VO Chittenden — Caseoses, Casein Dyspeptone, and Casein Peptone. 



It is to be seen from the table of aualytical results tliat the total 

 phosphorus is exactly equal to the phosphorus of the ash. The ash, 

 as examination showed, was composed almost entirely of calcium 

 phosphate with a trace of iron. There was no calcium sulphate. 

 Taking the percentage of phosphorus at the highest figure, viz: 2*67, 

 and calculating it to calcium phosphate Gdi^(Vo^„, it would be equal 

 to 13'3 per cent, of calcium phosphate, or within 0*3 per cent, of the 

 ash found. Hence, it would appear that the phosphorus present in 

 the substance probably existed there wholly as calcium phosphate. 



Digestion B. 



A quantity of pure casein, equal in amount to that used in digestion 

 A, was warmed at 40° C. with seven litres of 0*4 per cent. hydi'O- 

 chloric acid, to which a quantity of purified and vigorous pepsin solu- 

 tion was added. After being kept at 40° C. for fifty hours, two 

 litres more of 0*4 per cent, hydrochloric acid, together with some 

 pepsin solution, were added and the mixture warmed at 40° C. for 

 two days more, after which it was diluted with water and the undi- 

 gested residue allowed to settle out. The supernatant fluid was 

 syphoned off, the residue washed by decantation and then again 

 treated at 40° C. with five litres of an active pepsin-hydrochloric acid 

 solution for four days. The residue still undigested was filtered ofl', 

 washed with water, dissolved in one per cent, sodium carbonate solu- 

 tion and the alkaline fluid filtered from the small amount of undis- 

 solved matter. From this fluid, the dyspeptone was precipitated by 

 hydrochloric acid, the acid compound washed thoroughly with water, 

 after which it was warmed at 40° C. for forty-eight hours with 1200 

 c. c. of 0*2 per cent, hydrochloric acid, and 50 c. c. of a strong pepsin 

 solution. The undigested residue, after being thoroughly washed, 

 was dissolved in 800 c. c. of one per cent, sodium carbonate, the solu- 

 tion exactly neutralized with hydrochloric a-cid and dialyzed until 

 chlorides were entirely removed. The clear aqueous solution was 

 evaporated to a syrup and the dyspeptone j^recipitated with alcohol, 

 after which it was treated exactly as preparation A. 9*5 grams 

 of pure, dried substance were obtained. 



For analysis, the dyspeptone was dried at 110° C. until of constant 

 weight. The analytical results are shown in the accompanying 

 table. 



The ash which was larger than in the first preparation, contained 

 no sulphate whatever, but was composed in great part of calcium 

 phosphate. 



