ALBBETITE 41 



of Salzburg and Austria, contain sand veins and hard nodulos, aud require to be 

 quarried by cleaving and blasting operations, -which are apt to crack it and render it 

 unfit for all delicate objects of sculpture. It is, besides, of a grey shade, and often 

 stained with darker colours. 



The alabaster best adapted for the fine arts is white -when newly broken, and becomes 

 yet whiter on the surface by drying. It may be easily cut with the knife or chisel, 

 and formed into many pleasing shapes by suitable steel tools. It is worked either 

 by the hand alone, or with the aid of a turning-lathe. The turning tools should not 

 be too thin or sharp-edged ; but such as are employed for ivory and brass are 

 most suitable for alabaster, and are chiefly used to shave and to scratch the surface. 

 The objects which cannot be turned may be fashioned by the rasping tools, or with 

 minute files. Fine chisels and graving tools are also used for the better pieces 

 of statuary. 



For polishing such works, a peculiar process is required : pumice-stone, in fine 

 powder, serves to smooth down the surfaces very well, but it soils the whiteness of 

 the alabaster. To take away the unevenness and roughness, dried shave-grass 

 (equisetum) answers best. Friction with this plant and water polishes down the aspe- 

 rities left by the chisel : the fine streaks left by the grass may be removed by rubbing 

 the pieces with slaked lime, finely pulverised, sifted, and made into a paste : or with 

 putty-powder (oxide of tin) and water. The polish and satin-lustre of the surface are 

 communicated by friction, first with soap-water and lime, and finally with powdered 

 and elutriated talc or French chalk. 



Such articles as consist of several pieces are joined by a cement composed of quick- 

 lime and white of egg, or of well-calcined and well-sifted Paris plaster, mixed with 

 the, least possible quantity of water. 



Alabaster objects are liable to become yellow by keeping, and are especially 

 injured by smoke, dust, &c. They may be in some measure restored by washing 

 with soap and water, then with clear water, and again polished with shave-grass. 

 Grease-spots may be removed either by rubbing with talc powder, or with oil of 

 turpentine. 



The surface of alabaster may be etched by covering over the parts that are not to 

 be touched with a solution of wax in oil of turpentine, thickened with white lead, 

 and immersing the articles in pure water after the varnish has set. The action of 

 the water is continued from 20 to 50 hours, more or less, according to the depth to 

 which the etching is to be cut. After removing the varnish with oil of turpentine, 

 the etched places, which are necessarily deprived of their polish, should be rubbed 

 with a brush dipped in finely-powdered gypsum, which gives a kind of opacity, con- 

 trasting well with the rest of the surface. 



Alabaster may be stained either with metallic solutions, with spirituous tinctures of 

 dyeing plants, or with coloured oils, in the same way as marbles. 



ALABASTER, ORIENTAIi. Oriental alabaster is a form of stalagmitic or 

 stalactitic carbonate of lime, an Egyptian variety of which is highly esteemed. It is 

 also procured from the Pyrenees, from Chili, and from parts of the United States of 

 America. Ancient quarries are still in existence in the province of Oran, in Algeria. 

 The well-known 'Gibraltar stone' and the Californian marble are similar sta- 

 lagmitic forms of carbonate of lime. This Oriental alabaster, or alabaster of the 

 ancients, is to be carefully distinguished from the mineral now commonly known as 

 alabaster ; the former is a carbonate, the latter a sulphate of lime. See Omrx, 

 ALGERIAN. 



AXiBAN. A white resinous substance extracted from gutta-percha by either 

 alcohol or ether. See GUTTA-PERCHA. 



AXiBAlTX STONE. (Lapis albanus). The Peperino of modern geologists. A 

 dark volcanic tufa found in Italy, much used at Rome before building with marble 

 became common. The Italian name pcperino is derived from pepe, pepper, which it 

 somewhat resembles. 



AliB AT A PXiATE, a name given to one of the varieties of white metal now so 

 commonly employed. See COPPER and AIXOYS. 



AliBERTITE. A jet-black mineral substance resembling asphalt, discovered in 

 1849 at Hillsborough, in Albert Co., New Brunswick. It occurs in irregular fissures 

 in Lower Carboniferous rocks, and is now usually regarded as the residue left on the 

 drying-up of a great body of petroleum. ' The deposit of the Albert mine would thus 

 be a vein or fissure constituting an ancient reservoir of petroleum, which, by the loss 

 of its more volatile parts and partial oxidation, has been hardened into a coaly 

 substance.' (Dawson). Albertite has been largely used in the United States for the 

 distillation of oil and coke. The yield per ton is said to bo 100 (crude) gallons of 

 oil, and 14,500 cubic feet of illuminating gas, while a residue of good coke remains in 

 the retorts. 



