ICE CREAM: BUTTER 457 



6. If apparently M. melitensis, inoculate growth from 

 a nutrose agar culture after three days incubation in- 

 tracranially into the guinea-pig. 



ICE CREAM. 

 Collection of the Sample. 



1. Remove the sample from the drum in the ladle 

 or spoon with which the vendor retails the ice cream, 

 and place it at once in a sterile copper capsule, similar 

 to that employed for earth samples (vide page 471). 



2. Pack for transmission in the ice-box. 



3. On arrival at the laboratory place the copper 

 capsules containing the ice cream in the incubator at 

 20 C. for fifteen minutes that is, until at least some 

 of the ice cream has become liquid. 



Qualitative and Quantitative Examination. Treat 

 the fluid ice cream as milk and conduct the examina- 

 tion in precisely the same manner as described for 

 milk (vide page 443). 



EXAMINATION OF CREAM AND BUTTER. 



Collection of the Sample. Collect, store, and trans- 

 mit samples to the laboratory, precisely as is done in 

 the case of ice cream. 



Quantitative. 



Apparatus Required: 



Sterile test-tube. 



Sterilised spatula. 



Water-bath regulated at 42 C. 



Case of sterile plates. 



Case of sterile graduated pipettes, i c.c. (in hundredths). 



Tubes of gelatine-agar (+ 10 reaction). 



Plate-levelling stand, with its water chamber filled with water 

 at 42 C. 



METHOD. 



i . Transfer a few grammes of the sample to a sterile 

 test-tube by means of the sterilised spatula. 



