246 XANTHINE SARCINE. 



bonic anhydride, and ammonia are the final products 

 of the action of barium hydroxide on allantoine. 



Xanthine (Xanthic oxide), C 5 H 4 K 4 2 . Is formed 

 by the reduction of uric acid by means of sodium- 

 amalgam. Occurs in urine, in muscular flesh, and in a 

 number of glandular organs. In large quantity in 

 certain rare urinary calculi which are found in human 

 bladders and often consist entirely of it. Further, it 

 occurs in some varieties of guano from which it can be 

 extracted by caustic soda and afterward precipitated by 

 carbonic anhydride. After the use of sulphur baths, it 

 appears in larger quantity in the urine. In the form of 

 calculi, it has a brownish flesh-color. In a purified 

 state it forms a white, amorphous mass, or small scales. 

 Insoluble in cold water, very difficultly soluble in hot ; 

 sublimable, but only with partial decomposition. Com- 

 bines with acids and bases. It dissolves in ammonia 

 and the boiling saturated solution deposits crystals of 

 xanthine-ammonia on cooling. Silver nitrate gives a 

 precipitate, C 5 H 4 ]!^ 4 2 + Ag 2 0, in an ammoniacal solu- 

 tion, which is insoluble in ammonia, soluble in hot 

 nitric acid. 



A compound isomeric with xsniihine^pseudoxanthine^ 

 is produced together with hydurilic acid and glycocol 

 by heating uric acid with concentrated sulphuric acid. 



Sarcine (Hypoxanthine), C 5 H 4 N 4 0, is formed by long- 

 continued action of sodium-amalgam on uric acid or 

 xanthine. Occurs in a great many of the animal 

 organs and fluids ; in muscular flesh, particularly in the 

 cardiac muscles of the horse ; in the liver and the spleen 

 of the ox ; in the human liver in certain diseases of this 

 organ; in urine; in blood, etc. It is always accom- 

 panied by xanthine. Microscopic, needly crystals, dif- 

 ficultly soluble in cold water, more easily in hot, but 

 sparingly in alcohol. It is readily dissolved by alkalies, 

 as well as by diluted acids, crystalline compounds being 

 formed. It combines also with salts. On the addition 



