4 BULLETIX 1100, U. S. DEPARTMEXT OF AGRICULTURE. 



condition. The samples are again dried, at 50° C. for three hours, 

 and weighed. 



The samples are next washed with soap and water at a tempera- 

 ture of from 40° to 45° C. for three-quarters of an hour. (See Fig. 

 5.) About one-half pound of neutral soap is placed in the first vat 

 containing 150 gallons of water. After washing the samples, the 

 water is squeezed from them and they are placed in a second vat 

 and washed for half an hour in clear water at a temperature of from 

 40° to 45° C. When washing extremely dirty wool, one-quarter of 

 a pound of neutral soap is added to the 150 gallons of water. in the 



Fig. .3. — Grease extraction apparatus. Extraction containers are shown in the right half of thisilius- 

 tration, with filter papers beneath. The baskets of wool are placed in these containers and gasoline is 

 poured into the containers until within 2 inches of the top Lids are placed on the containers after the 

 agitating process, and the gasoline is allowed to stand 45 irinutes. Upon filtering, the gasoUne returns 

 to the pressure tank, A. It is then forced into the distillation tank, B, condensed in tank, C, and re- 

 turned through the collecting tank, D, and the upper pipes into can, E. At F is shown the card file 

 bearing the weekly schedule of work. A card is used for each day's program. This schedule is shown 

 in full on page 17. 



second vat and the wool is again washed for 30 minutes, but soap 

 is not used in the second vat unless the wool is extremely dirty. 

 In case soap has been used in the second vat the water is squeezed 

 from the wool and it is washed a third time in clear water at the 

 same temperature. After the samples have been washed in one 

 clear water for 30 minutes the water is squeezed from them by the 

 use of a wTinger; they are put into the original containers and dried 

 in the blower-drver at 60° C. for eight hours, allowed to stand over- 

 night, and conditioned in the concUtioning oven for three hours. 

 The weight of the grease is found by the difference in the weight of 

 conditioned, greasy wool and the conditioned weight of the sample 

 after three washings with gasoline. Likewise the weight of the dirt 

 is found by the difference in the weight of the conditioned wool 



