EDITOR'S PREFACE. MR. G. AUERBACH's monograph on Anthracen and its Derivatives is generally recognised both by manufacturers and by scientific theorists as the authority on this interesting and important section of organic chemistry. It presents us with a summary of all important researches on the subject, compiled and digested by one who has made the anthracen derivatives his speciality, and who has had great practical experience in some of the most eminent establishments for the manufacture of artificial alizarin. An English version of this work has been for some time considered as a desideratum by all persons interested in the production and in the application of artificial colouring matters. The present edition is founded upon a manuscript copy carefully revised and extended by the author so as to embrace all the most recent improvements. All temperatures throughout the work are stated according to the Centigrade scale, and the specific gravities of liquids are given as on Baume's hydrometer. AUTHOR'S PREFACE. WHEN the first German edition of this book (Seehagen, Berlin) appeared four years ago, it was my purpose to render it as complete as possible, so that every one might find in this monograph all researches bearing upon Anthracen and its Derivatives duly classified, without requiring to search for the memoirs scattered through scientific journals. But if this object was almost attained four years ago, so many novel and important facts have been ascertained since that date, that the book requires to be remodelled and rendered complete. Thus, in a technological point of view, we may instance the discovery of accurate methods for determining the value of anthracen, whereby the utterly untrustworthy processes with alcohol and bisulphide of carbon have been superseded; further, the researches on the formation of alizarin from monosulphanthraquinonate of soda, &c. On the other hand, in the purely scientific region we may mention the beautiful researches of Baeyer and Caro on the synthesis of anthraquinon derivatives from phthalic acid and phenolen; the investigations of Lieber mann on chrysammic acid, and many other investigations of distinguished interest. In general, the plan of the earlier edition has been adhered to, but has been rendered more systematic. The isomeric compounds have been arranged in groups so as to admit of an easier survey. The arrangement of the bibliographical appendix has been retained as far as practicable. In order that the work may fulfil its object as a complete monograph of Anthracen and its Derivatives, I respectfully request all chemists engaged in the study of this subject to point out to me any memoirs which may have escaped my notice, and kindly to forward me copies of the journals in which such researches have appeared. May the work serve to draw increased attention to the study of this interesting compound and of its derivatives! G. AUERBACH. SUDBURY, MIDDLESEX : |