62 ACETIC ACID. 



oxyde and carbonic anhydride, while the acetic acid will 

 distil over unchanged and highly concentrated, at a 

 temperature not exceeding 120 C. 



3. Place this concentrated distillate in a tube in a 

 mixture of ice and water. It will begin to form white 

 crystals below 16 C., and ultimately solidify in a white 

 crystalline mass. 



4. Allow to thaw, and pour off the portion first 

 liquefied, which is somewhat watery. 



5. Place the crystals in a very small retort, provided 

 with a thermometer in its tubule, and with a condenser 

 attached to its neck, and heat. The acetic acid will 

 distil over completely at 120 C., giving an inflammable 

 vapour. 



6. Unite the decanted and distilled acid, and dilute 

 with water. Boil with excess of pure baryum carbonate, 

 filter, and evaporate to crystallisation. The crystals, 

 monohydrate of baryum acetate, C 4 H 6 Ba0 4 + H 2 0, 

 contain 6*59 per cent, of water of crystallisation, to be 

 expelled at 100 C., and 50*18 per. cent, of Ba, to be 

 determined as sulphate, by heating in platinum crucible 

 with sulphuric acid. 



7. Heat some dry baryum acetate ; it will fuse, and 

 give off vapours of acetone. 



8. Dissolve the baryum acetate in water, heat, and 

 decompose exactly with sodium carbonate. Filter from 

 baryum carbonate, and examine the solution of sodium 

 acetate as follows. 



9. Add a few drops of ferric chloride : a dark red 

 colour will be produced. Boil ; a brown-red precipitate 

 will fall, leaving the liquid colourless. To another 



