26 



ANALYSIS AND ADULTERATIONS OP BUTTER. 



of mutton or beef fat witli butter invariably presents this 

 appearance. K a bollow be formed, the top part of the fat 

 must be refused so as to give a level surface upon which to 

 place the bulb. 



Immerse the tube containing the sample in cold water, con- 

 tained in a beaker of the capacity of 1 litre : the top of the 

 fat must be about 1 J inch below the surface of the water. A 

 convenient method of fixing the tube in position is to pass it 

 through a hole drilled in a piece of wood and placed across 

 the top of the beaker ; by this means two sinking points may 

 be taken at the same time. 



Having fixed the tube in an upright position, drop the 

 bulb on to the surface of the fat. The arrangement is now 

 complete, and heat may be applied by means of a Bunsen 

 burner raised so as to just touch the sand-bath. The water 

 should now be stirred at intervals, and the thermometer 

 read off just as the whole of the globular part of the bulb 

 has sunk beneath the fat. 



The following results have been obtained by this method ; 

 they are placed without selection in the order in which they 

 were obtained. 



Sinking Point with Genuine Butters. 



