PREFACE. useful to those engaged in the dyeing and printing of textile fa, brics. The manufacture of coal-tar colours is an industr which cannot possibly thrive by the old rule of thumb may of doing business. It is a well-known fact that those who succeed best in this industry now-a-days spare no means to bring the highest scientific training to bear on the subject, while those who are penny wise and pound foolish endeavour to save the expense of adequate scientific advice, and thus ultimately find themselves completely surpassed by more enlightened rivals.The author acknowledges his indebtedness to Drs. Schulz and Julius, for permission to make use of their excellent Tabellarische Uebersicht del Kunstlichen Farbstoffe in compiling the tables of the azo-dyes on pp. 262-269. E. K. ERRATA. Page 43, Sth and 10th lines from top, read basic constituent or constituents, nstead of basic constituent or constituent. Page 42, 9th line from bottom, read It contains besides carbon, instead of It contains, besides carl on. Page 80, lines 4 ancl 7 from top, yead substitution derivatives, instead of substitutive derivatives. Page 282, line 15 from bottom, rend Primuline, insfsnd of Primuine. Page 304, line 7 from top, mad Liechti, instead oj Lie-chti. --This text refers to an alternate Paperback edition.