BY H. S. HALCRO VVAKDLAW. 



863 



electrical conductivity, 4'5 x lO""' reciprocal ohms; total solids, 

 13-24%; fat, 4-65%; solids not fat, 8-65%; lactose, 5-0%; ash, 

 0*72%; protein and extractives, 2*9%. 



The depression of tlie freezina-point, and the density were the 

 least variahle quantities measured. 



The concentrations of the constituents were much less variahle 

 than the total quantities obtained at a milking. 



The concentrations of the soluble constituents were much less 

 variable than those of the constituents in suspension. The concen- 

 tration of lactose was tlie least variable, that of fat the most 

 variable. 



About 3% of the samples contained a percentage of fat belo\v 

 3*2; about 40% of the samples contained a percentage of solids 

 not fat below 8*5. 



The mean percentages of fat and of ash were greater in the 

 milk of older cows ; the mean percentage of protein was less. The 

 percentages of the other constituents, and the properties, were not 

 affected by the age of the cow. 



The mean yields of milk became lower in the later stages of lac- 

 tation ; the mean percentages of lactose was also slightly lower 

 in the milk of the later stages of lactation, but the electrical con- 

 ductivity, and tlie percentages of fat and of protein became higher 

 as the stage of lactation became later. 



REFERENCES. 

 AcKERMANN. Jahrcsber. f. Tierch.. 32. 1013, 1903; (from Milchztg., 



31, 166 & 611. 1902). 

 Annett, Agr. Journ. of India. 10. 63, 1915. 

 Rartoletti, Encyclopaedia dogmatica, 1615; (cited by Alxierhal- 



den. Text-book of physiol. (hem., 39, 1908, trans, by Hall and 



Defren. New York : John ^Viley and Sons. 

 Beckmann, Jahresber. f. Tierch., 24. 225. 1894. 

 Board of Agriculture, London, Journal. 18. 30, 1911. 

 Camerer and Soeldner. Zeitschr. f, Biol., n. F.. 535. 1859 



■ , /hid., n. F., 18. 277. 1898. 



Carlinfanti. Gazz. chim. ital., 27, (i), 460, 1897. 

 Chapman, Proc. Linn. Soc. N, S. Wales, 33, 436, 1908. 



