232 Ititelligence and Miscellaneous Articles. 



water, into anhydrous alloxan. If a hot saturated solution be al- 

 lowed to crystallize in a warm place, anhydrous alloxan is deposited 

 directly from the solution in oblique prisms, on the extremities 

 of which truncated rhomboidal octohedrons are seen. It is very 

 soluble in water, has a disagreeable odour, and a slightly saline 

 astringent taste, reddens vegetable colours, and causes a purple stain 

 on the skin. Treated with alkalies, alloxanic acid is formed ; but on 

 boilin"- it is decomposed into urea and, mesoxaUc acid. Heated 

 with peroxide of lead it is decomposed into urea and carbonate of 

 lead, with which a few traces of oxalate of lead are mixed. When 

 brought into contact with zinc and hydrochloric acid, with chloride 

 of zinc or sulphuretted hydrogen, alloxan tin is produced ; it is de- 

 composed by free ammonia into mykomelinic acid, by nitric acid 

 into parabanic acid, by sulphuric and hydrochloric acids into allox- 

 antin, by sulphurous acid and ammonia into thionurate of ammonia, 

 with alloxantin and ammonia into murexid. With a protosalt of iron 

 and an alkali, it forms an indigo-blue solution. Does not unite 

 without decomposition with the metallic oxides. 



The formation of alloxan and the other products which arise at 

 the same time, is dependent upon two perfectly independent decom- 

 positions ; namely, upon the conversion of cyanoxalic acid into 

 alloxan, and upon the mutual decomposition of urea and hyponitrous 

 acid. To 1 eq. of cyanoxalic acid are added the elements of 4 eq. 

 water, and 2 eq. oxygen from 1 eq. nitric acid, by which 1 eq. al- 

 loxan and 1 eq. hyponitrous acid are formed. The latter combines 

 with the ammonia of the urea, and liberates cyanic acid ; the hy- 

 ponitrite of ammonia is decomposed by heat into nitrogen and water, 

 and the cyanic acid with water is resolved into carbonic acid and 

 ammonia, which unites with the free nitric acid. 



Cyanoxalic acid =C8N2 O4 

 4 eq. water H4O4 



2 eq. o xygen O2 



1 eq. alloxan = C8N2H4O10 

 Urea =C3NoH40o 



Hyponi trous acid= N O3 



aN;H70s = CA+ Nj4- NHs-f- HO. 



Carbonic acid. Nitrogen. Ammonia. Water. 



It frequently happens that on dissolving the impure alloxan, for 

 the purpose of purifying by a second crystallization, a portion of 

 alloxantin is obtained ; it may be easily separated from the allox- 

 antin by cold water. 



ALLOXANIC ACID. 



Discovered by Wbhler and Liebig. Produced by the decomposi- 

 tion of alloxan by alkahes. It is prepared by decomposing alloxan- 

 ate of baryta by sulphuric acid. A strongly acid fluid is obtained, 

 which by gentle evaporation crystallizes in radiated groups of aci- 

 cular crystals ; it is a bibasic acid, dissolves zinc with the evolution 

 of hydrogen, is unchanged by sulphuretted hydrogen, and precipi- 

 tates the salts of silver, baryta, and lime. The anhydrous alloxanic 



