144 LABORATORY GUIDE IN BACTERIOLOGY 



VVhipple, The Microscopy of Drinking Water, New York f 



John Wiley & Sons, 1914. 



Jackson, Biological Studies by the Pupils of W. T. Sedgwick, 

 1906, p. 292. 



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



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

 don, 1911. 



Apparatus needed in addition to the list given on 



IX 5- 



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 125 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 agar 50 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. 



