PURPLE DYEING, ANCIENT AND MODERN. 399 



strong soapsuds and the purple becomes a magnificent and permanent crimson. 

 Dyed with this singular fluid the fobric passes throiigh all the prismatic changes 

 of color of which we have spoken, in a very few minutes ; and if exposed to heat 

 as well as light, the changes are so rapidly effected that the eye can scarcely 

 appreciate the passing of one hue into another ; but if, on the contrary, light 

 be completely excluded, the first pale, yellowish green will remain^ unchanged 

 for years. Bancroft proved this with some linen thus dyed, and kept for nine 

 years in the dark. 



As to the causes of the changes of color they arc not clearly understood. 

 Bcrthollet thinks that the coloring matter absorbs oxygen. Bancroft attributes 

 the effect to light. lie justifies his opinion by reference to the coloring of prints, 

 flowers, &c., Avhich coloring is known to take place, not from wai-mth, but from 

 light. It is by the mere exclusion of light that we bleach, for instance, endive 

 and celery. 



As far as we arc at present informed, the chemical nature of this coloring 

 matter is as little known as the modua operandi of its successive changes afrer 

 being applied to a textile material. Highly as Bancroft and others have praised 

 the purple, it has had its day of popular favor. For dyeing fine muslins, and 

 as a marking fluid, purple is still occasionally used. Even as long ago as the 

 thirteenth century, scarlet, from Kcrmes, instead of purple, was the adopted 

 color of the Hungarian magnates. Our numerous dyestuffs, and our facile and 

 economical dyeing processes, render us independent of the ancient purple. 



With the revival of science and art from the decadence into Avhich tliey had 

 sunk,, during wha^ are not unjustly called the dark ages, dyeing, like other arts, 

 started into new, vigorous life. Till the fifteenth century, and still later, Italy 

 bore away the palm in the art of dyeing, for which Florence and Venice were 

 especially renowned. The discoA'ery of America gave a great impulse to the 

 Siime art, dyestuflTs being furnished which were entirely unknown to the Flora 

 and the Fauna of the Old World. From the Italians the mastery in the art 

 passed to the Flemings ; and when the religious persecutions by Spain drove 

 the Flemings into exile, these latter carried their art into France and England. 

 It was a native of the Netherlands, Cornelias Drebbel, by whom, in 1650, the 

 discovery was made that cochineal Avas capable of yielding a dye f;\r surpassing 

 iu beauty the purple of the ancients. Drebbel was at work in his laboratory, 

 when an accident having thrown some aqua rcga over the tin fastenings of the 

 window panes, and thence into a bottle full of an aq^ueous infusion of cochineal, 

 the latter on the instant assumed that magnificent scarlet tint which is now 

 so well known. Drebbel was too acute and too reflecting an observer to neglect 

 such an indication, and from that time cochineal has played an important part 

 in the art of dyeing. 



]\Iodern chemistry, however, has done more for this art in single years than 

 had previously been accomplished in centuries. Pure and eficctive mordants 

 and mineral colors have wonderfully changed both the laborious and the eco- 

 nomical processes of the art. Colored garments were formerly the external sign 

 of rank or opulence. At the pi-csent day, thanks to the labors of men of science, 

 the man who wears the homeliest and cheapest garb, as to quality of fabric, may 

 yet wear it of the most tasteful color. Chemistry, however, is still making and 

 will lon<^ continue to make still further improvements in this art, as in others. 

 One of tlie latest acquisitions thus made by the secluded men of the laboratory 

 15 that of the much-valued coloring material known as 



MUREXl.NE, (MUREXIDROTH.) 



This color is extracted from the uretric acid contained in urine. 

 The ancient adepts, or alchemists; carefully analysed that fluid, in which in- 

 deed they sought thcii- arcanum, and iu the course of their expcrimeutiug they 



