180 H. B. TAYLOR. 



small interchange of the percentage values between 

 potassium chloride and citrate would therefore make an 

 appreciable change in the conductivity of the milk. The 

 conductivities given below in Table VI represent the 

 specific conductivities of a series of milks at 26° C, and 

 the corresponding ash as obtained by burning off the organic 

 matter at a temperature below read heat. 



Table VI. 

 Specific Conductivity x 10 2 . Ash per cent. 



•4282 '71 



•4651 *72 



•4467 *72 



•4642 -73 



•4572 -76 



•4623 '79 



From the above figures it is seen that the conductivity 

 is not proportional to the ash. The difference is probably 

 due not only to the variation in composition of the ash but 

 also to the presence of varying amounts of other con- 

 stituents. 



Increase in conductivity due to the removal of fat. 



When fat is separated from milk the conductivity 

 increases. This increase is probably due to two things — 



(1) the increase due to the concentration of the salts, 



(2) that due to the removal of obstacles from the path 



of the ions. 



In regard to the first, the analyses of a sample of milk, 

 before and after 4*5 per cent, of fat was removed are given 

 below; it will be seen that the figure for the solids not fat 

 in the separated portion is 4*5 per cent, higher than in the 

 original sample. 



Before separation. After separation. 



Total solids 14*29 lO'lO 



Fat 5*15 '60 



Solids not fat 9*14 9*50 



