FLASKS. 



39 



development is required a drop of the yeast is transferred 



to a Pasteur flask containing wort. The small bent open 



tube on the right has its 



outer extremity packed with 



cotton-wool, to filter incoming 



air. The wide tube on the left, 



which is closed with an asbestos 



stopper, has its lowest bend on 



a level with the bottom of the 



flask. If this tube is connected 



with the side tube of a Pasteur 



flask in the flame, and then 



suction applied to the bent 



tube of the flask, a minute 



part of the yeast lying on the 



bottom of the small flask will 



be sucked into the Pasteur 



flask, without disturbing the 



' Fig. 10 -Carlsberg flask Old model. 



remainder of the yeast deposit. 



If it is necessary frequently to remove a small portion of a 



culture, this process may be recommended. 



Fig. 11. Carlaberg flask Nt-w 



Connection between the flask and the bent tube. 



For the development of very large cultures the Carlsberg 

 vessels (Figs. 10 and 11) are employed. They have a capacity 



