An Encyclopedia of the History of Technology part 23. This one of a kind encyclopedia presents the entire field of technology from rudimentary agricultural tools to communication satellites in this first of its kind reference source. Following an introduction that discusses basic tools, devices, and mechanisms, the chapters are grouped into five parts that provide detailed information on materials, power and engineering, transportation, communication and calculation, and technology and society, revealing how different technologies have together evolved to produce enormous changes in the course of history | PART ONE MATERIALS at the ripe old age of 35 and devote his time to chemical research. Other chemists followed in his wake with other dyestuffs derived from aniline. It was found that aniline could be subjected to the diazo reaction lately discovered by Peter Griess and so named because two nitrogen atoms were involved. When the product of this reaction is treated with phenol highly coloured substances are formed many yielding satisfactory dyes. The first azo dye was Bismarck brown prepared by Carl Alexander Martius in 1863. The next nut to crack was the synthesis of the red colouring matter in madder alizarin. The elucidation of its structure had to await further progress on the theoretical side and this was forthcoming when August Kekule realized that benzene had a cyclic structure that is the six carbon atoms in the benzene molecule were joined up in a ring visualized as the famous hexagonal benzene ring. Following on this Graebe and Liebermann were able to work out the structure of alizarin and then to devise a way of synthesizing it on a laboratory scale. It was however Heinrich Caro a chemist responsible for many advances in this field who worked out a manufacturing process for synthetic alizarin involving sulphonation of anthraquinone with concentrated sulphuric acid while working for the firm Badische Anilin- und Soda-Fabrik. Perkin was working along the same lines and was granted a patent for his process on 26 June 1869 one day after Caro received his. A friendly settlement was reached allowing Perkin to manufacture alizarin in Britain under licence from BASF. The synthetic dye was much cheaper than the natural version so the maddergrowing industry fell into rapid decline and expired. Success with alizarin stimulated chemists to turn their attention to indigotin. After many years of research in which Adolf van Baeyer figured prominently the molecular structure was found and in 1880 a method of synthesizing indigotin described. Again the transition to .
