ALUM TANNAGES 177 



obtained with logwood and iron. After re-egging, the 

 skins are dried out and staked. They are " seasoned " 

 with a weak emulsion of soap and oil, dried, oiled lightly 

 with linseed oil, ironed, re-oiled and finally brushed. Whites 

 are undyed, and 10 Ibs. French chalk per 100 skins is used 

 in re-egging. 



" Calf kid " is a once popular but now obsolete upper 

 leather made by tawing calfskins. The skins were well 

 plumped in limes, delimed by washing and drenching, 

 tawed much as for glove kid, split, dried out rapidly, staked 

 and aged. They were finished dull and black with soap 

 and wax. 



The various white leathers used for belts, laces, whip 

 lashes, aprons, covers for stoppered bottles, etc., are very 

 usually made with an alum tannage. Alum, salt and flour 

 only are used. Whitening is also mixed in and acts as 

 neutralizing agent as well as pigment dye. 



Wool rugs are manufactured from suitable sheepskins 

 by an alum tannage. They are first well cleaned, using 

 soap on wool and flesh. They are next degreased by 

 painting with fuller's earth paste and drying. They are 

 tawed by painting the flesh with a strong solution of alum 

 and salt, or even by rubbing on the solid salts. They are 

 dried out, aged and sorted for suitable colours. The 

 dyeing is rather difficult, as many artificial dyestuffs are 

 of no use. It is usual to bleach the skins iirst in a weak 

 solution of bleaching powder, and afterwards to dye with 

 infusions of the dyewoods, e.g. logwood, fustic, sandal- 

 wood, terra japonica, quercitron bark, turmeric, indigo, 

 etc. Vat dyeing is usual. After dyeing, retanuing with 

 alum and salt is necessary, on account of the loss of these 

 in bleaching and dyeing. Rugs are usually finished black, 

 white, ^rcy, brown, walnut, crimson, blue or green. 



REFERENCES. 



Procter, " Principles of Leather Manufacture," pp. 184, 236. 

 Bennett, " Manufacture of Leather," pp. 239, 371. 



12 



