1903.] 



On the Nucleoprotcids of the Pancreas, etc. 



393 



tion, we have to remark that we noticed several times that very 

 slight lrevorotatory filtrates were obtained when hydrochloric acid was 

 used for precipitating the proteid, and especially when the acid fluid 

 was allowed to remain in contact with the precipitate. Presumably, 

 the negative rotation is due to an optically negative acid albumin 

 being formed, which is soluble in the dilute hydrochloric acid. 



As in the case of the nucleoproteid, a solution of the nuclein yields 

 a coagulum on heating, and the rotation of the solution is not appre- 

 ciably changed. This would lead one to assume the existence of a 

 nuclein of which the specific rotation is greater than + 64 0, 4. It can 

 -easily be proved that such a substance exists in the preparation which 

 we have designated " residual material.' 5 



A weighed amount of this substance was dissolved in a measured 

 volume of water. The solution was examined with the polarimeter, 

 treated with hydrochloric acid, and the amount of matter determined 

 in the filtrate, which was found to be optically inactive. The follow- 

 ing data were obtained : — 



Weight of substance taken 0-520 gramme. 



Weight of optically inactive matter ... 0*269 „ 



Weight of optically active matter 0*251 



Volume of solution 25 c.c. 



Observed angle +1° 38' 



Length of tube 200 mm. 



[o] D = +81°-1. 



C. Hammarsten's Preparation. 



As we have already explained, Hammarsten's so-called nucleopro- 

 teid-/^, which is obtained from an extract of pancreas made by boiling 

 the finely comminuted gland in water must, ipso facto, be a nuclein. 

 The results which we had obtained and which have been described, 

 made it highly desirable that we should make an optical examina- 

 tion of this substance also. By slight departures* from the method 

 described by Hammarsten, which were absolutely necessary to remove 

 the colouring matter, but which cannot possibly have exercised any 

 influence on the chemical nature of the product, we were able to pre- 

 pare a nuclein which must have been identical with Hammarsten's 

 preparation (nucleoproteid-/?), The substance which we obtained is 

 soluble in water, and gives a violet biuret reaction. Its solution was 

 comparatively highly coloured, but possessed so great a rotatory 



* We used ammonia for redissolving the nuclein, instead of a fixed alkali 

 employed by Hammarsten. We also finally poured an aqueous solution of the 

 nuclein into 95 per cent, alcohol, and washed by decantation with absolute alcohol 

 and ether. 



