12 



board from locker. After they are dry, wipe the outside of 

 the tubes with a slightly dampened cloth. 



{b) Fermentation tubes. Treat these in the same manner 

 as the test tubes excepting in the use of the brush which 

 must be omitted. 



(c) Flasks. Wash the flasks thoroughly with soap and 

 water. Then fill them with the cleaning mixture and allow 

 it to act for at least lo minutes after which it can be poured 

 back. Rinse the flasks thoroughly in the same manner as 

 the test tubes and drain them. When dry the outside should 

 be wiped with a damp cloth. 



{d) Petri dishes and reagent bottles. Thoroughly wash 

 the Petri dishes and reagent bottles in hot soap suds after 

 which rinse them separately in hot water. Wipe the Petri 

 dishes dry with a cloth and drain the bottles. The clean- 

 ing mixture need not be u.sed. 



(f) Slides and cover-glasses. Drop the cover-glasses 

 singly into a glass jar containing cleaning mixture and al- 

 low them to remain there for 24 hours or longer. Pour off 

 the cleaning mixture and rinse the cover-gla.sses until all of 

 the color disappears, then cover them with alcohol until 

 needed when they can be wiped with a soft linen cloth 

 or with lens paper. Treat the slides in the same manner as 

 the cover-glasses. They can be wiped directly out of the 

 rinsing water. The slides can be cleaned satisfactorily by 

 washing them in a strong, hot soap suds, rinse in water and 

 wipe. 



(/) Cleaning used culture apparatus. Place the tubes, 

 flasks, or Petri dishes containing old cultures in a water 

 bath, cover them with water to which add a little sal soda 

 (about an ounce to the gallon of water) and boil for 20 

 minutes. Pour off the water and empty the tubes after 

 which again boil them for 5 minutes in clean soap and water. 

 Then wash and treat with the cleaning mixture the same as 

 the new tubes. 



