56 Messrs. A. W. Hofmann and A. Geyger on [Dec. 5, 



In conclusion I may observe also that the secondary products of the 

 action of heat upon trimethylated phenylammonium iodide appear to be 

 of interest. A small fraction of the bases, generated at 335°, boils at a 

 very high temperature ; when allowed to stand for some time this frac- 

 tion deposits splendid crystals of a monamine which, according to the 

 analysis of the well-crystallized chlorhydrate and platinum salt, contains 



C U H 17 N; 



and the constitution of which, after a more minute examination, will 

 probably prove to be expressed by the formula 



[C„(CH 3 ) 5 ]H 2 N. 



Finally, there is found among these secondary products a beautifully 

 crystallized hydrocarbon, melting at 136°, and boiling between 230° and 

 240°. Some combustions of this body, which require confirmation, lead 

 to the simple formula 



C 4 H 6 , 



which determination of the gas volume weight will probably raise to 



C 12 H 18 = C 6 (CH 3 ) 6 . 



May this hydrocarbon actually be looked upon as sexmethylated 

 benzol ? If so, its oxidation promises results which will deserve minute 

 investigation. 



III. " Colouring-matters derived from Aromatic Azodiamines." 

 By A. W. Hofmann, Ph.D., F.R.S., and A. Geyger, Ph.D. 

 Received July 10, 1872. 



II. Safranine. 



Whilst we were engaged with the study of the blue colouring-matter 

 produced by the action of aromatic monamines on azodiphenyldiamine 

 our attention became directed to a beautiful red tar-pigment, which has 

 been known for some time by the commercial name of Safranine, being 

 extensively used as a substitute for safflower in dyeing silk and cotton. 

 Safranine has not as yet been minutely examined ; but, as far as can be 

 judged from the scanty information we possess regarding its production, 

 it is scarcely doubtful that this important dye must be looked upon as 

 being the derivative of an azodiamine. The analysis of safranine thus 

 promised to throw considerable light upon the nature of the compounds 

 under examination. 



The starting-point of our studies was the dye such as it occurs in com- 

 merce. The greater portion of it was supplied to us by Messrs. 

 Tillmanns, of Crefeld. Another specimen was received from Dr. J.Wolf, 

 and for a third one we are indebted to our friend M. Charles Girard, 

 of Paris. Both the first-mentioned specimens were assigned to us as 



