424 Scientific Intelligence. 
Azuline—This substance, which is a beautiful blue dye, has been intro- 
duced within the last six months. It was discovered by MM. Guinon, 
Marnas, and Bonney, of Lyons, who keep the process for its preparation 
asecret. It is obtained from coal-tar, but from which of its numer 
rior to Prussian blue. 
[The remarks of Mr. Perkin on the methods of applying coal-tar colors 
in the arts of dyeing and calico printing we omit, as all who are inter 
ested in the methods will seek fuller details in the dye-house——Eps 
and nitrophenylene diamine might be used for silk-dyeing, as its color 18 
ood and it stands the action of light well. Unfortunately, the chinoline 
colors, though very beautiful, are most fugitive. There has been an en 
eavor to introduce the chinoline blue of late; but, although a consider- 
able quantity of silk was dyed with it at first, it is now scarcely U - 
because, when exposed to the sun for two or three hours, the dyed SI 4 
becomes bleached. Aniline purple resists the light best. Fuchsine 4? d 
alpha aniline purple soon fade, especially when on cotton. © Azuline ant 
bleu de Paris are not easily acted upon by light when on silk. 
When the coloring matters of coal-tar were first introduced, there a 
a great fear that the workmen engaged in their manufacture would su . 
in health. All I can say is that, during the few years I have ad 
with this branch of manufacture, there has not been a single case 
illness among the workmen that has been produced by any operations 
carried on for the production of aniline purple. 5s t 
[Wote.—To the reader desirous of consulting a more detailed accoun 
of “the Coloring Matters derived from Coal-Tar” than is contained a 
Mr. Perkin’s instructive lecture, we would commend a series of pape 
Sur la Préparation des matizres colorantes artificielles, by Prof. Emile 
