392 



Profs. A. Ganigee and W. Jones. 



[Feb. 9, 



the pancreas, prepared in substantially the same manner as the pre- 

 parations employed in the present research, yields, when subjected to 

 hydrolytic treatment, two of the xanthine bases, viz., guanine and 

 adenine, and in a ratio which closely approximates four equivalents 

 of the former to one of the latter. The " nuclein " and " residual 

 material " of the present research were also found to yield xanthine 

 bases on hydrolysis with sulphuric acid. All the three preparations 

 under discussion contain phosphorus, all are completely precipitated 

 from aqueous or faintly alkaline solutions by the addition of a trace 

 of hydrochloric c>cid, and all yield precipitates when their neutral 

 solutions are boiled. 



Optical Properties of the Nuclein. 



We had convinced ourselves by the following experiment that the 

 specific rotation of the substance which we have denominated 

 " nuclein " would be found to be greater than that of the nucleo- 

 proteid, before we had the opportunity of making a careful optical 

 examination of the former substance. 



A perfectly neutral solution of the neucleoproteid was prepared by 

 treating some of the substance with water and an insufficient amount 

 of ammonia to effect complete solution. The filtered fluid, examined 

 with the polarimeter in a 200 mm. tube, gave a rotation of 1° -16'. 

 The solution was heated to boiling, and the coagulated albumin 

 filtered off. The nitrate polarised in a 200 mm. tube gave a rotation 

 of 1° 49'. Now, as is well known, the process of boiling, removing a 

 portion of the albuminous matter previously forming part of the com- 

 plex nucleoproteid molecule, converts the latter into a nuclein. As 

 the length of the tube was the same, and the angle of rotation re- 

 mained sensibly constant in our experiment, a decrease in the amount 

 of matter in solution (equal to the coagulated albumin removed from 

 it) must mean an increase in the specific rotation. 



The following direct determination of the specific rotation of the 

 nuclein was made. The body was dissolved in water, and as the fluid 

 was somewhat coloured, it was examined in a shorter tube than those 

 which we have usually employed : — • 



Weight of substance 1 *009 gramme. 



Volume of solution 50 c.c. 



Observed angle +1° 18' 



Length of tube 100 mm. 



[a] D = +64°-4. 



The solution was treated with hydrochloric acid to precipitate the 

 nuclein, and the filtered fluid examined in a tube 200 mm. long. The 

 rotation was slightly negative (0°9'). In reference to this observa- 



