650 
The  Relative  Value  of  Proteins. 
\  Am.  Jour.  Pharm. 
I      Sept.,  1921. 
discrepancies  seem  to  be  due  to  the  different  basal  diets  used  by  the 
various  investigators.  The  results  of  McCollum  and  associates  are 
very  contradictory ;  they  believe  the  inadequacy  depends  on  improper 
mineral  supply.  Insufficiency  of  vitamin  supply  is  a  contributory 
cause.  Osborne  and  Mendel  tried  not  only  the  whole  grain,  but  also 
different  commercial  articles  produced  by  milling,  such  as  wheat 
flour,  bran,  embryo.  Normal  growth  followed  the  use  of  whole 
grain,  and  very  little  difference  was  noticed  among  the  various  - 
grains. 
In  all  cases  animals  kept  for  long  periods  produced  small  or  no 
litters  of  young;  their  health  had  thus  been  impaired.  This  loss  of 
reproductive  power  has  been  observed  by  all  workers  if  cereals 
supply  the  sole  protein. 
Wheat  embryo  contains  the  albumin,  and  is  fully  adequate ;  bran 
proteins  are  even  of  superior  value.  Wheat  flour,  pearl  barley,  and 
maize  meal  are  not  adequate. 
The  milling  process  thus  removes  "good"  protein.  Wheat  flour, 
etc.,  does  not  contain  enough  total  protein,  but  in  the  experiments 
the  total  was  made  up  by  adding  gluten.  The  endosperm  of  the 
grain  will  only  furnish  protein  for  maintenance. 
SUPPLEMENTS  TO  THE  PROTEINS  OF  CEREALS. 
Neither  men  nor  animals  consume  the  whole  cereal,  and  as  the 
endosperm  does  not  supply  enough  protein  in  quantity  or  quality, 
it  must  be  supplemented.  The  protein  ratio  of  1 :  10  needs  to  be 
increased  up  to  1 :  5.  Animal  proteins  form  the  best  supplements. 
Lactalbumin  was  shown  by  Osborne  and  Mendel  to  be  the  best  sup- 
plement, but  for  some  peculiar  and  unaccountable  reason  other 
workers  do  not  find  this  protein  so  good.  Meat,  milk,  eggs  are 
almost  equally  efficient,  but  casein  is  of  less  value.  In  the  case  of 
maize  meal  and  milk  at  least  an  equal  part  of  skim  milk  is  needed; 
this  gives  30  per  cent,  of  the  mixture  of  proteins  as  derived  from 
milk.  Yeast  protein  and  peanut  flour  are  good  supplements.  Cot- 
tonseed and  pea  are  inferior,  whilst  products  like  distillers'  grain  or 
vegetable  albumin,  which  is  derived  from  grain,  are  of  little  value. 
The  best  supplementing  proteins  are  thus  those  containing  the  hex- 
one  bases,  tryptophan,  etc.  which  are  low  in  amount  in  the  cereals. 
To  produce  normal  or  rapid  growth  it  is  possible  that  it  may  be 
more  economical  to  use  "good"  proteins,  which  are  more  expensive 
than  "bad"  proteins. 
