2O 



Pp't. produced in Ppt. produced at the 



the cold. boiling temp. 



Solution in water (acid) No pp't. No pp't. 



" made neutral 

 made alkaline 

 " diluted 



The remainders of the solutions of these precipitates were 

 dialyzed free from sulphate and speedily evaporated to dryness 

 on a water bath at 40 C. The dialyzates contained little 

 or no protein, as shown by the practically negative results 

 with the biuret test. 



d. Osseoalbumoid was subjected to peptic digestion. It 

 was placed in an incubator at 9.15 A.M. and at 12.15, one-half 

 of the digestive solution was removed and precipitated by 

 saturation in the cold with (NH 4 ) 2 SO 4 , after careful neutraliza- 

 tion with NaOH. At the point of neutralization a voluminous 

 precipitate was obtained which was filtered off and, upon testing, 

 found to be easily soluble in dilute HNO 3 , to give a yellow 

 precipitate with ammonium molybdate and no protein reactions. 

 It was thought, therefore, that this precipitate consisted of 

 phosphates that had not been removed by the acid treatment 

 of the original ossein shavings. 



The (NH 4 ) 2 SO 4 precipitate produced by saturation at 

 room temperature was filtered off and the filtrate saturated 

 with (NH 4 ) 2 SO 4 at the boiling temperature. An aqueous 

 solution of these products did not yield a heat precipitation 

 test. 



The remaining half of the digestive mixture, after 8% hours' 

 digestion, was filtered, the filtrate neutralized, the phosphates 

 filtered off and (NH 4 ) 2 SO 4 added to saturation, as in the treat- 

 ment of the first half. 



A considerable amount of solid substance remained at the 

 end of the digestive treatment. This was subjected to peptic 

 digestion for 24 hours longer (a total of 32 hours) and then 

 filtered and treated by the (NH 4 ) 2 SO 4 process described above. 



Each of the precipitates was dissolved in water, dialyzed till 

 free from sulphate and speedily evaporated to dryness at 40 C. 



e. Fresh ox-femurs were used and osseoalbumoid was 



