PART VI. MISCELLANEOUS PROTEINS 

 AND BYE-PRODUCTS 



SECTION I. BYE-PRODUCTS OF THE 

 LEATHER TRADES 



IN the leather trades by far the most important and valuable 

 bye-products are obtained from the hides and skins them- 

 selves, and all these are obtained before the tannage proper 

 is commenced. The leather trades use only the dermis 

 (corium) or true skin for the manufacture of leather, and as 

 we have noted (Part I., Section II., p. 16) this prepared and 

 purified dermis is called " pelt/' The cuttings and trim- 

 mings from the pelt form the most valuable bye-product of 

 the leather trades, and are the raw material of the gelatine 

 and glue industries (Part V., Section II., p. 221). Many 

 portions of the pelt, indeed, such as ears, noses, and cows' 

 udders, are quite useless for any other purposes. Other 

 portions, such as cheeks, faces, and even bellies, may be 

 made either into glue or leather according to the state of 

 trade. Hardly less important to the same industry are the 

 cuttings of adipose tissue removed in " fleshing " the hides 

 and skins. These, though yielding less protein, yield also, 

 however, the valuable animal greases (Part V., Section II., 

 p. 227). To obtain both these products in a purer condition 

 the removal of " flesh " after " soaking," but before 

 " liming " (Part I., Section II., p. 18), has been favoured by 

 some, especially in America. 



Amongst the epithelial structures of the hides and skins, 

 we have several protein bye-products which have some 



