J. W. Mallet — Constitutional formulce of Urea, 

 2. Glycolurile(] 



By reference to the formula proposed further on for allantoine 

 it will be seen how simply the production from it of hjdantoine 

 occurs with separation of urea. Glycolurile, C^HgN^Og, ap- 

 pears (2) as the corresponding di-ureide of glycollic acid, and 

 its relation to allantoine (from which it is producible by the 

 action of sodium amalgam) will be easily seen by reference to 

 the formula for the latter, although I prefer to view these 

 bodies as derivatives of two different acid nuclei. The break- 

 ing up of glycolurile by an acid in the presence of water into 

 hydantoiiie and urea is easily traced. From oxalic acid, 

 C.H^O,, we get oxaluric acid,* C3H,N,0„ 



1. Oxalic acid (dibasic). 2. Oxaluric acid (monobasic). 3. Paraban. 



u 



Lo-H 



easily breaking up in presence of wa 



..i 



6 : 



The absence of well determined acid character in paraban 

 (parabanic acid), C3H3N3O3, justifies the above formula, No. 

 3, which well explains Ponomareif sf synthesis of this body by 

 the action of phosphorus tri-chloride on a mixture of oxalic 

 acid and urea, as well as the ready conversion into oxaluric 

 acid by assumption of water ; while the so-called metallic salts 

 formed by this body (including those described by Menschut- 

 kin),:|: remarkable for their instability, may probably represent 

 merely the substitution of amidic hydrogen in the urea residue, 

 as cholestrophane results from the substitution of both these 

 hydrogen atoms by methyl. It will be seen presently that 

 this formula makes paraban bear exactly the same relation to 

 oxalic acid that alloxan does to mesoxalic acid. 



