OP ARTS AND SCIENCES. 35 



The reaction may, therefore, be written : — 



CH3 



/ 



NHjj N — CO 



/ / I 



C,H,(CH3)N,03 + H,0, = CO + CO CO 



\ \ I 



NH2 NH— CO 



Methyl paraban, C3lI(CIl3)N203. 



Although methylalloxan is so unstable in the presence of bases, in 

 acid solution it possesses remarkable stability. It may be boiled for 

 some time with strong nitric acid, or with hydrochloric acid aud 

 potassic clilurate before tbe red coloration with ammonia disappears. 

 On prolonged boiling (about an hour) with strong nitric acid, the 

 oxidation is complete, and the solution contains methylparaban. For 

 its preparation I have found it most advantageous to boil methyluric 

 acid with five or six parts of nitric acid of sp. gr, 1.3, until a drop 

 taken out fjives no coloration with ammonia. The excess of acid is 

 then driven off on the water bath, the syrupy residue diluted with a 

 little water, and well shaken out with ether. On distilling off the 

 ether, a syrup remains which soon crj'stallizes in shining radiated 

 prisms, which are recrystallized from hot water. Thej are somewhat 

 difficultly soluble in cold water, readily in hot ; soluble in alcohol and 

 ether. The substance melts at 149°. 5, sublimes very slowly at 100°, 

 and at higher temperature with great readiness. For analysis, the 

 air-dried substance was heated three hours at 100° ; duriug that time 

 0.2260 grm. lost 0.0030 grm. 



1. 0.1714 grm. gave 0.2333 grm. CO2. * 



2. 0.2160 grm. gave 0.0785 grm. H,0, and 0.2629 grm. COg. 



Found. 



1 2 



37.12 37.48 



4.04 



The substance gives no precipitate with calcic chloride, even after 

 the addition of ammonic hydrate. On warming the ammoniacal solu- 

 tion, a precipitate falls not wholly soluble in acetic acid. Argen- 

 tic nitrate precipitates it only in concentrated solution. The silver 

 salt prepared from concentrated solution, wnth the cautious addition of 



* The hydrogen in this analysis was lost. 



