A Treatise on Calico Printing, VOL. I-II
Printed for C. O'Brien, Bookseller, Islington, and fold by Bew, Paternoster-row: Richardson, Royal Exchange: Murray, Fleet-Street: And the Booksellers of Manchester, Glasgow, Dublin, &c.
1792Namely, Regulus of Antimony, Bismuth, Zinc Regulus of Arsenic.
Reg. of antimony has the brilliancy, opacity, and gravity of a metal, but like all semi-metals, crumbles under the hammer: It soon dissipates into smoak and white vapours by a violent heat; flowers of antimony are those vapours, collected toy any cold body, which stops them in their ascension.
Its affinity is greatest with iron, copper next, and then with tin, lead, and silver.
Its proper solvent is aqua regia, marine acid next, if highly concentrated and applied by distillation; The vitriolic acid-likewise dissolves it, but with the nitrous it is little more than calcined.
Liver of antimony is procured by mixing nitre with it, three parts nitre and one of antimony produces a calx called diaphoretic antimony, or diaphoretic mineral. Antimony is used to separate gold from other metals, and the precipitate from its union with an alkali, is called the golden sulphur of antimony.
Bismuth.
This substance is rather duskier than the former, and like other semi-metals is volatized with a violent heat: It mixes with and quickens the fusion of all metals, whitens them, and destroys their malleability.
Bismuth is not soluble in the vitriolic acid, but in the nitrous it dissolves with much fume: Marine and aqua regia dissolve it, but with less rapidity; alkalies, and even water only, precipitate it, forming the magistery of bismuth. In its union with sulphur it forms a compound, appearing like needles lying sideways by each other.
Zinc.
Zinc differs little in appearance from bismuth, except having a bluish cast, though essentially it differs very much: It melts the moment it grows red, soon turning to a calx; and in an augmented heat burns like an oily matter, evincing the great quantity of phlogiston which it contains.
It unites with all metallic substances except Bismuth; It is soluble in all the acids, particularly in the nitrous; sulphur has little or no power over it.
It has a greater affinity with the vitriolic acid - than iron or copper has, forming a precipitate called white vitriol, or vitriol of zinc: United with copper it makes brass, pinchbeck, &c.
Regulus of Arsenic.
This readily unites with all metals, and is the most volatile of the semi-metals, flying off even by a moderate heat: the calx is plain arsenic; the properties of which are peculiar to itself, having great volatility, having a saline character, being soluble in water, and excessively corrosive, a quality none of the other semi-metals possess: It cannot be decompounded by any acid, except when joined to metallic substances: combined with the alkali of nitre or sea-salt, if they be in a fluid state, it forms a singular saline compound, called liver of arsenic: Arsenic unites readily with sulphur, and produces yellow orpiment.
Ei kommentteja :
Lähetä kommentti