THIAZINES  , in organic

chemistry, a series of cyclic compounds containing a ring system of four carbon atoms, one nitrogen and one sulphur atom . These may be grouped in three ways, giving the following skeletal structures: CCN C'NC C'NC (I.) C , (IL) CS , (III.) S'C Members of the first series have not as yet been isolated . Derivatives of the second type have been obtained by A . Luchmann (Ben . 1896, 29, p . 1429) by condensing y-chlorbutylamine with carbon bisulphide or with mustard oils in the presence of caustic alkali; by M . Kahan (ibid., 1897, 30, p . 1321) on condensing bromhexylamine hydrobromide with thiobenzamide : CH2'CH(CH3)Br HS CH2'CH(CH3)'S (CH3)2C'N112 + HN:C'C6Hs (CHd)2C-N.seessesssC'C6Ii6 Benzothiazines are obtained from ortho-aminobenzyl halides and thio-amides : /CH2Br cm2' s Celli< +H2NCS'CHa--->C6H4c 1 \NNNH2 N—= 'CH3 . The most important thiazines are those derived from class III., thiodiphenylamine, C6H4\S>C6H4, being the parent substance of the methylene blue series of dyestuffs . Thiodiphenylamine is obtained synthetically by heating sulphur with diphenylamine miaire (5th October 1795) he opposed those Thermidorians who or by the condensation of ortho-aminothiophenol with pyro- wished to postpone the dissolution of the Convention . At the catechin . It is a compound of neutral reaction .

The first elections for the

Corps Legislatif he was elected by no less than known dyestuff of this series was Lauth's violet, which was thirty-two departments . It was only by the intervention of prepared by oxidizing paraphenylene diamine in acid solution Boulay de la Meurthe that he escaped transportation after the in the presence of sulphur . By using dimethyl paraphenylene coup d'etat of 18 Fructidor (4th September 1797), and he then diamine in place of the simple diamine, methylene blue is returned to the practice of his profession . The establishment obtained . The relationship of these substances to thiodiphenyl- of the consulate brought him back to public life . He was made amine was shown by A . Bernthsen, who, by nitration of prefect of the Gironde, and then member of the council of thiodiphenylamine, cbtained a dinitro-compound which on re- state, in which capacity he worked on the civil code . He at duction was converted into the corresponding di-amino-deriva- this time had Napoleon's confidence, and gave him wholetive and this on oxidation yielded Lauth's violet. hearted support .