UNITED STATES DEPARTMENT OF AGRICULTURE 



^^m§- BULLETIN No. 1100 ^ 



jdh^%j-t. 



Washington, D. C. 



September, 1922 



A METHOD OF DETERMINING 



IN WOOL. 



GREASE AND DIRT 



By D. A. Spencer, Senior Animal Husbandman in Sheep and Goat Investigations, 

 J. I. Hardy/ Sheep Husbandman, and Mary J. Brandon, Scientific Assistant 

 in Sheep and Goat Investigations, Animal Husbandry Division, Bureau of Animal 

 Industry. 



CONTENTS. 



Page. 



Object of this investigation 1 



Method of obtaining data 1 



Experimental work 2 



Index figures for grease and dirt 2 



Basis of the index figures 5 



Conditioning for weighing 6 



Experimental work. — Continued. 



Determining weight of grease , 



Determining weight of dirt 



Weekly working schedule 



E xplanation of wool-scouring data slieet , 

 Summary 



Page. 

 11 

 15 

 15 

 19 

 20 



OBJECT OF THIS INVESTIGATION. 



The object of the wool-scouring investigation, here discussed is to 

 afford a fair basis for comparing the grease and dirt indices of va- 

 rious wools, the indices to be used to divide wools into groups for the 

 study of other qualities affected by or associated with grease and 

 dirt contents, such as length of fiber, fineness, density of fleece, spin- 

 ning quality, strength, and weight of clean wool per fleece. Data 

 obtained are to be used in planning the mating of the sheep that 

 grow the fleeces studied for the purpose of fleece improvement in 

 the qualities mentioned. 



METHOD OF OBTAINING DATA. 



Sheep-breeding investigations conducted by the Bureau of Ani- 

 mal Industry, United States Department of Agriculture, involve 

 extensive studies in fleece improvement. Individual fleeces of 

 about 2,000 sheep are studied each year, and the problem of obtaining 

 data on the net yield of clean wool from each fleece has prompted 

 the development of a method of single-fleece determination that 

 would yield dependable results without necessitating the complete 



1 Moisture experiments reported in this bulletin were conducted by J. I. Hardy diu-ing the winter of 

 1919 and 1920. Doctor Hardy resigned from the department in February, 1920. 

 111962— 22— BuU. 1100—1 



