BYE-PRODUCTS OF THE LEATHER TRADES 269 



commercial value. The horns of cattle are now almost 

 invariably removed before reaching the leather manu- 

 facturer, but have some little value. This part of the 

 epidermis is not solid keratin. A " pith " is easily removed 

 after boiling in water. The outer parts, too, are often 

 coarse and somewhat damaged, but if removed by scraping 

 reveal often a rather beautiful structure of varying colour. 

 There is some opening for this product in the manufacture 

 of small articles of horn, but much of it, together with 

 hoofs, is roasted and crushed for making fertilizers. The 

 hair of cattle, goat, etc., has also a commercial value. This 

 is removed after liming, and needs subsequent purification 

 (Part I., Section II., p. 22). The hair is well washed with 

 water, using either repeated changes or a continuous supply, 

 the operation being carried out in paddles or similar 

 machines which stir up the hair in the water. When clean, 

 the hair is transferred to a centrifugal machine or " spinner," 

 in which much adhering water is removed. This is a great 

 assistance in drying out, which is the next and final operation. 

 In drying, the hair is laid upon steam-heated boxes or pipes, 

 and a current of warmed air passed over or through it by 

 means of a fan. It is better to have the hair " turned "- 

 occasionally. This ensures quicker as well as more even 

 drying. The product is made up into large bales and sold 

 for the manufacture of felts, mattresses, etc. White hair 

 is usually kept separate and commands a larger price. 

 The power consumed hi driving the washing machinery, 

 the centrifuges and the drying fan, together with the fuel 

 required for the drying steam, and the labour involved 

 throughout, make it doubtful whether this bye-product is 

 worth either the capital outlay or the working costs neces- 

 sitated. Many manufacturers avoid this treatment alto- 

 gether, therefore, and the wet limed hair is sold direct to 

 the fertilizer factory. A less price is obtained, but much 

 expense is saved. Especially when the animals have only 

 their short summer coats, this course is preferred. 



In the case of the wool from sheepskins the product 

 is much more valuable. The wool, indeed, is often the 



