Am.  Jour  Pharni.) 
June,  1883.  j 
Extract  of  Malt. 
297 
the  view  of  convincing  myself  of  the  exactness  of  this  method,  which 
may  be  approximately  proven  by  coagulating  the  albumen  by  boiling. 
This  last  method  is  never  exact,  since  malt  contains  some  nitrogenous 
matter  which  is  not  coagulated  by  heat. 
The  average  amount  of  niti'ogenous  matter  contained  in  extract  of 
malt  of  the  consistency  of  honey  is  3  to  3*25  per  cent.  A  well 
prepared  extract  of  malt  produces,  with  cold  water,  a  faintly  turbid 
solution,  which  becomes  much  clearer  if  carefully  heated  to  150°F. 
The  above  described  determinations  with  extract  of  malt  furnish 
the  proof  as  to  whether  the  preparation  is  of  good  quality  or  is 
worthless. 
Simple  Estimation  of  Dextrin,  Sugar  and  Glycerin. — A  polariscope 
is  not  always  available,  and  if  at  hand  the  instrument  must  first  be 
tested  with  pure  crystallized  malt  sugar ;  the  separation  of  the  sugar 
from  dextrin,  and  the  decolorization  of  the  liquid  are  tedious  opera- 
tions. For  these  reasons  I  use  this  method  only  occasionally  for 
controlling  the  results ;  but  the  following  short  process  will  be  found 
to  give  quite  accurate  results. 
Weigh  from  2  to  5  grams  of  extract  of  malt ;  mix  with  20  grams 
of  dry  sand  which  has  been  previously  washed  with  hydrochloric  acid 
and  water,  and  dry  this  mixture  in  an  air-bath  at  100°  C.  until  it 
ceases  to  lose  weight.  The  loss  of  weight  represents  amount  of 
water. 
Transfer  the  mixture  into  a  small  glass  percolator  (glass  syringe) 
supported  by  a  wire  stand  of  such  a  size  that  the  entire  apparatus  may 
be  weighed  on  an  analytical  balance.  Dry  thoroughly  in  an  air-bath 
and  weigh.  Now  percolate  w^ith  strong  ether,  evaporate  the  percolate 
and  dry  the  residue;  its  weight  indicates  the  resin  of  hops.  The 
apparatus  is  also  dried  in  the  air-bath  and  weighed ;  the  loss  in  weight 
shows  likewise  the  resin  of  hops. 
Then  percolate  with  a  mixture  of  two  volumes  of  absolute  alcohol 
and  three  volumes  concentrated  ether  until  a  drop  of  the  percolate 
heated  on  a  platinum  foil  will  not  char.  The  loss  of  weight  after 
drying  in  air-bath  represents  glycerin.  A  mixture  of  chloroform  and 
alcohol  cannot  be  used  as  a  solvent  for  glycerin,  as  the  malt  sugar  is 
somewhat  soluble  therein. 
Exhaust  the  residue  completely  with  stronger  alcohol ;  dry  and 
weigh.    The  loss  of  Aveight  gives  amount  of  sugar. 
The  balance,  after  subtracting  the  weight  of  sand  is  dextrin  and 
