A large number of cotton mills furnish the chief source of industry; printing, dyeing and bleaching of cotton and calico, spinning and weaving machine making, iron and steel works, and collieries in the neighbourhood, are also important.
Dyeing is another large trade, as is the preparation of indigo.
The salt is used as a mordant in dyeing and calico-printing.
Stannous chloride is largely used in the laboratory as a reducing agent, in dyeing as a mordant.
If you're dyeing your hair and only going one shade lighter or darker, consider doing it yourself.