STUDY OF JEAST. 



97 



in a 



tight. Set the apparatus aside 

 warm place for a few hours. 



a. What change has taken place in the 



lime-water ? 



b. What kind of gas is produced by the 



growth of yeast? 



io. (Dem.) Pour into another flask some of the 

 yeast mixture which has been working 



FIG. 7. 



for some time. Procure a rubber stop- 

 per with two holes. Through one hole 

 pass the bulb of a chemical thermometer 

 so that it reaches half-way down to the 

 bottom of the flask. Through the other 



