CLEANLINESS 317 



but there should be no justification for breeding excessive quanti- 

 ties of it merely for the sake of increasing the weight of the fleece. 

 Cleanliness. Dirt, sand, burs, straw, and chaff in wool not only 

 decrease its scoured yield, but also affect its value. It is impossible 

 completely to scour out burs, straw, and chaff, and if the wool con- 

 taining them is to be made clean it must be treated with a weak 

 solution of sulphuric acid and heated, a process known as car- 

 bonizing and one which is likely to weaken the wool. The con- 

 ditions under which the sheep must be kept may make it impossible 



FIG. 199. Tender wool, showing break caused by disease or improper nourishment of the 

 animal on which the wool was grown. (U. S. D. A. Bulletin 206.) 



to keep out dirt and sand ; on some of the ranges in the western 

 parts of the United States, it is not altogether possible to keep 

 out burs, but on farms the presence of chaff, straw, and burs in 

 wool is largely the grower's fault. Backs should be used that will 

 not let chaff fall into the wool on top of the neck and shoulders 

 and the flock should not be allowed to feed continually at stacks 

 of straw. 



Branding sheep with insoluble paint is very detrimental to 

 the condition of wool because the paint cannot be scoured out. 



