252 



BACTERIOLOGICAL ANALYSIS OF MILK. 



FIG. 37. 



QUANTITATIVE ANALYSIS OF THE 

 BACTERIA IN MILK. 



Glassware. At the outset there should be 

 carefully washed a number of test-tubes, liter 

 flasks, petri dishes (Fig. 40), cubic centimeter 

 pipettes (Fig. 37), a number of small flasks 

 which are marked to hold 99 c.c. (Fig. 38), 

 together with a considerable number of small 

 vials, like homeopathic vials, marked to hold 

 5 c.c. and another lot marked to hold 19 c.c. 

 (Fig. -38). These various pieces of glass 

 plugged with cotton, are placed in a sterilizing 

 oven and heated for about an hour to a tem- 

 perature approximating 180 C. It is well to 

 sterilize a considerable number of them at the 



FIG. 38. 



i c.c.-pipettes in. 

 closed in glass tubes 

 for sterilizing. 



Flasks and vials for quantitative bacteriological analysis. 



