ELVANITE 253 



powder will be collected in the next vessel ; and by repeating this process an im- 

 palpable powder may bo obtained. This process is called Eleutriation. 



ELEVATORS FOR 2VLIUES. Under this name Messrs. Alexander Alison 

 and John Shaw have patented an arrangement for ' Raising water and minerals from 

 collieries and mines, and for other purposes.' There is much ingenuity in the arrange- 

 ments proposed, which are in point of fact modifications of the systems adopted by 

 the Pneumatic Despatch Company. The principle involved will be sufficiently under- 

 stood from the following description, taken from the Specifications of the patentees : 

 A cylinder or tube is placed in the shaft which rises a few feet above the top of it, 

 and reaches, to a few feet below the bottom of the mine; this cylinder is made of 

 malleable or cast iron, or other suitable metal or material, and of a diameter accord- 

 ing to the weight of minerals, water, or other substances to be lifted. In this cylinder 

 or tube a double-headed piston works, and between the two heads of the piston a fixed 

 or moveable receiver, or barrel, or waggon is placed, which holds the mineral or water 

 to be raised. 



An air-pump worked by a steam-engine or water-wheel, or other power, is used for 

 forcing air down the shaft in a tube, which air passes into the cylinder below the 

 under piston head. Forcing only may be used, but exhausting and forcing may be 

 used in conjunction. When the load is put in at the bottom, a valve is opened so that 

 the air is introduced under the piston, which with its load then rises to the top ; on 

 arriving at the top the load is removed, and on an escape-valve at bottom being 

 opened, the piston descends, and the air which escapes ventilates the mine. This 

 elevator not only acts as an elevator and ventilator, but provides a safe and expedi- 

 tious mode of conveying workmen up and down the shaft. 



The other improved elevator maybe described thus : Air is forced by an air-pump, 

 worked by steam or other power, down a tube into one or more cisterns in the bottom 

 of the shaft, into which the water of the mine runs. The water is in this way forced 

 up to the surface through another tube. The cistern or cisterns are fitted with self- 

 acting valves, which open and shut by means of a float. As the air escapes from the 

 bottom this elevator acts as a ventilator as effectually as the one previously described* 

 See MAN-ENGINE. 



ELXASITE. An ore of uranium. A mineral allied to pitchblende, but differing 

 from it widely in its large proportion of water and lower specific gravity (4*086 

 to 4-237). 



It occurs with fluor, dolomite, quartz, &c., at the Elias mine, Joachimstal (whence 

 its name), in large flattened pieces, sometimes half an inch thick, of a dull reddish- 

 brown colour, approaching to hyacinth-red on the edges. 



It is subtranslucent, with a greasy subvitreous lustre, and affords a dull streak, 

 varying from wax-yellow to orange. Hardness between calcite and fluor spar. 



It is composed of peroxide of uranium, 6T33 ; alumina, 1*17; peroxide of iron, 

 6'63 ; protoxide of iron, 1-09 ; lime, 3'09 ; magnesia, 2*20 ; oxide of lead, 4-62 ; 

 silica, 5'13; carbonic acid, 2'52; phosphoric acid, 0*84; water, 10 - 68: Total, 99'30. 



Before the blowpipe it affords a reaction like pitchblende; it is decomposed by 

 muriatic acid. H.W.B. 



IE LIQUATION. The separation of lead and silver from ' copper, the agent for 

 doing this being lead. The copper containing silver was melted with a certain portion 

 of lead, and cast into discs. These discs were exposed to a temperature sufficiently 

 high to melt the lead. This metal then liquated, or separated from the copper, carry- 

 ing the greater portion of the silver with it. The process is seldom now employed. 



ELIXIR OP VITRIOL. A preparation of sulphuric acid, with some aromatics. 



ELM. ( Ulmus, Lat. ; Orme, Fr. ; Ulme, Ger.) Of this European timber tree 

 there are five species. The Ulmus campestris, the English Elm, is regarded in this 

 country as one of the finest of European deciduous trees for park scenery ; it lives 

 for upwards of 200 years, forming a remarkably straight tall trunk. The quality 

 of timber depends a good deal on the soil in which it is grown, being always best on 

 a dry, loamy soil, with plenty of air. The Ulmus montana, is the Mountain, Scotch, 

 or Wych Elm: the trunk is not so lofty nor the wood so heavy as the English 

 Elm; and though coarse-grained, is very highly prized by shipbuilders and cart- 

 wrights. It possesses great longitudinal adhesion, and is consequently one of our 

 stiffest and straightest timbers. These woods are not liable to split ; they bear the 

 driving of nails or bolts better than any other timber, and are exceedingly durable 

 when constantly wet. They are therefore much used for the keels of vessels, 

 and for wet foundations, waterworks, piles, pumps, and boards for coffins. On 

 account of its toughness, it is selected for the naves of wheels, and for the gunwales 

 of ships. 



ElVAWXTE. A quartziferous porphyry, forming the typical rock of the Cornish 

 Elvans. 



