272 VINEGAR, CIDER, AND FRUIT-WINES. 



oil) while barium carbonate remains behind. It is the best 

 material for the preparation of acetone. The decomposition is 

 best effected in a cast-iron vessel. With barium nitrate it gives a 

 well crystallizing double salt. 



Strontium acetate. This salt is prepared in a manner similar 

 to that of the preceding. The crystals obtained at 32 F. contain 

 5 equivalents of water and those at 59 F. 1 equivalent. 



With strontium nitrate it gives a double salt forming beautiful 

 crystals which contain 3 equivalents of water. On heating they 

 first yield their water of crystallization and then detonate, a 

 beautiful purple flame being formed. 



Magnesium acetate is prepared by dissolving magnesia alba or 

 usta in acetic acid. It crystallizes with difficulty and is readily 

 soluble in water and spirits of wine. Only a very small portion 

 of the solution is decomposed by ammonia. By dry distillation 

 it yields acetic acid, while magnesia remains behind. 



Aluminium acetate. The neutral salt A1 2 (C 2 H 3 O 2 ) 6 has never 

 been obtained in the dry state, it being only known in solution. 

 The pure combination can be prepared by introducing freshly 

 precipitated and thoroughly washed aluminium hydrate into 

 heated acetic acid. 



Aluminium acetate is of great importance in calico printing 

 and is used as a mordant under the name of red liquw. It is 

 manufactured for the use of the calico printer by adding to every 

 gallon of calcium acetate liquor 2{ Ibs. of alum, agitating the 

 mixture briskly and then leaving it to rest, in order that the 

 calcium sulphate may settle down. The decomposition of the 

 acetate is known by testing a small portion of the filtered liquid 

 in a tube with a concentrated solution of alum ; if a precipitate 

 of calcium sulphate falls, more alum must be added, till the acetate 

 of lime is completely decomposed. The liquor is next filtered 

 off, and the solution concentrated by evaporation till it acquires a 

 specific gravity of 1.087 to 1.1 ; it is then allowed to repose for 

 some time to deposit any sulphate of lime and finally drawn off 

 for use. The quality of this liquid as a mordant is inferior on 

 account of the imperfect decomposition of the lime-salt, and the 

 presence of a small portion of lime still retained in the red liquor 



