FERMENT

(Lat. ferveo, I boil.) The substance which is e ential to the proce of fermentation. It is either naturally present m the fermentable juice, as in the grape; or it is added, as in tlie manufacture of beer, where yeast constitutes the ferment. Ferments are of an albuminous or glutinous character; the presence of nitrogen seems e ential in their composition, hence they are cla ed by chemists among azotised compounds. Their modus operand i is still unexplained. [s. 458]