made or broken by means of the cock Cf. 

 H is the outlet for the water used in cleaning A. 



