PART I. GENERAL BACTERIOLOGY. 

 CHAPTER I. 



MORPHOLOGY AND ELEMENTARY TECHNIQUE. 



EXERCISE I. CLEANING GLASSWARE. 



GENERAL DIRECTIONS. All glassware to contain culture media must be thoroughly 

 clean. New glassware should be washed in hot soap-suds (a test-tube brush will be 

 needed for the test-tubes) , rinsed in tap water and then placed for a few minutes in water 

 to which about 1% of hydrochloric acid has been added to remove free alkali frequently 

 present on new glass, and then thoroughly rinsed in tap water. It is then allowed to 

 drain. Test-tubes and flasks are best dried by placing them on a drain board especially 

 prepared, or standing them mouth down in a box with a cloth bottom or on filter paper. 



Glassware containing media (discarded cultures, etc.), is best cleaned by first stand- 

 ing in water for some hours, or by being steamed and pouring out the material while in 

 a liquid condition and then cleaning as above with the exception of the use of the hydro- 

 chloric acid. 



REFERENCES. A. 120; H. 39; K. & D. 81; M. & W. 74; N. 158; P. 223. 



SPECIAL DIRECTIONS. Clean as directed above, all flasks, test-tubes, fermentation 

 tubes and Petri dishes in your possession. 



EXERCISE II. PLUGGING FLASKS AND TUBES. 



GENERAL DIRECTIONS. When the flasks, test-tubes and fermentation tubes are 

 thoroughly dry they are to be plugged with cotton. The cotton for this purpose should 

 be of the best non-absorbent quality, i. e., as free from foreign matter as possible. The 

 plugs should be sufficiently loose to permit the interchange of gases and at the same time 

 tight enough to support the weight of the vessel and its contents, to prevent their being 

 pulled out in handling the vessel. The cotton should be rolled into a cylinder of the 

 proper diameter and long enough to extend into the mouth about 2? cm. (1 in.) and pro- 

 ject sufficiently to protect the lips from dust. The plug should be pushed in straight and 

 not twisted; the surface next to the glass must be perfectly smooth, presenting no 

 creases for the entrance of dust. 



REFERENCES. A. 121; H. 39; M. & W. 74; M. & R. 56; McF.107; P. 223. 

 SPECIAL DIRECTIONS. Plug all test-tubes, flasks and fermentation tubes in your 

 possession. 



EXERCISE III. STERILIZATION OF GLASSWARE. 



GENERAL DIRECTIONS. The glassware thus prepared is ready for sterilization, which 

 process is accomplished in an apparatus called the hot air sterilizer. This is a sheet iron 

 or copper box with a double wall which permits of rapid heating. The apparatus should 



