MILK AND MILK PRODUCTS 17 



those obtained by the Adams process, and are generally even 

 closer. 



For great accuracy, the factor for correcting the reading on 

 each of the bottles should be determined by comparison with 

 the figures obtained by the Adams or other standard pro- 

 cess. 



Cream is to be diluted to exactly ten times its volume, the 

 specific gravity taken, and the liquid treated as a milk. Since 

 in the graduation of the test-bottles a specific gravity of 1.030 

 is assumed, the reading must be increased in proportion. 



A more accurate result may be obtained by weighing in the 

 test-bottle about 2 c.c. of the cream and diluting to about 15 c.c. 

 The reading obtained is to be multiplied by 15.45 and divided 

 by the weight in grams of cream taken. 



The mixture of fusel oil and hydrochloric acid seems to be- 

 come less satisfactory when long kept. It should be clear and 

 not very dark in color. It is best kept in a bottle provided with 

 a pipet which can be filled to the mark by dipping. Rigid 

 accuracy in the measurement is not needed. 



See also Cochrarfs method under "Condensed Milk." 



Calculation Methods. Several investigators have proposed 

 formulae by which when any two of the data, specific gravity, 

 fat, and total solids, are known, the third can be calculated. 

 These vary according to the method of analysis employed. 

 That of Hehner and Richmond, as corrected by Richmond, 

 was deduced from results by the Adams method of fat extrac- 

 tion, and has been found to be the most satisfactory. It is as 

 follows : 



T =* 0.25 G + 1.2 F + 0.14; 



in which T is the total solids, G the last two figures of the specific 

 gravity (water being 1000), and F the fat. A table based upon 

 this formula is annexed. 



A formula has been devised by Richmond by which the lac- 

 3 



