CHAPTER IV.

_PUTREFACTION AND FERMENTATION._

The nature of ferments -- Organised and unorganised ferments -- Classification of organised ferments -- General properties of ferments -- The alcoholic fermentation -- The action of enzymes or unorganised ferments -- The destruction of ferments by heat and antiseptics -- The products of fermentation -- The fermentations of the tannery -- Fermentation in bating and puering -- Fermentation in the tanning liquors -- Moulds and mildews -- Control of fermentation PAGE 15