158 MALONIC ACID. 



84) with alkalies ; by decomposing barbituric acid (see 

 Uric Acid) with caustic potassa; and by oxidation of 

 sarcolactic acid, of propylene and allylene. 



Properties. Large, lamellar crystals, easily soluble 

 in water and alcohol ; fuses at 132 and breaks up at a 

 higher temperature into carbonic anhydride and acetic 

 acid. The barium salt C 3 H 2 O 4 Ba+H 2 forms silky 

 tufts; the calcium salt (C 3 H 2 4 Ca) 2 +3JH 2 0, small trans- 

 parent needles. Both salts are difficultly soluble in 

 cold water. 



Nitroso-malonic acid, C 3 H 3 (M))0 4 , is formed by 

 heating potassium violurate (see Uric Acid) with caustic 

 potassa. Shining, prismatic needles, very easily soluble 

 in water. Fuses, when heated, and then decomposes with 

 a sharp report. 



Amido-malonie acid, C 3 H 3 (TH 2 )0 4 , is formed by 

 the action of nascent hydrogen (sodium-amalgam and 

 water) on nitroso-malonic acid. Large, shining prisms, 

 easily soluble in water. Is decomposed , by heati ng alone 

 or by warming its aqueous solution, into glycocine and 

 carbonic anhydride. 



Mesoxalic acid, C 3 H 2 5 =COJ QOOH The ba ~ 



rium salt is produced by boiling barium alloxanate (see 

 Uric Acid) for five or ten minutes with a great deal of 

 water (to 15 grms. of the salt 1 litre water). From this 

 is obtained the free acid by heating with the required 

 amount of sulphuric acid, at 40-50, and evaporating 

 the filtrate. It is further formed by adding iodine to 

 a solution of amido-malonic acid, which contains potas- 

 sium iodide. Prismatic crystals, very deliquescent, also 

 easily soluble in alcohol. The acid dried at 100 still 

 contains a molecule of water of crystallization. It 

 fuses at 150 without giving off this water, and decom- 

 poses at a somewhat higher temperature. 



Barium mesoxalate, C 3 5 Ba -f lpI 2 0. Colorless, 

 microscopic crystals, almost insoluble in water, soluble 

 with difficulty in hot water. Lead mesoxalate CWPb -f 



