INTRODUCTORY 



I. HISTORICAL 



THE history of organic chemical synthesis has been so frequently 

 dealt with by previous writers that it is unnecessary to discuss the 

 subject in detail from this point of view. In so far as the existence of 

 a special ' vital force ' was considered necessary to explain the forma- 

 tion of organic compounds by the living organism, it is generally 

 conceded that Wohler, by his synthesis of urea from ammonium 

 cyanate in 1828, was the first to deliver a serious blow against the 

 doctrine in question. As a pioneer in the same field our own country- 

 man, Henry Hennell, must, as I ventured to plead in 1895 l , be accorded 

 a place not inferior to that of Wohler as being among the first to 

 produce an organic compound independently of the living organism. 

 The English chemist succeeded in synthesising alcohol from olefiant 

 gas at practically the same time that his great German contemporary 

 had excited the interest of the whole chemical world by his synthesis 

 of urea. 



Important as was the latter discovery, it must not be forgotten that 

 at the time of its announcement the synthesis was not what would now 

 be termed ' complete,' because the cyanide from which the cyanate was 

 prepared was then obtained by fusing nitrogenous organic matter with 

 an alkaline carbonate, so that it might have been said that the carbon 

 and nitrogen were both of vital origin. The synthesis of alcohol by 

 Hennell was equally incomplete, because the olefiant gas had been 

 obtained by the pyrogenic decomposition of organic material, viz. oil, 

 so that in this respect the two syntheses were on precisely the same 

 level. 



Since alcohol was not in 1828 recognised as a vital product in the 

 same sense that urea was so regarded, it will be easily understood why 

 the synthesis of the former failed to arouse any particular interest at 

 the time ; the discovery did not clash with the current notions of 

 Vitalism. As Hennell's contribution to chemical synthesis had of late 

 years been allowed to fall into oblivion, I thought it desirable in 1 895 

 to remind chemists once again of his claim to take rank among the 

 early pioneers in this field. The plea has not, however, been allowed 

 to pass unchallenged, for no less an authority than M. Berthelot, one 

 of the most active and distinguished among the later workers at the 

 subject of chemical synthesis, has denied Hennell's claim to have been 

 the first to synthesise alcohol 2 . Under these circumstances it will be 



1 Brit. Assoc. Rep. Ipswich, 1895, p. 649. a Comp. Rend. 1899, 128, 862. 



B 



