x] TESTING OF MILK 163 



that, as ordinarily carried out, it includes a determina- 

 tion of the total solids, the fat, and the ash. The 

 water and the solids not fat are calculated by 

 difference. The total solids are estimated by evapor- 

 ating at boiling temperature, on the water bath, a 

 weighed quantity of milk to dryness. The percentage 

 of ash is obtained by incinerating at a low red heat. 

 For the extraction of fat various methods are in use. 

 The most satisfactory one undoubtedly is that known 

 as Adam's coil process, which consists in absorbing 

 the milk by means of a coil of filter-paper, which is 

 then subsequently dried and transferred to a Soxhlet 

 extraction apparatus, where the fat is dissolved out 

 by ether and weighed. 



