On Chemical Tests. 



307 



b. A concentrated solution of lime is acted on as follows by the un- 

 dermentioned tests. 



Carbonate of potash ; or potash. Dense white fiocculent precipitate. 

 Sulphuric acid. Dense white powdery precipitate. 

 Oxalic acid. Dense white cloud which precipitates more slowly 

 than the others. 



c. Hydrochlorate of lime in crystals deliquesces, hydrochlorate of ba- 

 ryta does not. The crystals of the latter are four sided tables, the 

 crystals of hydrochlorate of strontian are delicate six sided prisms. 

 These characteristics may assist in distinguishing barytee, lime, and 

 strontia, from one another: see 72 e, and 79 d. 



45. CARBONATE of lime and some other carbonates, are useful in 

 analysis to separate different substances, see 65 c, d; 69 c. 



lUT. Carbonates are sometimes not acted on by acids when in com- 

 bination with alcohol and aether, see 73. 



46. CERIUM gives with the following tests the indications speci- 

 fied opposite to each. 



p j S A white voluminous precipitate; in- 



6 asi i soluble in excess of the precipitant. 



Ammonia 



Carbonate of potash K The same ; soluble in excess of preci- 



Carbonate of ammonia { pitant, but precipitated if boiled. 

 „, , . . j $ White precipitate in neutral solutions, 



Phosphate of soda } soluble in nitric and muriatic acid. 



Oxalic acid White curdy, do. do. do. 



« , , „ , , ( Crystalline precipitate, if the solution 



biuphate of potash . . . . -s , \ . ri \ r 



1 Jr ° **( be not too dilute. 



Prussiate of potash ... .White chalky precipitate. 



drosulphuret of ammonia Do. of protoxide of cerium. 



Sulphuretted hydrogen gas ) XT • ■, , 

 Gallic acid y J g \ No precipitate. 



Pure hydrate of cerium is white, becoming yellowish by exposure to 

 the air. The neutral salts redden litmus paper. 



a. The detection of protoxide of cerium in the compounds of protox- 

 ide of cerium which are insoluble in water is attended with some diffi- 

 culty, The best way is to dissolve such a compound in an acid and to 

 place a crust of crystals of sulphate of potash in the solution, which 

 will produce the double sulphate of protoxide of cerium and potash, 



The same; gelatinous. Insoluble in 

 an excess of ammonia. 



