220

DYEING AND CALICO PRINTING.

Rothine, or Phenicienne.

(Not to be confounded with phcenicine). This colour was discovered byRoth in 1863, and has“been prepared on a large scale at Mulhouse. It isobtained by pouring nitrosulphuric acid upon carbolic acid. The proportions are10 to 12 parts of the former to 1 of the latter. A small part of the nitro-sulphuricacid is added at first, and the rest is added in successive portions as the reactionceases, until no more orange vapours are given off on the last addition of acid.The whole is then thrown into a large quantity of water. An abundant brownprecipitate is immediately formed, which, when colledted, washed, and dried,is phenicienne. The washing is a tedious process, lasting several days. Thecolour is sparingly soluble in cold, and completely insoluble in hot, water;very soluble in ether, alcohol, and acetic acid, especially if a little tartaricacid has been added previously. Phenicienne is also readily soluble inalkaline liquids. It furnishes a great variety of solid shades, according tothe mordants employed. It resists sunlight, and even chloride of lime. Theshades which it yields surpass in purity and brightness all similar coloursobtained with the woods and orchil. It has certain analogies with catechu,and its shades are heightened in a similar manner by metallic salts capable ofexerting an oxidising adtion.

With silk and wool it is a substantive colour, the shades produced varyingfrom a deep garnet to a deep chamois, according to the concentration of thecolour-bath and the oxidising agents employed.

Cotton goods are previously mordanted with tannin and stannate of soda.Alkalies give the colour a blue cast, but the dye is then attacked by soap.

Phenicienne does not give satisfaftory results in printing, even on wool andsilk ; the process of steaming destroying its brilliancy.

Vesuvine.

This is a colour discovered by Knorp, of Stuttgardt. Its nature and pre-paration have not been closely described, but it is probably identical with thedye patened by Messrs. Roberts and Dale, as “ Manchester Brown,” and pro-duced by the B adtion of alkaline nitrites on phenylen-diamine. Vesuvine dyesorange and light brown shades. For use it is dissolved in tepid water andfiltered. This solution dyes wool and silk at the heat of 87° or 88° C. Theaddition of hyposulphite of soda to the extent of one-tenth the weight of thecolour is advantageous as regards wool. A variety of brilliant shades can beproduced by the addition of a solution of chloride of tin neutralised withammonia. Cotton tissues are first prepared with sumac ; then worked inweak stannate of soda, wrung out, passed through water slightly acidulatedwith sulphuric acid, rinsed in cold water, and worked in the dye-bath.

NAPHTHALIN COLOURS.

Naphthalin was discovered in coal-tar in 1820, and was first investigated byFaraday in 1826. Its percentage composition is—

Carbon. .g3 - 7

Hydrogen. 6-2

99’9

and its formula is C I0 Hs.