PERKIN'S VIOLET , OR MAUVE.

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means of a glass rod and applied to a piece of white blotting-paper. Ifmore than one colouring matter is present the different shades will diffusethemselves in concentric circles and may be distinctly seen. This method isstill more applicable to the aniline violets and blues, which are frequentlyheterogeneous.

Aniline Crimson.

The crude magenta-cake without any purification is sold under this name,and is used in dyeing certain maroons, browns, clarets, and other compoundcolours.

The colour, well bruised or broken up into powder, is placed in a suitablestoneware vessel and well stirred up with its own weight of hydrochloric acid.During this process the fumes given off should be carefully avoided. After thecolour has steeped for a short time in the acid, boiling water is added sufficientto dissolve the whole. The solution thus obtained is carefully strained, and isthen ready for use. To correct the acidity of the colour a small quantity ofammonia is added to the dye-bath. This preparation will in many casessupersede peachwood, producing brighter shades, with less trouble, and at alower price. They are, however, more fugitive. Upon wool and silk anilinecrimson, like magenta, is a substantive colour. Upon vegetable fibres it requiresto be fixed with a mordant—generally a per-salt of tin—and an astringent.

Ponceau.

This is the trade name of an aniline colour manufactured by the eminentfirm of Brooke, Simpson, and Spiller (late Simpson, Maule, and Nicholson).The process by which it is obtained is secret. The colour is redder than thereddest shade of roseine, appears exceedingly bright by artificial light, and isconsidered faster than the magentas. It is a substantive colour on wool andsilk, the only precaution required in dyeing being to add the colour verygradually to the neutral bath, and work slowly up to the required shade. Noprevious mordanting or other preparation is necessary. The tone can, ifneeded, be varied by the addition of a little ammonia.

The aniline violets include a formidable list of colours, unlike in theirpreparation, constitution, and properties, and sold under such names asmauve, harmaline, parma, dahlia, primula, indisine, rosolane, violine, phe-nameine, &c.

Perkin’s Violet, or Mauve.

The earliest aniline colour introduced into commerce has lost muchof its importance. Runge had previously called attention to the violetcolouration produced on treating aniline with chromic acid or the hypochlorites.In August, 1856, Mr. Perkin patented his process for the produ&ion of a violetcolouring matter from aniline.

The production of this violet or mauve colour depends upon the action ofoxidising agents upon aqueous solutions of salts of commercial aniline. Theviolet or mauve of commerce contains a powerful organic base now calledMauveine, soluble in alcohol, with a dingy violet colour. The development ofthe mauve is the result of the union of this base with an acid. The colouringmatter generally used is the acetate of mauveine, a salt which may be obtainedin fine crystals of a green metallic lustre. Mauveine has so great an affinity