1804 



Journal of Applied Microscopy 



Fig. 43 



a test tube containing sterile water. By letting 

 the reservoir cool, a little of the sterile water is 

 sucked up into it. Now 'draw the capillary tube 

 several times through the flame and invert it in 

 a test tube containing the inoculated medium. 

 The end of the capillary tube should be near 

 but should not touch the surface of the medium. 

 Heat the capillary tube and its reservoir, causing 

 the enclosed water to boil, and when most of the 

 water has escaped from it in form of vapor, im- 

 merse the open end of the capillary tube in the ' 

 medium in the test tube. Upon cooling a va- 

 cuum is formed in the capillary tube and the in- 

 oculated medium is drawn up and fills the entire 

 capillary tube and the reservoir. Now remove 

 the test tube and seal the capillary tube at its 

 curve in the flame. For inoculation break the seal, introduce a fine capillary 

 tube charged with inoculating material, and then seal the tube in the flame. 



Van Semis (1890) uses a glass tube about 1 m. in length and 6 mm. in diam- 

 eter (Fig. 44). End (a) is drawn out into a narrow opening and wrapped up in 

 cotton ; end (b) is plugged with cotton. 



Method. — Pour into a sterile test tube about 

 20 c. c. of liquified, sterile agar or gelatin and 

 inoculate it. Remove the cotton from end (a) 

 of the glass tube and immerse end (a) in the 

 inoculated medium by pushing it through the 

 cotton plug into the test tube. While the 

 U-shape is being turned upward apply suc- 

 tion at end (b) till the medium reaches the curved part. Then turn the latter 

 down, the liquid will now fill the rest of the tube by itself. Seal end (a) in the 

 flame; the. cotton plug at (b) prevents contamination. 



For reaching the isolated colonies proceed as follows : Mark the 

 place, where a well isolated colony is located, with concentrated 

 H 2 SO 4 by means of a glass rod. Wash off with sterile water, scratch 

 with file, and break the glass tube. The colony is now ready for 

 examination and sub-plantation. 



Schmidt (1895) uses a test tube into which a monoperforated rub- 

 ber stopper is well fitted ; the perforation carries a glass tube reaching 

 to the lower surface of the rubber stopper. The glass tube extends 

 upward about 16 cm. and is then bent into a U-shape as shown in 

 Fig. 45. 



Method. — Fill the sterile test tube with bouillon up to 5 mm. below 

 the upper edge of the tube, carefully insert the rubber stopper carry- 

 ing the glass tube so that the air escapes through the latter. The 

 stopper is pushed down until the medium reaches the upper end of 

 Fig. 45. the glass tube. If possible prevent the flowing-over into the turned 



Fig. 44. 



(^ 



