SYNTHETICAL DRUGS 



By G. T. MORGAN, D.Sc, F.I.C. 



Royal College of Science, London 



The medicaments falling into the category of synthetical drugs 

 are those which are built up by chemical means from simpler 

 carbon compounds, and not extracted ready-formed from 

 products of the vital activities of plants or animals. In this 

 article it is intended to discuss in simple terms the chemical 

 nature of a typical selection of these therapeutic agents, the 

 trivial or commercial names of which are often household 

 terms. 



In 1906 chemists from all parts of the world gathered 

 together in England to celebrate the jubilee of the coal-tar 

 industry, the fiftieth anniversary of the discovery of the 

 colouring matter, mauveine, by the late Sir William Perkin, and 

 1906 may also be regarded as the jubilee year of the synthetical 

 drugs, for it was in an attempt to synthesise from aniline 

 the valuable alkaloid, quinine, that Perkin discovered mauveine, 

 his researches on aniline being the pioneers of other investi- 

 gations which led to the employment of this remarkable base, 

 aniline, in the production of compounds of therapeutic value. 

 It is therefore, at the outset, necessary to consider, even though 

 very briefly, the chemistry of aniline and its parent hydrocarbon, 

 benzene. The latter substance, discovered by Faraday in 1825, 

 is the chief constituent of the volatile oil obtained on distilling 

 ordinary coal tar. Chemical analysis shows that the compound 

 consists of twelve parts of carbon united with one part of 

 hydrogen or, in the language of the atomic theory, one atom 

 of carbon combined with one atom of hydrogen. Furthermore, 

 a consideration of its vapour density and other physical 

 properties indicates that a molecule of this hydrocarbon — 

 that is, its smallest conceivable part — is somewhat complex 

 and contains no less than six of these pairs of atoms. A 

 general survey of the compounds of carbon shows that this 

 element possesses in a marked degree the property of accumu- 



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