: ' ; LABORATORY GUIDE IN BACTERIOLOGY 



i retort stand with three rings. 



i thermometer in case. 



i box matches. 



40 grams pepton. 



1 20 grams gelatin. 



50 grams agar. 



6 sheets filter paper. 



50 glass slides. 



1 camel's-hair brush. 

 50 cover glasses. 



2 towels. 



i tube brush. 



50 labels. 



i box for slides. 



3 hollow-ground slides. 

 i glass pencil. 



1 pair forceps. 



2 pairs cover-slip forceps. 



SECTION 3 

 PREPARATION AND CLEANING OF GLASSWARE 



Culture tubes, flasks, fermentation tubes, and petr 

 dishes must be free from organic matter, acids, anu 

 alkalis. They should be cleaned as follows: 



1. Immerse them in a vessel containing soapsuds or 

 soap powder, boil 10 to 15 minutes, then clean them 

 with a tube brush. Or immerse them for an hour in a 

 solution of potassium bichromate and sulphuric acid: 



Potassium bichromate ................ 60 parts 



Water .............................. 300 parts 



Concentrated sulphuric acid ........... 460 parts 



The sulphuric acid should be added slowly with con- 

 stant stirring. 



2. Rinse in tap water. 



