96 J. ^Y. MaJht—ConsiituHonalformuloe of Urea, 

 Alloxantine, CgH.N.O^, may be represented as 



clearly exhibiting the analogy of this body to oxalantine, and 

 its production in a similar way by the coalescence of two 

 molecules of alloxan with separation of oxygen (or a molecule 

 of alloxan and one of dialuric acid with the additional separa- 

 tion of water). The formula of Gibbs for alloxantine would 

 seem to imply that it is a monobasic acid (or, according to the 

 exact terms of his own definition,* tribasic). 



Finally, it is difficult to suggest with confidence a formula 

 for the problematical substance 'murexide, CeHgNgOe. If an 

 amide character be admitted for it ; and it does seem that evi- 

 dence is still wanting to conclusively prove that it is an ammo- 

 nium salt, especially in view of non-production of purpuric 

 acid and the undoubted existence of isomeric iso-purpurates 

 (and possibly other salts) which may have led to an undue 

 assumption of identity of type between murexide and its metal- 

 lic derivatives ; we may perhaps assume this substance to have 

 the formula No. 1, 



dde (neutral). 



Murexide (neutral). 



H-N- 



A i h 



i i i i i A 



in which the union of two molecules of dialuramide is effected, 

 with elimination of hydrogen, by the linking together of the 

 ureic carbon atoms. This view of the constitution of murexide 

 (making it alloxantine-amide) obviously affords a simple explan- 

 ation of its production from dialuramide by oxidation, from 

 ammonium dialurate by heating, from alloxantine and alloxan 

 by the action of ammonia, «&c., and also suggests the probable 

 * Loc. cit.,— "cyanylmaybe regarded as the acidifying term. It8 quantity, 



