SELECTION OF MILK COWS. 381 



to hurt them, reappear in their milk in quantity large enough to 

 impart noxious properties to it. 



"All the causes which make the quantity of the milk to vary 

 labor, drinks, perspiration also modify its composition, and 

 consequently its qualities. In general, cows which perspire little 

 and give most milk, give it inferior. 



"Temperament exerts a great influence on the quality of tho 

 milk; for, of several cows, placed under the same apparent con- 

 ditions, and fed in the same way, some give a better milk than 

 others; but the causes which determine these differences are 

 unknown, and we cannot give any mark which ascertains their 

 effects with certainty. 



"Still, according to M. G-uenon, there is a correspondence 

 between the composition of the milk, and the state of the skin 

 which covers the perinseum, or twist ; a soft, unctious skin, of a 

 yellow saffron color, parting with a fine, yellowish dust, when it 

 is rubbed, and a fine, pliant, furry hair, indicate a milk of good 

 quality, and rich in butter. 



"We know only one method of ascertaining the qualities of 

 milk, and that is by examining it ; good milk is of a very slightly 

 yellowish-white color, and of considerable consistency; its con- 

 sistency may be ascertained by pouring it in little drops on a 

 solid body. Bad milk, of a bluish and watery white, spreads in 

 thin sheets when it is poured out. 



"Some persons have the organ of taste in sufficient perfection, 

 to determine the quality of the milk by sipping it. 



"As to the dust which adheres to the perinaeum, or twist, and 

 whose unctious feel, fineness, and yellow color, indicate, accord- 

 ing to some authors, a buttery milk of good quality, we have 

 never been able to study it, though we have often tried on cows 

 whose milking qualities we knew to be very good. 



"The nature of the dust taken from the skin, and the state of 

 cows in regard to flesh, may one day furnish indications as to the 



