1839.] 



On Chemical Tests. 



321 



g. Lime and magnesia are frequently found together in magnesian 

 lime stone • they may be separated as shewn under the article magnesia, 

 79 e. 



73. LIME, carbonate of. Anhydrous alcohol; sulphuric aether; 

 and acetic aether disguise more or less the properties of the strongest 

 acids, Their solution in these etherial spirits does not redden litmus 

 paper nor decompose a great number of the carbonates. But artificial 

 carbonate of lime, and even marble itself is attacked with extreme vio- 

 lence by a solution of muriatic-acid-gas in alcohol, although diluted 

 with many times its volume of water. This gas in alcohol attacks, 

 also, but less strongly the carbonates of barytes, strontia, magnesia and 

 soda, even when they have been previously calcined ; but it does not 

 decompose carbonate of potash. Concentrated nitric acid mixed with 

 alcohol does not decompose carbonate of potash, but it acts energeti- 

 cally upon the carbonates of lime and strontia; it acts less powerfully 

 on the carbonates of barytes, magnesia, and soda. 



a. Oxalic acid which disengages carbonic acid from the carbonates 

 of strontia, magnesia, and barytes does not act at all on the carbonate 

 of lime, or of potash in alcoholic solutions. These facts shew that on 

 some occasions in which alcohol is employed in chemical investiga- 

 tions, it will prevent the operator from discovering the presence of an 

 acid by litmus paper. 



b. A mixture of about six parts of absolute alcohol and one part of 

 concentrated sulphuric acid does not act upon any neutral carbonate; 

 but it decomposes acetate of potash. 



e. Carbonate of lime, and some other carbonates are useful in analy- 

 sis to separate different substances, see 65 c. d. and 69 c. 

 d. To distinguish carbonate of lime from lime, see 67 b. 



74. lime, muriate of, may be used as an auxiliary to discover alka- 

 line carbonates. The carbonates of potash, soda, or ammonia separates 

 from this test the lime, and the muriatic acid in the test combines with 

 the alkali producing muriate of potash, soda, or ammonia, as the case 

 maybe. The alkaline base must be discovered by appropriate tests, 

 see 28, 98, 110. 



75. lime WATER, detects carbonic acid producing a white preci- 

 pitate of carbonate of lime. With salts having a base of magnesia or 

 alumina, and with sulphates it gives a cloudiness or a precipitate. It also 

 detects corrosive sublimate producing a precipitate of a yellow, or brick 

 dust colour, which becomes transparent on the addition of an acid. 



