218 ANNUAL OF SCIENTIFIC DISCOVERY. 



struck, emitted the finest tones, such as are obtained only by a combination 

 of the best metals. 



PREPARATION OF METALLIC LITHIUM. 



Bunsen has continued his observations on the alkaline and earthy metals, 

 and has succeeded in isolating lithium upon a sufficiently large scale to admit 

 of an accurate determination of its chemical and physical properties. Lithium 

 is more easily prepared than the other metals belonging to the same class, and 

 its separation forms an easy and certain lecture-room experiment. Chloride 

 of lithium is to be fused in a small thick porcelain crucible over a Berzelius 

 lamp, and decomposed by a current of from 4 to 6 Bunsen's elements. The 

 current passes from a point of gas-carbon through the fused chloride to an iron 

 wire as thick as a knitting-needle. After a few seconds a small silver white 

 regulus forms and adheres to the wire, gaining in a few minutes the size of a 

 small pea. The mass is to be removed from the fused chloride by passing 

 under it a small iron spoon, and withdrawing the spoon and the wire electrode 

 together so that the metal shall remain covered with a varnish of the fused 

 chloride. The spoon is then to be cooled under naptha, and the metal scraped 

 off with a penknife. As these operations may be repeated every three min- 

 utes, an ounce of chloride of lithium may be reduced in a short time. Lithium 

 is a white metal having the color of silver, but a freshly cut surface soon be- 

 comes yellowish from oxy elation. Fused at 180, and quickly pressed up be- 

 tween two glass surfaces, lithium gives a mirror which perfectly resembles 

 polished silver in color and luster. Its streak is gray, while that of calcium, 

 barium, or strontium is yellow. Lithium is also a very tough metal, and can 

 easily be drawn to a wire like lead, but its tenacity is much less than that of 

 the latter metal. Lithium fuses at 180, is not volatile at a red heat, and can 

 be welded at ordinary temperatures. Its density is 0.5936, and it is the lightest 

 of all solid bodies. If we take its equivalent at 81.7 (0=100) its atomic vol- 

 ume is 1 3 7 . It is less oxydizable than potassium or sodium takes fire at a tem- 

 perature far above 180 Centigrade, and burns quietly without sparks, and with 

 a white and unusually dense light. The elevation of temperature is here so 

 great that a piece of lithium weighing only 0.005 qr. will melt a hole of 36 

 millimeters in a piece of mica, upon which it moves with a serpentine motion. 

 Strontium and calcium burn in a similar manner with a yellowish light, how- 

 ever, and not so quietly, but with sparks and a hissing noise. Lithium burns 

 in oxygen, chlorine, bromine, carbonic acid, vapor of iodine, and upon fused 

 sulphur, like calcium and strontium, with extraordinary brilliancy and intense 

 white light. Upon water lithium floats and oxydizes like sodium, but without 

 fusing. Silica glass and porcelain are reduced by lithium under 200 Centi- 

 grade, but by calcium and strontium only at a red-heat. Calcium and stron- 

 tium are not white metals, as has been stated, but show under the polishing 

 steel, as well as when reduced to a red-heat and freshly cut, a beautiful gold 

 yellow color. Ann. der Chemie und Pharmacie, 1855, sciv. 



