ANIMAL OXIDES WITH AZOTE NOT OILY. 



acid solution of uric acid. Wohler and Liebig have ascertain- 

 ed that both these substances are present, and the former in 

 greater proportion, and that the decompositions which take place 

 are very complicated. 



If we boil a solution of alloxantin in ammonia till the colour 

 at first induced disappears, allow the liquid to cool down to 158, 

 and then add a solution of alloxane, every drop we add the pur- 

 ple colour of the liquid increases in intensity, till at last it be- 

 comes quite opaque. Soon after we see formed on the sides of 

 the vessel and the surface of the liquid brilliant green crystals 

 of murexide. But the quantity of them is never proportional to 

 that of the substances employed. Sometimes these crystals are 

 mixed with red flocks of uramile, easily separated by washing 

 them cold in caustic ammonia. 



The principal result of the action of ammonia on alloxantin 

 being the production of uramile, it was natural to think that the 

 formation of murexide depended on the action of alloxane on 

 uramile while ammonia was present. They found that when a 

 solution of alloxantin with sal-ammoniac or oxalate of ammonia 

 is heated till the decomposition was effected and the uramile 

 formed, if enough of ammonia be added to redissolve the preci- 

 pitate at first formed, and after that a solution of alloxane be 

 poured in, the colour becomes very intense, and murexide sepa- 

 rates in considerable quantity. 



We obtain murexide in great beauty, though in no great quan- 

 tity, when, after having decomposed alloxantin by sal-ammoniac, 

 we filter oft 7 the uramile formed and saturate the residual liquid 

 with carbonate of ammonia. Uramile dissolved in ammonia and 

 treated with alloxane always gives murexide. 



The co-operation of alloxantin in the production of murexide 

 seems merely to consist in the formation of uramile ; but in 

 what way alloxane acts seems still an enigma. 



Wohler and Liebig observed that a simple solution of uramile 

 in ammonia, evaporated by the assistance of heat, and boiled for 

 some time, assumes a deep purple colour, and gives, on cooling, 

 a great quantity of murexide. This would seem to prove that 

 alloxane does not contribute to the formation of this product, but 

 by abandoning a portion of its oxygen. This led them to try 

 whether other substances easily parting with oxygen might not 

 be substituted for alloxane. 



