SCIENTIFIC RESEARCH IN PRACTICE. 



261 



In order to be able to send to a distance the selected pure 

 cultures in a liquid condition, special forms of flasks were de- 

 vised by HANSEN (Fig. 82) and by the author (Fig. 83). The 

 yeast can be sent to great distances in these flasks, and there 

 is no difficulty in safely transferring it from the flask to the 

 cylinder of the propagating apparatus. 



FIG. 82. 



FIG. 83. 



In sending small quantities of pure cultures, in such a manner 

 that they may be safely and readily employed for further culti- 

 vation, the small Hansen flasks are employed. They are 

 connected, in the flame, with the Pasteur flask in which the 

 pure culture has developed. A trace of the yeast is transferred 

 to the cotton-wool, and the flask is again closed in the flame 

 with the asbestos stopper, which is then coated over with 

 sealing-wax. When the culture is to be used, the flask is 



such appliances useful are now attained for the first time through the intro- 

 duction of pure yeast, and open coolers will therefore gradually disappear in 

 the future. 



