322 



BUTTER. 



Blank experiments should be performed ; the figure for the 

 soluble blank may be sometimes high (2 c.c), without affecting 

 the accuracy of the results. 



The soluble acids obtained by the Poleuske process are prac- 

 tically the same as those given by the Reichert-WoUny method. 



The average figure for the soluble fatty acids is 28 '4 c.c, but 

 considerable variation is observed ; in very rare cases figures 

 slightly exceeding 40 have been obtained, while exceptional 

 low figures of 14 have been observed as lower limits. These 

 very high or very low figures are rare ; low figures have usually 

 been observed in cases where the butter is produced from the 

 milk of cows near the end of lactation, especially if the animals 

 have been exposed to inclement weather. 



The average of the results of different observers shows that 

 out of 100 samples 



3 will probably yield Reichert-WoUny figures over 30 c.c. 

 86 „ , „ ,, between 26 and 30 c.c. 



7 „ „ „ ., „ 25 and 26 c.c. 



3 „ , ,, „ below 25 c.c. 



All samples giving below 25 c.c. may be looked upon as sus- 

 picious, and should be further investigated. 



The Polenske figure varies with the Eeichert-Wollny figure, and 

 the following table shows the relation : — 



Coco-nut oil gives a Reichert-Wollny figure of 7 to 9 c.c, 

 and a Polenske value of 16 to 18 "5. 



Should the Polenske figure exceed the maximum given in the 

 table the quantity of coco-nut oil present may be deduced from 



P — P' 



the formula C = —^n-r- X 100. 



C = percentage of coco-nut oil. 

 P = Polenske figure. 



P' = mean Polenske figure from the table for a figure equa 

 to the Reichert-Wollny figure found -f- half the Polenske figure. 



