Am.  Jour.  Pharm. 
Nov.,  1886. 
Peptones. 
569 
remainder  of  the  salt  was  removed  by  aqueous  baryta,  and  the  last 
traces  by  barium  carbonate;  dilute  sulphuric  acid  was  added  to 
remove  the  baryta,  and  the  barium  sulphate  filtered  off.  From  the 
filtrate  the  peptones  were  precipitated  by  alcohol,  redissolved,  and 
again  precipitated  by  phosphotungstic  acid,  and  dried.  In  the  case 
of  amphopeptone,  the  first  analyses  were  invalidated  by  adherent 
pepsin,  and  a  substance  designated  mucin-peptone,  apparently 
derived  from  the  mucous  membrane  of  the  stomach  ;  it  forms  a 
sticky,  elastic  precipitate  with  alcohol,  but  was  not  further  investi- 
gated. The  error  due  to  these  admixtures  was  obviated  by  saturating 
concentrated  artificial  gastric  juice  with  ammonium  sulphate  ;  this 
precipitates  the  mucin  and  pepsin  ;  pepsin  alone  redissolves  in  dilute 
hydrochloric  acid ;  this  solution  was  used  as  a  digestive  fluid ;  from 
it  no  mucin-peptone  was  obtained.  The  remains  of  the  pepsin  were 
subsequently  removed  by  the  ammonium  sulphate  with  the  albumoses. 
Antipeptone  was  prepared  both  from  fibrin  and  by  the  pancreas 
being  allowed  to  digest  itself. 
The  following  table  gives  some  of  the  results  obtained  in  the 
analyses  of  these  substances..  In  each  case  the  samples  had  been 
purified  by  means  of  phosphotungstic  acid.  I.  Amphopeptone  from 
fibrin ;  II.  Antipeptone  from  fibrin ;  III.  Antipeptone  from  the 
pancreas : — 
C.         H.          N.         S.  O.  Ash. 
1   48-75     7-21     16-26     0-77     27-01  3-22 
II   46-59     6  69     18-28     0.67     27-77  3-67 
III   44-47     7-15     17-94     0-57     29-87  2-07 
Contrasted  with  previous  analyses,  the  numbers  obtained  show 
about  1  per  cent,  less  carbon,  1  per  cent,  more  nitrogen,  and  0'3  to 
0*4  per  cent,  less  sulphur.  The  percentage  of  nitrogen  is  greater  in 
antipeptone,  especially  in  that  obtained  from  the  gland,  than  in 
amphopeptone. 
The  following  are  the  chief  properties  of  pure  peptone :  When 
dissolved  in  water,  it  hisses  and  froths  in  the  same  way  that  phos- 
phoric anhydride  does;  heat  is  at  the  same  time  evolved.  Its  solution 
in  water  is  brown,  which  prevents  its  Isevorotary  power  from  being 
estimated.  Its  taste  is  somewhat  cheesy,  but  not  unpleasant.  The 
bitter  taste  of  artificially  digested  food  must  therefore  be  due  to  some 
product  not  yet  separated,  native  proteidsand  albumoses  being  almost 
tastekss.    Peptones  are  not  precipitated  by  sodium  chloride  in  acid 
