MILK AND DAIRY PRODUCTS PART 



flow slowly on to the acid, so that the two liquids mix as 

 little as possible. Finally the amyl alcohol is added, which 



is conveniently done with 

 the help of the apparatus 

 shown in Fig. 33 or in 

 Fig. 38 ; both of which 

 obviate the necessity of 

 sucking up the strong- 

 smelling liquid. In the 

 latter, the pipette is sunk 

 in the amyl alcohol as far 

 as the 1 c.c. mark, and by 

 simply closing the tube 

 with the finger the liquid 

 can be drawn out. 



It is important to use 

 the reagents in the proper 

 order, which is sulphuric 



acid, milk, amyl alcohol. 



FIG. 36. Crank-driven Centrifuge with ' . 



Heating Arrangement. 1 1 the sulphuric acid is 



followed by amyl alcohol 



and the milk last, then the result is sometimes incorrect. This 

 has been proved by Richmond and O'Shaughnessy, 1 and after- 



FIG. 37. Centrifuge without Heating Arrangement. 



wards also by Siegfeld 2 to be due to some unexplained chemical 



reaction between the sulphuric acid and the amyl alcohol, 



1 Analyst, 1899, p. 146. 2 Molkerei-Zeituny, Hildesheim, 1899, p. 433. 



