Intelligence and Miscellaneous Articles. 233 



acid contains the constituents of half un equivalent of alloxan minus 

 1 eq. water. 



Its formula is C^NHjOs + 2 eq. 



ALLOXANIC ACID AND METALLIC OXIDES. 



Alloxanic acid neutralizes the alkalies perfectly, decomposes the 

 carbonates, and forms, when neutralized by ammonia, with the salts 

 of silver a white precipitate, which by boiling becomes first yellow 

 and then black, the change being accompanied by a rapid efferves- 

 cence ; treated with ammonia in excess, it produces white gelatinous 

 precipitates with the salts of lime, strontia, and baryta; but the 

 precipitate is redissolved by a large excess of water, and readily by 

 an acid. The solutions of the neutral alloxanate of lime, strontia, 

 and baryta, become turbid when boiled, the bases are precipitated, 

 and urea and raesoxahc acid are formed. 



Alloxanate of Baryta —Prepared by adding barj'tic water to an 

 aqueous solution of alloxan at the temperature of 140° ; on each 

 addition a white precipitate is formed, but it is redissolved by stir- 

 ring ; the barytic water is added in successive portions till the pre- 

 cipitate is permanent, when the solution is allowed to cool. The 

 mother-liquor separated from the crystals is again to be heated and 

 treated with barytic water as before, and this should be repeated as 

 long as crj'stals are obtained. 



Short .transparent needles, or mother-of-pearl scales, which at 

 212° become milk-white and lose 3 eq. water; at 300° they are an- 

 hydrous ; they are sparingly soluble in cold, but more freely in hot 

 water ; exposed to a red heat they leave a mixture of carbonate of 

 baryta and cyanuret of barium. 



Its formula is CRN2H208,2BaO + 8 aq. 



Alloxanate of Silver.— \ white insoluble powder, which produces 

 a slight explosion when heated ; the residue after being heated to 

 redness yields cyanic acid and metallic silver. 



Its formula is CcNoH.Os + 2AgO. 



MESOXALIC ACID. 

 When a saturated solution of alloxanate of baryta or strontia is 

 heated to the boiling point, a precipitate falls consisting of the car- 

 bonate, mesoxalate, and alloxanate of baryta or strontia. The so- 

 lution, on evaporation, yields a crystalline crust, from which urea is 

 separated by treating it with alcohol, and mesoxalate of baryta re- 

 mains. If a solution of alloxan be added, drop by drop, to a boiling 

 solution of acetate of lead, a very heavy granular precipitate of mes- 

 oxalate of lead is formed, and urea remains as the only other product 

 in the solution. The mesoxalic acid may be obtained by decom- 

 posing this lead salt by sulphuric acid ; it is a strongly acid solution, 

 reddens vegetable colours, and forms, like the alloxanic acid, on the 

 addition of ammonia, jjrecipitates with the salts of baryta and lime, 

 which are soluble in acids and a large excess of water ; it may be 

 boiled and evaporated without change. Its action on the salts of 



