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THE ANILINE DYES. 
BY DR T. L. PHIPSON, F.O.S., 
LxVTE OF THE UNIVERSITY OF BRUSSELS, MEMBER OF THE CHEMICAL 
SOCIETY OF PARIS, &C. &C. 
I T has been whispered to me that a popular history of the 
new Aniline Dyes would fill a gap that has hitherto re- 
mained wide open in the scientific literature of the present 
day. In taking up my pen to compose such a history, I would 
be allowed to remark, by way of preface, that the following 
lines are not intended for the philosophical transactions and 
the aristocrats of science, but for the Popular Science Review 
and the Garibaldians of philosophy. In all matters connected 
with chemistry it is best to be as brief as is consistent with 
explicitness, and to avoid anything approaching to grand 
phrases or “ sensationism therefore I shall offer no apologies 
for roughness of style or for attacking the subject in a straight- 
forward manner. 
As the only thing I happen to have done myself in con- 
nection with aniline was the discovery of this curious com- 
pound in the vegetable world, I shall take Dr. Hofmann in my 
right hand and Messrs. Simpson, Maule, & Nicholson in my 
left, combining theory and practice, whilst travelling over one 
or two of the most beautiful and luxuriant pages of modern 
chemistry. 
It may seem wonderful that, to arrive at the brilliant colours 
which serve to illustrate this paper, we must start from coal ; 
for it is among the products of the distillation of coal that 
we find the substances capable of yielding these magnificent 
dyes. In ordinary language the word distillation applies to 
liquids only, but in chemistry it is equally applicable to any 
substance which, being placed in a close vessel and heated, 
gives off vapours which distil. Now, if instead of water or 
spirit we put a solid piece of coal into a retort and apply heat, 
the following phenomena invariably occur : a considerable 
amount of combustible gas is evolved ; this is no other than the 
gas which lights our streets, and whilst it is produced a large 
amount of tar and watery vapour distils and passes out of the 
retort. When the operation is finished, that is, when no more 
VOL. in. — NO. XII. 2 G 
