376 MANUAL OF FARM ANIMALS 



hay, and the hke. This foreign material is very injurious to 

 the fleece, as it is difficult to remove, does not absorb dyes, 

 and interferes in the manufacture of cloth. 



Luster refers to the glistening appearance of the fiber. On 

 being held in the light the fiber appears as if it were varnished. 

 Luster is independent of oil, as fibers possessing a small amount 

 of oil or yolk may be very lustrous, while other fibers possessing 

 much oil may be rather dull. The significance of this luster is 

 that wool possessing it more readily takes delicate dyes. 



Brightness refers to the color of the fibers. Wool is spoken of ' 

 as bright or dark, the former signifying a clear white color, the 

 latter signifying the darker colors. 



Yolk refers to the oil or grease that is found, in the wool. 

 This oil is readily recognized by running the hand over the 

 wool. The various breeds differ widely in the amount of oil 

 secreted and the amount is influenced by the food. Yolk is 

 desirable as the fleece is much softer, more compact, as well as 

 brighter and cleaner, and in addition it indicates thrift in the 

 sheep. Excessive quantities of yolk are of no advantage, and 

 may be a source of direct loss, especially in the manufacturing 

 of woolens. 



Summary. — In the examination of wool, therefore, one must 

 consider first the quantity, second the quality, and third the 

 condition. Under quantity note the covering over the entire 

 body, including the belly and arm pits, also the density and 

 length which should be even over the entire body; under 

 quality note the softness, crimp, and soundness; and under 

 condition note the purity, luster, brightness, and yolk. 



