^°^'sept'"i885*'^°^'}     Nitrogenous  Substances  in  the  Gastric  Juice.  455 
after  that  there  are  ferments  in  the  organism  which  have  the  power  of 
digesting  albumin,  it  must  be  remembered  that  such  ferments  have  a 
less  powerful  action  than  either  the  gastric  or  pancreatic  juices,  and  that 
food  materials  which  are  unaffected  by  these  two  secretions  are  prob- 
ably valueless  as  nourishment. 
To  prepare  the  extract  of  pancreas,  the  author  took  the  pancreas  of 
an  ox  (400  grams),  freed  as  much  as  possible  from  fat,  exposed  it  freely 
to  the  air  for  24  hours,  rubbed  it  down  finely  with  sand,  covered  it 
Avith  dilute  glycerol  (1  litre  glycerol  and  1  litre  water),  and  after  4 — 6 
days  pressed  and  filtered.  When  used,  this  extract  must  always  be 
made  alkaline  by  the  addition  of  soda. 
Some  of  the  experiments  were  made  to  determine  if  soda  alone  was 
able  to  dissolve  nitrogenous  compounds.  Two  samples  of  finely  ground 
barley  straw  were  digested  with  artificial  gastric  juice,  after  which  there 
remained  in  the  undissolved  portion  a  mean  of  0*206  per  cent,  nitrogen. 
After  further  digestion  with  J  per  cent,  soda  solution  at  40°  for  several 
hours  there  remained  nitrogen  undissolved  0'105  per  cent.  Experi- 
ments with  leaves  of  grass  and  palm-nut  kernels  yielded  similar  re- 
results.  Whether  the  soda  acts  simply  as  a  solvent  or  causes  a  true 
decomposition  of  the  substances  acted  on,  is  a  question  the  author  cannot 
answer. 
A  quantity  of  palm-nut  cake  was  first  treated  with  freshly  prepared 
acid  pepsin  solution,  after  which  it  contained  an  average  of  0*461  per 
-cent,  nitrogen.  Portions  were  then  treated  with  100  cc.  of  pancreas 
extract  to  2  grams  of  residue  (a  proportion  preserved  in  all  the  experi- 
ments), J  and  1  per  cent,  soda  solutions  being  used  to  give  an  alkaline 
reaction.  The  results  were  negative,  the  differences  being  within  the 
limits  of  experimental  error.  Other  observations  convince  the  author 
that  J  to  1  per  cent,  soda  solution  without  any  ferment  act  as  solvents 
equally  well  as  when  pancreas  ferment  is  present;  this  he  explains  by 
the  organic  matter  from  the  pancreatic  glands  dikiting  the  soda  and 
gradually  diminishing  its  solvent  powers. 
A  mixture  of  lucerne  and  grass  hay  which  left  a  residue  after  diges- 
tion of  0*293  per  cent,  nitrogen,  after  treatment  with  pancreas  solution 
containing  1  per  cent,  soda,  left  0*213  per  cent.;  with  |-  per  cent,  soda, 
0*271  per  cent.  In  the  former  case  27  per  cent.,  in  the  latter  but  7 
per  cent,  of  the  difficultly  soluble  nitrogen  was  dissolved.  Similar 
experiments  with  the  following  substances  show  the  percentages  dis- 
solved by  the  pancreas  solutions  : 
Cocoa  powder,  26  per  cent.;  dry  flesh  meal,  24  percent.;  ship's 
biscuits,  27  per  cent. — Jour.  Chem.  Soc,  July,  1885,  p.  827  ;  Zeit. 
physiol.  Chem.,  vol.  9,  211-221. 
