CHEMICAL SCIENCE. 213 



the small crust. The globules are crushed in a mortar, and the flattened 

 granules are then picked out. 



It may also be obtained in very small granules, but with more difficulty, by 

 just touching the surface of the fused mass of chlorides for a minute or two 

 with the tip of the wire, so that the action of the current produces a sort of 

 appearance of fermentation. The globules are rather larger than when the 

 point of the wire is immersed and withdrawn until an electrical flame makes 

 its appearance. By this means an alternate heating and cooling is produced 

 by which the pulverulent metal is fused together. 



Properties of Calcium. The properties of the metal prepared in the above 

 manner are as follows. Some of them have hitherto not been correctly recog- 

 nized: 



It is a pale yellow metal, of the color of bell-metal, or of silver alloyed 

 with gold. Freshly filled spots appear paler and remarkably glittering. 

 Fracture-jagged, becoming granular, it is very ductile, and may be cut, bored, 

 or filed. A piece of the size of a mustard-seed could be beaten out to a leaf 

 of 10 or 15 millims., and then only show a few breaks at the margin. In 

 dry air it remains shining, but soon tarnishes in a moist atmosphere. It melts 

 at a red heat on platinum foil, and then burns with a splendid luster, so that 

 pieces of the quarter the size of a pin's head give a ball of fire of a cubic inch 

 in size. Calcium filings thrown into the flame of a spirit-lamp give beautiful 

 stellate sparks. Dry chlorine has but little action upon it ; when heated in 

 chlorine gas, or in vapor of iodine or bromine, it burns with bright incandes- 

 cence. When thrown upon boiling sulphur, it combines with it, with violent 

 evolution of flame. It combines with vapor of phosphorus, without incandes- 

 cence, forming phosphuret of calcium. With hot mercury it readily forms a 

 white amalgam. It violently decomposes water, becoming converted into 

 hydrate of lime. Dilute nitric, muriatic, and sulphuric acids facilitate the 

 oxydation. Thin laminae frequently become ignited under the surface of dilute 

 nitric acid ; in concentrated nitric acid it retains its bright surface, and is only 

 attacked at a boiling heat. With distilled water as the- exciting fluid, it be- 

 haves negatively with potassium and sodium, positirely with magnesium. It 

 is not, however, reduced from its chloride by potassium or sodium. LieUg's 

 Anncden, xciii. p. 277. 



OX SILICIUM AXD TITANIUM. BY H. SAEtfTE CLAIRE DEYILLE. 



Among the compounds of oxygen with simple bodies, there is a group of 

 substances whose analogies are incontestible, and which may be characterized 

 by a single feature in their history. These oxyds, which are not acted upon 

 by chlorine alone, become converted into chlorides when in contact with 

 charcoal, under the influence of a current of chlorine at a moderate tempera- 

 ture. Among them I shall mention those which will be referred to hi this 

 note, namely, silica, titanic acid and boracic acid. The radicals of these 

 generally-diffused substances have not yet been studied hi all their details, 

 and I now lay before the Academy the result of my researches upon this 

 subject. 



