i8 ANIMAL PROTEINS 



drum or paddle before pit soaking is extremely useful to 

 effect the rapid removal of superficial salt, and is also 

 useful after pit soaking to remove the last traces. 



Dried and dry-salted goods need a soaking still more 

 prolonged, up to one week if water alone be used. With 

 the assistance of caustic soda, however, the process can be 

 shortened to about two days. The first soak liquor should 

 consist of a 0*1 per cent, solution of caustic soda, and after 

 the goods have been inserted twenty-four hours, they will 

 be materially improved by a few hours' drumming or 

 paddling. Another caustic soda soak will complete the 

 process. Sodium sulphide crystals may replace caustic 

 soda, but about three times the weight will be needed. 

 Carbonate of soda and caustic lime also are a convenient 

 commercial substitute for caustic soda. For 10 Ibs. caustic 

 soda, use 36 Ibs. carbonate and 7 Ibs. lime. Extra lime 

 should be added in all cases when the water is hard. Acid 

 liquors will also soften dried and dry-salted goods, but 

 such processes do not fit in so well with the subsequent 

 liming. The use of putrid soaks and stocks may be now 

 considered out of date. 



Liming follows soaking, and consists essentially in 

 immersing the hides for 7-10 days in milk of lime. The 

 chief object in view is to loosen the hair and prepare for 

 its mechanical removal. Liming takes place in pits, the 

 tops of which are level with the limey ard floor. The lime 

 is slaked completely and mixed well with water in the pit, 

 being particularly well plunged just before the insertion 

 of a pack of goods. Saturated limewater is only a 0*13- 

 per-cent. solution. The goods are occasionally " handled," 

 i.e. hauled out of the pit and reinserted after plunging 

 ("hauling" and "setting"). This is necessary to keep 

 the liquor saturated with lime. The hides are inserted 

 one by one, each being " poked down " to ensure its contact 

 with the liquor. The goods are invariably immersed first 

 in a previously used lime liquor. Most tanneries now carry 

 this out in a systematic way, so as to ensure regularity in 

 the process. As the goods are large and heavy it is less 



