TAETARIC ACID. 183 



and ammonium chloride. Is deposited from a mixture 

 of lime-water, with an excess of tartaric acid, in the 

 form of large shining crystals. 



Lead tartrate, C 4 H 4 6 Pb, white voluminous pre 

 cipitate, insoluble in water. Soluble in ammonia. 

 When this solution is boiled, there is thrown down a 



salt C 4 H 2 6 Pb 2 = C 2 H 2 (Pb) j QQ Pb * 



Antimonyl-potassium tartrate (Tartar emetic), 

 C 4 lI 4 6 (SbO)k + JH 2 0, is prepared by digesting anti 

 mony oxide with cream of tartar and water. Crys 

 tallizes in shining octahedral or tetrahedral crystals, 

 which lose their water of crystallization at 108, and 

 become white and opaque. Soluble in 14 parts of 

 water of the ordinary temperature. Acids precipitate 

 from its solution insoluble antimony compounds. 

 Barium, lead, and silver salts precipitate salts which 

 are analogous in composition to tartar emetic. At 

 200 the anhydrous salt loses another molecule of 

 water, and is converted into a salt C 4 II 2 6 SbK (analo 

 gous to the lead salt C 4 H 2 6 Pb 2 ), from which with the 

 aid of water tartar emetic is regenerated. 



Ethyl tartrate, COT isformed 



when hydrochloric acid gas is conducted into an alco 

 holic solution of tartaric acid. Liquid ; mixes with 

 water ; not volatile without decomposition. Ethyl- 



tartaric add CWB?^^ j QQ QH^&quot; When a solution of 

 tartaric acid in absolute alcohol is evaporated, this com 

 pound is left behind. Crystalline, very deliquescent, 

 easily decomposable acid. 



Ethyl acetyltartrate,C 2 H 2 (gg 2H3 ) j ^a 



and ethyl diacetyltartrate 



( CO.O.C 2 !! 5 



1 CO C 2 IP resu &quot; ; f rom the action of acetyl chloride 



