176 



TECHNOLOGY OF BACTERIA. 



Fig. 3. 



a, wine-glass ; b, glass cover 

 (watch-glass) ; c, bell-glass, sup- 

 ported by a square glass plate. 



suring the greatest possible security from contam- 

 ination by atmospheric germs. 

 The culture-flasks employed 

 contain from one to four fluid 

 drachms. "They are made 

 from glass-tubing of three or 

 four tenths inch diameter, and 

 those which the writer has 

 used in his numerous experi- 

 ments have all been home- 

 made. It is easier to make 

 new flasks than to clean old ones, and they are 

 thrown away after being once used. Bellows, op- 

 erated by the foot, and a flame of considerable size 

 -gas is preferable will be required by one who 

 proposes to construct these little flasks for himself. 

 After a little practice, they are rapidly made ; but 



as a large number are re- 

 quired, the time and labor 

 expended in their prepara- 

 tion is no slight matter. . . . 

 After blowing a bulb at the 

 extremity of a long glass 

 tube, of the diameter men- 

 tioned, this is provided with 

 a slender neck, drawn out 

 in the flame, and the end of 

 this is hermetically sealed. 



(See Fig. 5.) Thus one little flask alter another 

 is made from the same piece of tubing, until this 

 becomes too short for further use. 



