EXAMINATION OF THE PANCREAS. 83 



also precipitate the filtrate or a part of it with phosphotungstic acid, 

 after first acidifying strongly with hydrochloric acid. Then warm 

 the tube, when the precipitate becomes more dense, packs together, 

 and usually sticks to the glass. Rinse it a few times with water, dis- 

 solve in dilute caustic soda solution, shake till the blue color, which 

 forms at first, disappears, then cautiously add the copper sulphate 

 solution. 



IV. NUCLEOPROTEID OF THE PANCREAS. 



The pancreas, according to Hammarsten, contains a nucleo- 

 proteid, which, according to Bang, may be split up into albu- 

 min and an acid, guanylic acid. The latter yields on cleavage 

 phosphoric acid, guanine, and a carbohydrate containing five 

 atoms of carbon, a pentose of the composition C 5 H 10 5 . The 

 nucleoproteid (nucleoalbumin) itself also yields the same 

 cleavage products, as Hammarsten had already found before 

 Bang. 



Detection: Heat 200 g. of finely chopped pancreas to 

 boiling with one liter of water, keep boiling for ten minutes, 

 filter, and add cautiously to the filtrate, while still warm, 

 about 10 to 15 cc. of 30 per cent, acetic acid, until a fine 

 flocculent precipitate begins to settle. If the precipitate does 

 not settle well it is advisable to heat again. Filter, wash 

 with water, remove the precipitate from the filter, grind it 

 with 50 cc. of absolute alcohol, filter, treat the precipitate 

 with about 50 cc. of ether, filter next day, wash once with 

 other, and grind. The presence of phosphorus and pentose 

 may be very easily shown in the somewhat impure nucleo- 

 proteid thus obtained. 



1. To detect the phosphorus fuse a small quantity with 

 the oxidizing mixture and then proceed as directed under 

 Casein, page 9. 



2. To detect the pentose the phloroglucin and the orcin 

 tests may be used. 



