1913] Walter Lewis Groll 513 



The refractometer is utilized by Wollny^^ on an ethereal Solution 

 of the fat obtained by extraction after the application of a special 

 reagent. The refractive power of the ethereal Solution of fat is 

 determined at 17.5° C. 



Maccagno and Mizzi^^ have devised a special apparatus in which 

 they treat the milk with a definite quantity of a Solution containing 

 ethyl alcohol, amyl alcohol and ammonium hydroxid. The per- 

 centage of fat is read off on the scale of the apparatus at a tem- 

 perature near the boiling point of water. 



By the Sichler " sinacidbutyrometer method,"^® the casein and 

 lactalbumin are dissolved by means of a Solution of sodium phos- 

 phate containing a small amount of sodium tri-citrate. The fat is 

 dissolved in isobutyl alcohol, which is called " sinol " in this method. 



In the Pilsner method/'^ the butyrometer is filled with 11 c.c. of 

 alkaline Solution (5 gm. of sodium phosphate, 15 gm. of neutral 

 sodium citrate, 30 gm. of sodium chlorid, 65 gm. of sodium 

 hydroxid dissolved in 600 c.c. of distilled water and filtered), 0.5 

 c.c. of isobutyl alcohol and enough sudan iii to color, and 10 c.c. 

 of milk and, after thoroughly mixing, the butyrometer and contents 

 are placed in a water-bath at 58°-62° C. and the temperature kept 

 above 55° C. In a half hour the butyrometer is removed, centri- 

 fuged and read. 



All the foregoing procedures, which include the important 

 methods, are open to criticism either because of the time consumed 

 in making the determinations or because of inaccuracy in the final 

 results. 



THE MEIGS METHOD 



The original Meigs method. The Meigs method, described 

 in this article, is neither extremely rapid nor simple but, everything 

 considered, it possesses certain advantages over each of the above 



1^ Hals and Gregg (Wollny method) : Milch-Ztg., 1902, xxxi, p. 433. 



15 Maccagno and Mizzi : Cheni. Centr., 1906 (3 qt), p. 633 (Rev. intern, 

 falsific, 1906, xix, p. 55). 



16 Cornalba (Sichler method) : Chem. Centr., 1905 (ii), p. yy (Stas. sperim. 

 agrar. ital., 1905, xxxviii, p. 227). 



1'^ Kundrat and Rosam (Pilsner method) : Chem. Centr., 1907 (i qt.), p. 513 

 {Milchwirtschaft. Zentr., 1907, iii, p. 20). 



