452 NATURAL HISTORY. 



England : is the elektron of the Greeks. From its be- 

 coming electric by friction, it gave the name electricity 

 to science. Amber is used for many purposes : in the 

 form of beads for ornament ; for making varnishes ; in 

 Turkey is valued as mouth-pieces for their pipes, and is 

 burnt as incense in Romish churches. Copal is often 

 substituted in the place of amber in the making of var- 

 nish. Succmic acid, also called oil of amber, is also 

 made from it, and as heat is indispensable in the prepar- 

 ation of amber varnish, in order to fuse the amber, both 

 of these products are obtained at one time. 



Asphaltum Mineral Pitch is found either solid or 

 fluid ; in the latter form it is naptha. Asphaltum proper 

 occurs in solid, resinous masses, globular or reniform : color 

 pitch-black and brownish black ; opaque ; fracture bril- 

 liant, conchoidal; luster resinous. H. = 2.0. G. 

 1.1 to 1.2. Dissolves at heat corresponding with that 

 of water at boiling point, and burns with strong, bright 

 flame. Asphaltum is met with abundantly on the shores of 

 the Dead Sea, and in the Island of Trinidad, where it 

 occurs in huge solidified masses of black pitch, which look 

 like black rocks among the trees. Sometimes, but rarely, 

 asphaltum is found among marl and limestone, in Swit- 

 zerland, Hanover, and the Black Forest. Used in mak- 

 ing sealing-wax, varnishes, and for paving streets. 



THIRD ORDER. 

 BITUMINOUS R E S I X S . 



Rock-oil Naptha or Petrolium is a thin fluid, col- 

 orless or slightly yellow ; has a pitch-like odor, not at all 

 unpleasant; is very volatile and burns with a bright, 



