88 



FOODS AND FOOD ADULTERANTS. 



to the areometer. The areometric degree is to be increased or dimin- 

 ished by the difference between the observed temperature and 17.5 0. as 

 the former is above or below the latter. The percentage of fat is taken 

 from a table which gives the numbers representing it for all degrees of 

 the Soxhletfs scale between 43 and G6 for whole milk, or 2.07 to 5.12 per 

 cent.; and for skimmed milk from 21.1 to 43, or from 0.00 to 2.07 per 

 cent. It is thus seen that the scale includes all percentages of fat from 

 nothing to 5.12. If a milk contain more than the latter percentage of 

 fat it must be treated with a certain proportion of water before it can 

 be examined by the Soxhlet's method. 



FIG. 1. 



Both Soxhlet in his original paper and Liebermann 1 affirm that the 

 ether retained in the form of an emulsion in the lower part of the liquid 



1 Zeit. Anal. Chem., 1884, p. 478, 



