THE PREPARATION OF PELT 19 



laborious to carry out the whole process in one pit. In this 

 " one -pit system " the goods are inserted for (say) four 

 days in an old used lime liquor, with occasional handling ; 

 this liquor is then run to the drain and a new liquor made 

 up in the same pit, into which the goods are inserted for 

 (say) five days. They are then hauled and sent to the 

 unhairers. Each pack thus gets two liquors, old and new. 



A better method is the "three-pit system." In this 

 case each pack receives three liquors and has (say) three 

 days in each, first an " old lime," then a " medium lime," and 

 finally a "new lime." This system ensures a greater regu- 

 larity of treatment, and is deservedly the most popular 

 method for liming hides for sole leather. After being used 

 once as a " new lime," a liquor then becomes a " medium 

 lime," and after being thus used becomes the " old lime " 

 which receives the green hides from the soaks. The 

 system involves the goods being shifted twice to another 

 pit, which is more laborious than reinsertion into the old 

 pit, but if the limey ard be arranged in " sets " or " rounds " 

 of three pits, the shift is usually only to the adjacent pit. 

 One special advantage of this system is that the top hides 

 in one pit become the bottom hides in the next pit, and vice 

 versa. Rounds of more than three pits are sometimes used. 



Many factories have now adopted systems in which 

 there is no handling at all. The hides are suspended in lime 

 liquors which are agitated by mechanical contrivances (e.g. 

 Tilston-Melbourne process), or by jets of compressed air 

 (e.g. Forsare process). The goods are soaked and limed 

 " mellow to fresh" by changing the liquors by means of 

 pumps, air ejectors, etc. Thus the hides need no labour 

 from first being inserted until drawn for depilation. 



In liming, the whole of the epidermis as well as the 

 hair is loosened, and is subsequently removed in depilation. 

 The corium or true hide substance becomes much more 

 swollen by imbibation of water, and when taken out of 

 the new lime is " plumped " to very firm jelly. This 

 plumping is a matter of prime importance to the tanner. 

 The coarser fibres are thereby split up into the finer 



