_WATER AS USED IN THE TANNERY._
Impurities of natural water -- Hardness -- Soap test -- Temporary
hardness -- Clark’s softening process -- Archbutt and Deeley’s
softening apparatus -- Other appliances -- Effect of temporary
hardness in tanning and dyeing -- Permanent hardness -- Boiler scale
-- Mud -- Iron -- Alumina -- Soda -- Copper, lead, etc. -- Sulphuric
acid -- Nitrates and Nitrites -- Chlorine -- Carbonic acid -- Silicic
acid -- Effect of hardness on plumping -- Peaty waters PAGE 93