CHAPTER XV.

_IRON AND CHROME TANNAGES._

Iron tannages -- Chrome tannages -- Chemistry of chromium compounds -- Knapp’s method of chrome tannage -- Cavallin -- Swan -- Heinzerling -- Hummel’s improvement -- Schultz’s method -- Theory of the two-bath process -- Practical management of the two-bath process -- Dennis’s chrome tanning liquor -- Procter’s liquors -- Theory of basic process -- Practical use of basic liquors -- Washing and neutralisation -- Effect of sulphur on chrome leather -- Bluebacking -- Fat-liquoring -- Dyeing of chrome leather -- Glazing and finishing PAGE 198