The Engineer's and Mechanics Encyclopædia: Kermes-Mineral.

The Engineer's and Mechanics Encyclopædia,
comprehending practical illustrations of the machinery and processes employed in every description of manufacture of the British Empire.
With nearly Two Thousand Engravings.
By Luke Hebert, civil engineer, edifor of the History and Progress of the Steam Engines, Register of Arts and Journal of Patent Inventions, etc.
In two volumes.
London: Thomas Kelly, 17, Paternoster Row.
Kermes-mineral is usually prepared by 1 pound of common antimony with 22½ lbs. of the sub-carbonate of potash, and 20 gallons of water in an iron pot, filtering the liquor whilst hot into earthen pans, and letting it cool slowly for 24 hours, the kermes-mineral is deposited in the form of a powder ot a deep purple brown colour. The supernatant liquid, which yields an orange coloured sediment, called the golden sulphur of antimony, is much used by the calico printers in the following manner: — They evaporate and crystallize the supernatant liquor; the crystals are then dissolved in fresh water, and with this solution, thickened with starch or gum, they print their cloths; the cloths after being dried, are passed through a weak acid liquor, which separates the golden sulphur and fixes it on the cloth. M. Fabrom states that a much finer kermes-mineral may be obtained by employing tartar in lieu of the alkali in the usual process. Three or four parts of the tartar are to be mixed with one part of powdered sulphuret of antimony, and exposed to a red heat in a crucible, until the entire decomposition of the tartar is indicated by the cessation of fumes; the mass should then be dissolved in warm water, be filtered, and left to cool, when an abundance of very fine deep coloured kermes will be deposited in the bottom of the vessel. This abundance of the kermes is, however, not attended with any diminution of the quantity or brilliancy of the golden sulphuret subsequently obtained by the addition of acid to the mother liquor.

Ei kommentteja :