NITROGEN BODIES OF MODERN CIIEMISTKY. 215 



to chloride of lime, called it ky auol, bl ue oil. Others have obtained it from 

 phenyl acid, from the beuzoate of ammonia; others again from indigo, 

 and these called it aniline, from the Indian name of indigo. Anil Indi- 

 gofera ; no one suspected that all these different bodies, produced in dif. 

 ferent ways, were identical, until their composition was studied, and after 

 numerous and varied experiments it was found that they were one and 

 the same pheuylamin. This base is obtained when we subject mirbauol 

 to the action of iron filings. The mirbauol is placed in a covered kettle 

 containing iron filings and water. The iron rusts ; thus by attracting the 

 oxygen, decomposing the water, and the nascent hydrogen from the 

 decomposed water, produces aniline from the mirbauol. This process 

 completed, the contents of the kettle arc distilled, and crude aniline 

 passes over. This requires repeated cleansing, and changes to manifold 

 colors. Kow, therefore, we find ourselves among the coloring substances. 



When aniline and arsenic acid are subjected for some hours to intense 

 heat, they are changed into a pitch-like, dark purple mass, which, on 

 beiug purified, yields crystallized Inch sin ; and if this red dye is dissolved 

 in an excess of aniline and the solution heated again in the same man- 

 ner, without suifering it to evaporate, it becomes a blue mass with a 

 coppery luster, (azuline.) If we add nitric acid to rose aniline, we obtain 

 aniline yellow and orange. If aniline is oxygenized with chromic acid, 

 chloric acid, and the salts of copper, we have gray and black ; if the sul- 

 phate of rose aniline is added to hyponitrite of natron, we obtain aniline 

 green. There is scarcely a color of the spectrum or of art which cannot 

 be produced from aniline. 



Aniline is the root of innumerable sliades of color, which are all of 

 marvelous beauty, but extremely i)erishable, not subject to chemical 

 influences, but whose chief enemy is the light; hence the exceeding 

 tendency to fade, of fabrics dyed with aniline. For this reason they are 

 suitable for those materials only which are soon worn out or soon out 

 of fashion; while durable fabrics ought never to be dyed with these 

 colors, since the light destroys them under all circumstances in a fabu- 

 lously short time. 



Aniline dyes have competitors. From the naphthaline of coal-tar — 

 this coal-champion — have similar bodies been produced, andnitro-naph- 

 thaline furnishes a whole series of colors, Vvhich, however, are of no 

 l)ractical interest. 



As the consumption of aniline dyes is enormous, efibrts are now in 

 progress to produce such modifications of them as will be soluble in 

 water or diluted nitric acid; because the original solvent, alcohol, or 

 wood-spirit, not only is too expensive, but also involves this evil, that 

 constant inhalation of alcoholic vapor produces injurious, sometimes 

 latal, effects on those who are subjected to it. 



When carbolic or phenic acid is mixed with fulminic acid, all three of 

 the hydrogen atoms at the other extreme of the chain are replaced by 

 uitryl, and thus is produced tri-nitrophenyl acid. This is probably the 



