Any residue consists of black mercuric sulphide (and possibly white lead sulphate), in which mercury is confirmed by its usual tests.
In regard to the ancients' knowledge of lead compounds, we may state that the substance described by Dioscorides as, uoXv,3Saiva was undoubtedly litharge, that Pliny uses the word minium in its present sense of red lead, ana that white lead was well known to Geber in the 8th century.
Pliny mentions it under the name of minium, but it was confused with cinnabar and the red arsenic sulphide; Dioscorides mentions its preparation from white lead or lead carbonate.
A basic chloride, Pb(OH)Cl, was introduced in 1849 by Pattinson as a substitute for white lead.
It thus appears that white lead and sugar of lead were undifferentiated.
By the action of the acetic acid and atmospheric oxygen, the lead is converted superficially into a basic acetate, which is at once decomposed by the carbon dioxide, with formation of white lead and acetic acid, which latter then acts de novo.
After a month or so the plates are converted to a more or less considerable depth into crusts of white lead.
These are knocked off, ground up with water, freed from metal-particles by elutriation, and the paste of white lead is allowed to set and dry in small conical forms. The German method differs from the Dutch inasmuch as the lead is suspended in a large chamber heated by ordinary means, and there exposed to the simultaneous action of vapour of aqueous acetic acid and of carbon dioxide.
Venetian white, Hamburg white and Dutch white are mixtures of one part of white lead with one, two and three parts of barium sulphate respectively.
When carbon dioxide is passed into this solution the whole of the added oxide, and even part of the oxide of the normal salt, is precipitated as a basic carbonate chemically similar, but not quite equivalent as a pigment, to white lead.
It contains manufactories of chemicals, machinery, starch, white lead and various other articles, but is chiefly noted for its extensive salt springs and works, which produce about 75,000 tons of salt per annum.
A large trade is carried on at Burgdorf in the cheese of the Emmenthal, while among the industrial establishments are railway workis, and factories of cloth, white lead and tinfoil.
The same law prescribes conditions under which children between fourteen and eighteen years of age may be employed in the manufacture of white-lead, red-lead, paints, phosphorus, poisonous acids, tobacco or cigars, in mercantile establishments, stores, hotels, offices or in other places requiring protection to their health or safety; and it forbids the employment of boys under sixteen years of age or of girls under eighteen years of age in such factories or establishments more than ten hours a day (unless it be to prepare for a short day) or for more than fifty-eight hours to be chosen for the same term of service each voter shall vote for one only, and when three are to be chosen he shall vote for no more than two; candidates highest in vote shall be declared elected."
C. t has for its subject pavements and roads, their construction, mosaic floors; c. 2 is on white stucco for walls (opus albarium); c. 3 on concrete vaults, gypsum mouldings, stucco prepared for painting; c. 4 on building of hollow walls to keep out the damp, wall decoration by various processes; c. 5 on methods and styles of wall painting, the debased taste of his time; c. 6 on fine stucco made of pounded marble - three coats to receive wall paintings; c. 7 on colours used for mural decoration; c. 8 on red lead (minium) and mercury, and how to use the latter to extract the gold from wornout pieces of stuff or embroidery; c. 9 on the preparation of red lead and the method of encaustic painting with hot wax, finished by friction; cc. to-14 on artificial colours - black, blue, purple;, c. to white lead and ostrum, i.e.
There are numerous saw-mills, shipbuilding yards, engineering works, distilleries, sugar refineries, tobacco factories, linen bleacheries and stained glass, salt and white lead works.
As long as the solution contains lead, the addition of the molybdate solution causes a precipitation of white lead molybdate.
The manufactures comprise steel goods, mustard and vinegar, and a special kind of white lead (Kremser Weiss) is prepared from deposits in the neighbourhood.
The industrial establishments comprise white lead factories, machine and iron foundries, and commerce is active, especially in the mineral products of the region.
Chalk or white lead for the cheeks, ash or red ochre for the eyelids.
The hull was planked of selected teak with a double skin, with calico and white lead bedding between.
These had also been bedded down on white lead and thick tar or pitch to keep the area watertight with cork filling all voids.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.