272 GENERAL MICROBIOLOGY 



D. HANDS 



Method. 1. Wash the hands in the ordinary manner, 

 rinse them thoroughly, then wipe with an ordinary towel. 



2. After this has been done, put 500 c.c. of sterile water 

 in a sterile dish, and rub the hands thoroughly with this 

 water. 



3. Plate 1 c.c. of this water in litmus lactose agar. 



4. Again rub the hands, before they have been washed 

 and after working for some time, in 500 c.c. of sterile water 

 placed in a sterile dish. 



6. Plate 1 c.c. of this water in litmus lactose agar. 

 6. Compare the numbers (using 1 c.c. as the unit) and 

 kinds of bacteria in the two plates. 



E. PAILS 



Method. 1. Add to a milk pail washed in the usual 

 manner, 500. c.c. of sterile salt solution, and plate in litmus 

 lactose agar, 1 c.c. of this suspension after it has been 

 moved over the inner surface of the pail. 



2. Repeat by using a milk pail heated in steam for ten 

 minutes, or cleansed with boiling water. 



3. This same process may be repeated using milk bottles, 

 milk cans, etc. 



F. AIR 



Method. 1. Determine qualitatively the microflora 

 of the air of the stable before feeding or bedding or before 

 any disturbing, and after feeding or bedding or after any 

 disturbing, by the following methods : 



2. Pour the liquefied litmus lactose agar into several 

 Petri dishes, and expose the poured plates for different 

 lengths of time. 



3. Expose 10 c.c. of sterile 0.6% salt solution in a deep 

 Petri dish 5 c.c. deep and 9 c.c. in diameter. Try to disin- 



