Arsenic, in its well-known and beautiful forms, orpiment and realgar, is found in New South Wales and Victoria.
Chaucer, Chanouns Yemannes Tale, where, however, mercury figures both as a spirit and a body: " The firste spirit quik-silver called is, The second orpiment, the thridde ywis Sal armoniak, and the ferthe brimstoon."
Many substances were employed in ancient medicine: galena was the basis of a valuable Egyptian cosmetic and drug; the arsenic sulphides, realgar and orpiment, litharge, alum, saltpetre, iron rust were also used.
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.
Lead, copper, sulphur, orpiment, also lignite, have been found within the confines of the province; also a kind of beautiful, variegated, translucent marble, which takes a high polish, is used in the construction of palatial buildings, tanks, baths, &c., and is known as Maragha, or Tabriz marble.
Cinnabar, realgar, orpiment and coal form the rest of the mineral products of Kwei-chow.
A., 1884, p. 93); several copper mines in Khorasan, Samnan, Azerbaijan and Kerman; some of lead, two considerably argentiferous, in Khorasan, Tudarvar (near Samnan), Anguran, Afshar (both west of Zenjan), and Kerman; two of iron at Mesula in Gilan and Nur in Mazandaran; two of orpiment in Afshar and near Urmia; one of cobalt at Kamsar (near Kashan); one of alum in Tarom (near Kazvin); and a number of coal in the Lar district, north-east of Teheran, and at Hiv and Abyek, north-west of Teheran.
ORPIMENT (auripigmentum), arsenic trisulphide, As2S3, or yellow realgar, occurring in small quantities as a mineral crystallizing in the rhombic system and of a brilliant goldenyellow colour in Bohemia, Peru, &c. For industrial purposes an artificial orpiment is manufactured by subliming one part of sulphur with two of arsenic trioxide.
Formerly, under the name of "king's yellow," a preparation of orpiment was in considerable use as a pigment, but now it has been largely superseded by chrome-yellow.
Arsenic is a constituent of the minerals arsenical iron, arsenical pyrites or mispickel, tin-white cobalt or smaltite, arsenical nickel, realgar, orpiment, pharmacolite and cobalt bloom, whilst it is also met with in small quantities in nearly all specimens of iron pyrites.
There are three known compounds of arsenic and sulphur, namely, realgar As2S2, orpiment As2S3, and arsenic pentasulphide As2S5.
Orpiment (auri pigmentum) occurs native in pale yellow rhombic prisms, and can be obtained in the amorphous form by passing a current of sulphuretted hydrogen gas through a solution of arsenious oxide or an arsenite, previously acidified with dilute hydrochloric acid.
Arsenic pentasulphide,As2S5, can be prepared by fusing the trisulphide with the requisite amount of sulphur; it is a yellow easily-fusible solid, which in absence of air can be sublimed unchanged; it is soluble in solutions of the caustic alkalis, forming thioarsenates, which can also be obtained by the action of alkali polysulphides on orpiment.
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 140Ã‚° 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.
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