BY H. S. FIALCRO AVARDLAW. 625 



are not charged electrically. They indicate, however, that any 

 charge carried must be small; much smaller, for example, than 

 that carried by the particles of a suspension of coagulated pro- 

 tein, which show verv evident movement in an electric field 

 under conditions similar to tliose described. 



Summary. 



(1). Removal of fat from milk increases the electrical con- 

 ductivity. 



('2). In a giv^en sample of milk, the increase of conductivity is 

 directly proportional to the volume of fat removed. 



(3). The increase of conductivity due to the removal of a given 

 amount of fat is not the same, however, in different samples of 

 milk. The average increase of conductivity due to the removal 

 of 1% by volume of fat is 1*5%. 



In conclusion, I wish to express my indebtedness to Sir 

 Thomas Anderson Stuart, in whose laboratory this work was 

 done. 



REFERENCES. 



Babcock. — Ann, Rep. New York Agrie. Expt. Station, 1885, 298, 1886. 



Chick and Martin. — Journ. of Physiol., 45, 261, 1912. 



Fleischmaxn. — Journ. f. Landwirts., 33, 251, 1885. Quoted in Somnier- 



feld's Handbuch der Milohkunde, 269, 1909. Wiesbaden : Berg- 



mann. 

 Jackson and Rothera. — Biocheni. Journ., 8, 1, 1914, 

 Oker-Blom.— Arch. f. d. ges. Physiol., 79, 510, 1900. 

 Shaw and Eckels. — U.S. Uept. Agric, Bur. Anim, Industrj', Bui. Ill, 



1909. 

 Taylor.— Journ. Proc. Roy. Soc. N. S. Wales, 47, 174, 1913. 

 Wardlaw. — These Proceedings, 1917, xlii., 815. 



