/[/[/[ BACTERIOLOGICAL ANALYSES 



contents, secured from shaking by packing with cotton- 

 wool, are sterilised in the hot-air oven (Fig. 26). 

 When collecting a sample, 



1. Remove the cap from the cylinder. 



2. Draw out the cotton- wool. 



3. Lift out the bottle and dipper together. 



4. Receive the milk in the sterile dipper, and pour it 

 directly into the sterile bottle. 



5. Enter the particulars necessary for the identi- 

 fication of the specimen, on the tablet, with a lead 

 pencil, or pen and ink. 



6. Pack the apparatus in the ice-box for transmission 

 to the laboratory in precisely the same manner as an 

 ordinary water sample. 



"Whole" milk may with advantage be collected in 

 the sterile bottle directly since the mouth is sufficiently 

 wide for the milker to direct the stream of milk into it. 



Condensed milk must be diluted with sterile distilled 

 water in accordance with the directions printed upon 

 the label, then treated as ordinary milk. 



Apparatus Required: 



Case of sterile capsules (25 c.c. capacity). 



Case of sterile graduated pipettes, 10 c.c. (in tenths of a cubic 



centimetre). 

 Case of sterile graduated pipettes, i c.c. (in tenths of a cubic 



centimetre) . 



Flask containing 250 c.c. sterile bouillon. 

 Tall cylinder containing 2 per cent, lysol solution. 

 Plate-levelling stand. 

 Case of sterile plates. 

 Tubes nutrient gelatine or gelatine agar. 

 Tubes of wort gelatine. 

 Tubes of nutrient agar. 

 Water-bath regulated at 42 C. 

 Bunsen burner. 

 Grease pencil. 



METHOD. 



i. Arrange four sterile capsules in a row; number 

 them I, II, III, and IV. 



