On Silicium and Zirconium. 157 



during evaporation it thickens, coagulates, and deposits portions 

 of the earth, in the form of gummy transparent masses. The siii- 

 ciuret of potassium, heated with sulphur, burns vividly, and when 

 dissolved leaves the pure silicium. Silicium takes fire in chlorine 

 at a red heat, and a liquid results, colourless, or of a light-yellow 

 colour, of an odour resembling that of cyanogen, very volatile, 

 and which, with water, congeals, and deposits gelatinous silica. 

 I have not as yet examined its conducting power for electricity 

 and heat, its specific gravity, &c. 



" Nothing is easier than to procure this substance ; the follow- 

 ing is the mode I have ultimately adopted : The double fluate of 

 silica with potash or soda, heated almost to redness to drive off 

 hygrometric water, is introduced into a glass tube, closed at one 

 extremity ; pieces of potassium are then to be introduced, and the 

 metal carefully mixed with the powder, by heating it till it fuses, 

 and then lightly striking the tube. It is then to be farther heated 

 by a lamp, and before it attains a red heat there is a slight deto- 

 nation, and the silicium is reduced. The mass is to be cooled, 

 and then washed witli water as long as anything dissolves. There 

 is at first disengagement of hydrogen gas, because a portion of 

 siliciuret of potassium has been formed, which cannot exist in 

 contact with water. The washed substance is a hydruret of sili- 

 cium, which at a red heat burns vividly in oxygen gas, although 

 the silicium is not completely oxidized ; it is to be heated in a 

 covered platinum crucible, slowly augmenting the fire to redness ; 

 the hydrogen only oxidizes, and the silicium will no longer burn 

 in oxygen gas ; though chlorine attacks it very easily. The little 

 silica produced may be removed by tluoric acid, but if the silicium 

 has not been strongly heated, the acid will dissolve a little of it, 

 with the disengagement of hydrogen. According to the synthetical 

 experim.ents which I have made, silica contains about 0.52 of its 

 weight of oxygen. 



" Zirconium is obtained in an analogous manner. It is as black 

 as carbon, does not oxidate in water or in muriatic acid, but nitro- 

 muriatic and fluoric acids dissolve it, the last with the disengage- 

 ment of hydrogen. At a temperature but slightly elevated it 

 burns with great intensity. It combines with sulphur. Its sulphu- 

 ret is of a chestnut-brown colour like silicium, and insoluble in 

 muriatic acid or tiie alkalis. It burns with brilliancy, producing 

 sulphurous acid gas and zirconia." — Ann. de Chim. xxvi. 41. 



V. Division of a Right Line, by M. Vouuz. 



The following new geometrical process for the division of aright 

 line into any number of equal parts is by M. Voruz, Principal of 

 the College of Moudon, Canton de Vaud, who, in his letter to the 

 editors of the Bib. Univ. says, that although the subject is very 



