144 LABORATORY GUIDE IN BACTERIOLOGY 



Whipple, The Microscopy of Drinking Water, New York^ 



John Wiley & Sons, 1914. 



Jactson, Biological Sludies by the Pupils o-} W. T. Sedgwick, 

 1906, p. 292. 



Fuller and Johnson, Jour. Exper. Med., 1899, 4, p. 610. 



Don, Chisholm, Modern Methods of Water Purification, Lon- 

 don, 1911. 



Apparatus needed in addition to the list given on 



P- S- 



Two hundred culture tubes. 



Four wire baskets. 



Twenty fermentation tubes. 



Twelve Erlenmeyer flasks, about 150 c.c. each. 



Six wide-mouth glass-stoppered bottles of about 121; c.c, 

 capacity. 



Twenty petri dishes. 



Twenty-five i c.c. pipettes. 



Ten 10 c.c. pipettes. 



SECTION I 



PREPARATION OF CULTURE MEDIA AND OF DILU- 

 TION FLASKS 



Dextrose or lactose agarose tubes. Thirty-five 

 tubes should contain 10 c.c. of agar for plating; the 

 others about 7 c.c. 



Nutrient gelatin — 20 tubes. This gelatin should 

 contain 12 per cent gelatin. This percentage is 

 reduced to 10 per cent after the contents of a tube has 

 been mixed with the litmus solution and the water used 

 for plating if 10 c.c. gelatin are filled into each tube. 



Litmus solution — 20 tubes. 



Lactose bile fermentation tubes — 30. 



