M. Strecker on the Artifcial Formation of Xanthine. 135 



Xanthine or xanthic oxide, a nitrogenous basic substance which 

 was discovered by Marcet as a rare constituent in urinary calculi, 

 has considerable similarity with sarcine and with guanine. It 

 contains the elements of uric acid and of sarcine, 



2CioH4N'i04=CioH4N4 06 + CioH4N4 02. 



Xanthine. Uric acid. Sarcine. 



But it was impossible to effect its formation by acting on urate 

 of potash with hydrochlorate of sarcine. 



Sarcine has been declared by Scherer* to be identical with 

 hypoxanthine, a substance which he discovered some time ago 

 in the animal organism. The same chemist has found that xan- 

 thine is a normal constituent of the human and animal organism. 

 Between guanine and sarcine there exist similar relations to 

 those which exist between glycocol and acetic acid, as is seen by 

 the equations, 



CJ0H5N5O2=C'0H''N4O2 + NH. 

 Guanine. Sarcine. 



Glycocol. Acetic acid. 



Streckerf, in the expectation of being able to transform gua- 

 nine into sarcine, tried some experiments on a nitrogenous deri- 

 vative of guanine. This substance was first obtained by Neu- 

 bauer and Kerner J, by dissolving guanine in nitric acid and 

 adding small fragments of nitrite of potash, which dissolves with 

 a lively disengagement of gas, but without formation of binoxide 

 of nitrogen. When red vapours appear, the liquor is added to a 

 large quantity of water, by which orange-yellow flakes are pre- 

 cipitated. These are washed, and then crystallized from boiling 

 water. The substance did not give very accordant results to 

 analysis ; and it was impossible to decide whether its formula was 



Strecker dissolved this nitro-compound in potash, and then 

 added ferrous sulphate and boiled the liquor. A black precipi- 

 tate of ferroso-ferric oxide was formed, which was filtered off"; 

 and the colourless filtrate, treated with acetic acid, gave a floc- 

 culent precipitate, which was collected and washed with cold 

 water. It was neither guanine nor sarcine, but was found to be 

 identical in its properties and composition with Marcet^s xanthic 

 oxide. It is a white or yellowish powder, soluble in 723 pai'ts 

 of boiling, and in 1950 of cold water. Its jjotash solution, ex- 

 posed for some time to the air, deposited crystalline plates, which 



* Liebig's Annalen, March 1858. t Ibid. November 1858. 



X Ibid. vol. ci. p. 318. 



