TRANSACTIONS OF SECTION B. 645 



The first gave CJI-OII and C^II.X ^ fj^^^^ ; the other C,H,OII and 



(c) Transposition with phenol. 



The first gave C,n,X = X-C,H,On and C,H5N~g2H5. the other 



C«H,X = X-Cyipn and aiLN^n'^^"- 



These experiments show certainly that the two compounds are different, and 

 different also from the product of reaction of ethylic iodide on diazoamido-toluene- 

 benzene. It is, however, not certain if this derivative is a third isomeride or a 

 mixture of the two described above. Mr. Meldola, on his side, has shown that 



there exist three different q'^h^ NO'^ i ^'^i^^-;'^^^^' 



6. On Methylene Blue and Methylene Red. By Professor Bernthsen. 



The author gave an account of his methylene blue and methylene red_ re- 

 searches. ' lie reported on the artificial production of Lauth's violet [thionine] 

 from thiodiphenykmine by nitration, reduction to diamidothiodiphenylamine, and 

 subsequent oxidation, forN^'arding the violet of the constitution 



CgH,— NIIj 

 N< > S 



I an,-Nii 



From the near relation between methylene blue and thionin the formula 



C,H3-N(CH3\, 



N< >S 



I C,H3-N(0H3),C1 



for the blue colouring matter was derived, and supported by experimental proof. 



A survey was given and diagi-ams were presented giving a review of the 

 details of the mentioned processes and over a number of other derivatives of 

 thiodiphenylamine. 



The author then passed to methylene red, a substance contained in the 

 mother liquors of methylene blue when prepared from ^-amidodimethyl- 

 aniline, sulphuretted hydrogen, and ferric chloride in acid solution. The red, 

 a well-defined crystalUne substance, readily soluble in water, is remarkable on 

 account of the high amount of sulphur contained in it. Proof was given that 

 it is represented by the formula OgllgNoS.^Cl. By reduction it produces a 

 most interesting substance, the mercaptane of amidodimethylanihne, Callia XgS,— 



N(OIl3X(4) 



C.H3AXH, (I) V 



^oll ' (2) 



a zinc salt of which can easily be isolated. Tliis, r.a an ortho-compound, gives 

 derivatives, as 



Cen.^N^c-cii3 '''^ ^^«^<f>N 



' Liebig's Annahn dcr Chemlr, Id. 220. 



