258 ALKALIES. 



4. PROPERTIES. 



(a.) Color white ; not deliquescent, but absorbs carbonic acid by 

 exposure to the air, and becomes a carbonate. 



(&.) Very soluble in water, but less so than potassa and soda, and 

 scarcely soluble at all in alcohol ; acrid, caustic, acts on colors as 

 the other alkalies do. 



(c.) Heated with platinum, it acts on the metal ; place on platinum 

 foil, with a small excess of soda, a piece of a lithia mineral as large 

 as a pin's head, and heat it with the blowpipe for two minutes ; a dark 

 color or dull yellow trace appears near the fused alkali, and the met- 

 al is oxidized by aid of the lithia and the air, while it is not affected 

 under the soda. The soda, by combining with the other principles 

 of the stone, liberates the lithia. 



(d.) Lithia has a higher neutralizing power than potassa and soda, 

 or even than magnesia ; its phosphate and carbonate are sparingly 

 soluble, its chloride is deliquescent and soluble in alcohol, and this 

 solution burns with a red flame ; all the salts of lithia give a red 

 color when heated on a platinum wire before the blowpipe. " Lithia 

 is distinguished from the alkaline earths by forming soluble salts with 

 sulphuric and oxalic acids," and the carbonate, * although difficultly 

 soluble in water, stains turmeric paper brown. The muriate and ni- 

 trate are deliquescent ; the concentrated lithia salts mixed with a 

 strong solution of carbonate of soda, deposit carbonate of lithia. 

 Bcrzelius. 



Some of these properties have been mentioned in anticipation, and 

 others are omitted or reserved for their more appropriate place. 



5. DECOMPOSITION. 



The metallic base was evolved by Sir H. Davy, by galvanism, but 

 it was too rapidly oxidized to be collected ; and the metal was, how- 

 ever seen to be white like sodium, and burned with bright scintilla- 

 tions. Composition supposed to be lithium, 56.50, oxygen, 43.50 

 = 100.00, or by Dr. Thomson, lithium 10, which he supposes to 

 be its equivalent number, and oxygen 1 proportion 8 = 18, for the 

 equivalent of the alkali. 



* Like the earthy carbonates, and it therefore forms an exception to the general 

 characters, stated p. 230, (d.) 



