416 



MICRO-ORGANISMS AND FERMENTATION. 



the receiver, and thence may be passed into either the wort 

 or the fermenting cylinder. In either case the air is sterilised 

 by means of a cotton-wool filter (g, m). The wort cylinder 

 is directly connected with the copper from which the boiling 

 hopped wort is run in ; it is then aerated in the closed cylinder, 

 and is cooled by spraying. 



Fig. 98. Yeast-propagating apparatus devised by Hanseu and Kiilile. A, air-pump; B, air- 

 vessel ; C, fermenting -cylinder ; a, window ; It, b, b, stirrer ; c, c, doubly-bent tube ; d, vessel 

 containing water ; I, outlet cock ; /, /, glass tube connected at e and h with the cylinder, and 

 graduated for the measurement of fixed quantities of liquid ; tj, filter ; i, rubber connection for 

 glass tubes ; j, tube with rubber connection for introducing the pure culture ; k, k, connection 

 with the wort-cylinder D ; m, filter ; n, n, doubly-bent tube ; o, vessel containing water ; p, p t 

 (praying tube ; u, connection with cock * ; t, waste for cooling water. 



The wort is then forced into the fermenting-cylinder, which, 

 like the wort-cylinder, is constructed on the same principle as 

 the ordinary two-necked flask. It is fitted with a doubly-bent 

 tube (c, d), which dips into a vessel containing water ; a vertical 

 glass tube (/, i, /) for measuring the height of the liquid in the 



