PREFACE. ORGANI d C e rivatives of arsenic appeal to the scientific public for two widely different reasons. From the historical standpoint these substances are of considerable interest because they have been under investigation throughout a period of time coeval with the birth and development of modern chemistry. Successive generations of chemists have examined these compounds from points of view which varied with the gradual evolution of chemical science, and the results of their researches have played an important part in the establishment of current theories of the molecular constitution of matter. Additional importance is conferred on the subject by the circumstance that very early in the study of organic arsenical compounds it was realised that, in these synthetic products, the physician has at his disposal substances of great physiological potency. It is chiefly this medicinal attribute of organic arsenicals which has evoked the more recent activities in the synthesis of organo-metalloidal compounds. These utilitarian investigations have not been restricted to organic arsenicals, but have extended to the corresponding derivatives of antimony, and accordingly these related products are also discussed in the present monograph. Both series of organo-metalloidal compounds are already so extensive that a detailed description of every individual member would render this treatise unduly bulky, but a liberal selection has been made comprising those substances having either a practical application or some aspect of theoretical interest. A bibliography of the most important researches and treatises down to the end of 1917 has been included, and these references to original memoirs supply the necessary clue to further information regarding any known organic arsenical or antimonial which may I in the future acquire increased prominence. v PRBFA C17 It is my pleasant duty to express my grateful thanks for assistance received in the compilation of this monograph from the following firms --Les gtablissements Poulenc Fr res, Messrs. Burroughs Wellcome Co., and Messrs. May and Bal. er. I also desire to acknowledge the friendly help received from Dr. W. H. Martindale, from Mr. E. Sciloll, formerly of thc, Farbwerke vormals Meistcr, Lucius, und Briining from Ail-. F. W. Clifford, Librarian of the Chc nical Society and from Messrs. E. D. Evens, BSc., and 117. R. Grist, who have assisted me in reading the proofs md in arranging the index and bibliographic data. G. T. M. CITY AND GUILDS T ECHNIC C A O L L LEGE, F INSBURY, LEONARSDT REET1,-ONDO E. N C. . 2 . I-. P I FAcE. . . . . . . . . . . ix ISTR DUCTION . . . . . . . . . . . . xi Chemical . . . . . . . . . . . . xi Historical. . . . . . . . . xii CACODYL . . . . . . . . . . . . . I Enrliest Reseavcltes on Organic Arsenical . I Section I. Cadets fuming arsenical liq ii . l . . . . . I .. 11. Cacodyl and its derivntivca . . . . . . 3 . . 111. Homologues of cacodyl . . . . . . . I 7 ALIPHATIC . R SENICALS A X A N. TI I KIAI . . S . . . . . 2 0 Sy z heses of Allzyl Organo-metalloidal C O I I Z I O Io z f S , i Airzsnengi c and Antimony . . . . . . . . . . . z o Section I. General Reactio ls . . . . . . . . 2 1 .. 11. Alipllntic arsenic C O I I I I L I L . - . . . . . 3 2 .. 111. Xliphntic antimony r o m p u r . t l , . . Aao. la . c R S SICAI. . ...