270 ANIMAL PROTEINS 



primary consideration. Unfortunately this sometimes 

 results in the neglect of the pelt. The removal of wool 

 from sheepskins forms a special industry known as " fell- 

 mongering," which has been previously described (Part II., 

 Section IV., p. no). Pains are taken to clean the wool 

 even before removal from the pelt, by the liberal use of 

 water and the " burring machine." There is much variation 

 in quality, and care is taken to keep the various grades 

 separate, even during the " pulling " operation. From the 

 fellmonger the wool passes to the " wool stapler," and 

 forms the basis of one of our most important mechanical 

 industries, the manufacture of woollen cloths. Wool is also 

 removed from sheep by the periodic shearing, and in this 

 case does not reach the fellmonger at all. 



Apart from the raw material itself, there are few -bye- 

 products of the leather trades which are of commercial 

 importance. The sludge from the pits of the limey ard 

 contains, in addition to much lime and chalk, a certain 

 proportion of protein matter. This is derived partly from 

 the blood and dung associated with the hide, partly from 

 the solution of the corium hide substance, partly from the 

 solution of the softer keratins, and partly also undissolved 

 and loose hair. This bye-product is rather difficult to 

 deal with, as it will not easily dry. It is indeed sometimes 

 a problem to dispose of it, except in rural districts, where 

 the farmers appreciate its manurial value and will usually 

 cart it away for a nominal fee. Where possible, it is better 

 to let it drain and settle on land, and pile it up in heaps to 

 dry further. Soak-pit sludge has a distinctly greater value 

 as manure, on account of the greater proportion of dung 

 proteins. As some lime is often used in these pits, the 

 product is a really useful fertilizer. 



The only other bye-product of the leather trades is 

 waste leather itself. For small pieces of leather there is 

 always some little opening in producing small articles, such 

 as washers for taps, etc., and there is also the possibility of 

 shredding or pulping and making an artificial leather. The 

 best leather substitutes, indeed, are made from waste 



