Another very excellent method of vulcanizing cut sheet goods consists in placing them in a solution of the polysulphides of calcium at a temperature of 140° C. Rubber employed for the manufacture of cut sheets is often coloured by such pigments as vermilion, oxide of chromium, ultramarine, orpiment, antimony, lamp black, or oxide of zinc, incorporation being effected either by means of the masticator or by a pair of rollers heated internally by steam, and so geared as to move in contrary directions at unequal FIG.
This species from the high north of Europe and Asia carries green eggs, and above them a bright pattern in ultramarine (Sars, 1896, 1897).
In 1828 he was awarded the prize offered by the Societe d'Encouragement pour l'Industrie Nationale for a process of making artificial ultramarine with all the properties of the substance prepared from lapis lazuli; and six years later he resigned his official position in order to devote himself to the commercial production of that material, a factory for which he established at Fleurieux sur Saone.
Chaptal for a cheap colouring matter, as bright as ultramarine and capable of standing the heat of the porcelain furnace.
Now, however, the mottled soaps, blue and grey, are produced by working colouring matter, ultramarine for blue, and manganese dioxide for grey, into the soap in the frame, and mottling is very far from being a certificate of excellence of quality.
ULTRAMARINE, a blue pigment, consisting essentially of a double silicate of aluminium and sodium with some sulphides or sulphates, and occurring in nature as a proximate component of lapis lazuli.
In 1814 Tassaert observed the spontaneous formation of a blue compound, very similar to ultramarine, if not identical with it, in a soda-furnace at St Gobain, which caused the Societe pour l'Encouragement d'Industrie to offer, in 1824, a prize for the artificial production of the precious colour.
Processes were devised by Guimet (1826) and by Christian Gmelin (1828), then professor of chemistry in Tubingen; but while Guimet kept his process a secret Gmelin published his, and thus became the originator of the "artificial ultramarine" industry.
"Ultramarine poor in silica" is obtained by fusing a mixture of soft clay, sodium sulphate, charcoal, soda and sulphur.
The product is at first white, but soon turns green ("green ultramarine") when it is mixed with sulphur and heated.
Artificial, like natural, ultramarine has a magnificent blue colour, which is not affected by light nor by contact with oil or lime as used in painting.
Ultramarine being very cheap, it is largely used for wall painting, the printing of paperhangings and calico, &c., and also as a corrective for the yellowish tinge often present in things meant to be white, such as linen, paper, &c. Large quantities are used in the manufacture of paper, and especially for producing that kind of pale blue writing paper which is so popular in Great Britain.
By treating blue ultramarine with silver nitrate solution, "silverultramarine" is obtained as a yellow powder.
This compound gives a blue potassiumand lithium-ultramarine when treated with the corresponding chloride, and an ethyl-ultramarine when treated with ethyl icdide.
Seleniumand tellurium-ultramarine, in which these elements replace the sulphur, have also been prepared.
It has been suggested that ultramarine is a compound of a sodium aluminium silicate and sodium sulphide.
In a deep-coloured stone the colour may be resolved, by the dichroscope, into an ultramarine 1 Indirectly from Gr.
5 a treasury was deeply indebted, had a capital of £1,500,000, and a monopoly of note issue in continental Portugal, but the notes of the Ultramarine Bank circulated in the colonies.
"Ultramarine rich in silica" is generally obtained by heating a mixture of pure clay, very fine white sand, sulphur and charcoal in a muffle-furnace.