OF ARTS AND SCIENCES. 31 



It will be seen that this reaction proves the commonly accepted view 

 that uric acid is not an hydroxyl but an iniid acid. 



In order further to establish tlie relative position of the methyl 

 radical, it seemed to me of chief importance to follow it through oxida- 

 tion in alkaline and acid solution, and thus determine its relation to 

 allantoin and alloxan or paraban. 



Methylallantoin. C^H. (CHg) N^^. 



Methyluric acid is readily oxidized in alkaline solution, according to 

 the metliod of Claus and Emde.* The .solution must be dilute with 

 but a small excess of alkali, the potassic permanganate added slowly 

 in exact molecular proportion. As soon as the manganese dioxide has 

 separated, it must be filtered rapidly with the aid of the pump, and the 

 filtrate slightly acidified with acetic acid. I then found it most ad- 

 vantageous to evaporate as quickly as possible on the water bath to 

 small volume. After standing twenty-four hours, the methylallantoin 

 crystallizes out in clusters of radiated prisms. These separated from 

 the mother liquor by pressure, and recrystallized several times from 

 hot water, form clear distinct monoclinic prisms, closely resembling 

 ordinary allantoin. They are readily soluble in hot water, sparingly 

 in cold ; almost insoluble in alcohol, hot or cold, and insoluble in 

 ether. These crystals melt with decomposition at 225°. 



In spite of many variations of the method, I could obtain in this way 

 but fifteen per cent of the theoretical yield. From the mother liquors 

 evaporated to a syrup, alcohol separates a potash salt, probably of 

 methylallantoic acid. On account of its uninviting character it was 

 not further examined. 



Methylallantoin dried at 100° gave, on analysis, — 



0.23G2 grm. gave 0.1092 grm. 11,0, and 0.2978 grra. COg. 



Calculated for Found. 



C,H,(CIl3)NA. 

 C 34.89 34.39 



H 4.65 5.13 



Silver nitrate gives in a hot saturated solution on the cautious addi- 

 tion of ammonic hydrate, a crystalline precipitate consisting of needles 

 or short prisms. This salt is readily soluble in hot water, more 

 sparing'y in cold. By spontaneous evaporation of the cold solution, 



* Bericlite Deutsch. Chera. Gesellsch. VII. 226. 



