22 



ANALYTICAL PROCESSES. 



string (previously bpiled with 

 water containing sodium car- 

 bonate to remove size and res- 

 inous matters) which serves to 

 prevent contact between the con- 

 centric folds of the coil, and is 

 conveniently passed through 

 holes in the paper. A cap of 

 filter paper is then placed over 

 one end of the coil and secured 

 by the ends of the string. The 

 coil is then suspended by some 

 simple means, the capped end 

 being downward, and 5 c. c. of 

 the milk to be tested, run on to the upper part from a 

 pipette. The milk is rapidly absorbed by the paper 

 and none filters through the cap. It is then dried in a 

 water oven for an hour or two. 



Sour milk must be weighed and thinned with a few 

 drops of ammonium hydroxid before absorption by the 

 paper. 



Heavy filter paper of good quality, which yields to 

 ether only a milligram or less, may also be employed, 

 as suggested by Thomson. One end of the strip is 

 fastened to some convenient support, and the other be- 

 tween the fingers. The paper being kept horizontal, 

 5 c.c. of the milk are taken in a pipette, and distributed 

 evenly over it, the end of the pipette being wiped on a 

 part left dry for the purpose. It is dried by passing to 



