Amiyiarch,S'm-}    Diastasic  Power  of  Extract  of  Malt.  135 
mixture.  Experiment,  say  the  authors,  shows  that  1-484  gm.  of 
sulphate  of  copper  is  required  to  precipitate  1  gm.  of  uric  acid, 
hence,  1  ccm.  of  the  authors'  mixture  corresponds  to  1  mgm.  of 
uric  acid.  In  using,  the  phosphates  are  precipitated  from  the  urine 
by  carbonate  of  sodium  in  excess.  Of  the  filtered  liquor  20  ccm.  is 
taken,  and  into  this  the  reagent  is  introduced,  drop  by  drop,  until 
precipitation  and  flocculence  ceases.  The  authors  say  that  this 
reagent  is  very  sensitive. — Repert.  de  Phar.,  Jan.  10. 
THE  DETERMINATION  OF  THE  DIASTASIC  POWER  OF 
EXTRACT  OF  MALT. 
By  R.  A.  Cripps,  F.I.C. 
The  above  title  indicates  the  scope  of  this  brief  note  ;  it  is  not 
my  intention  to  enter  into  the  question  of  the  value  of  extract  of 
malt  as  a  nutrient,  but  simply  to  record  a  fact  of  considerable 
importance  in  connection  with  the  determination  of  its  value  as  a 
digestive  of  starchy  foods. 
Considerable  importance  is  attached  to  the  estimation  of  this 
digestive  power  ;  it  is  therefore  very  strange  that  published  results 
should  show  such  extraordinary  differences,  e.  g.,  Messrs.  Dunstan 
and  Dimmock  (who  were,  I  believe,  the  first  to  introduce  a  ready 
method  for  making  this  determination)  state  that  the  best  malt 
extracts  of  the  market  should  completely  digest  one-seventeenth  of 
their  weight  of  starch  in  several  (three?)  hours  (Pharm.  Journ.  [3], 
ix,  p.  733).  Carl  Jungk,  in  a  paper  in  the  American  Journal  of 
Pharmacy,  June,  1883,  and  Pharm.  Journ.,  xiv,  p.  104,  describes  a 
method  whereby  the  effect  of  malt  extract  upon  starch  mucilage  is 
tested  at  intervals  of  one  minute,  and  says  that  good  extract  of 
malt  should  convert  its  own  weight  of  starch  within  ten  minutes  at 
100°  F.  Later  still,  Pharm.  Journ.,  xv,  p.  236,  T.  S.  Dymond 
compares  the  two  methods  above  referred  to,  and  after  condemning 
Jungk's  method,  states  that  a  good  malt  extract  should  com- 
pletely digest  one-fifteenth  of  its  weight  of  starch  in  half  an  hour 
at  1400  F. 
I  think  the  key  to  these  divergencies  will  be  found  in  the  experi- 
ments recorded  below.  It  is  evidently  not  in  the  fact  that  malt 
extract  has  improved  during  late  years,  for  Mr.  Dymond's  experi- 
ments are  of  later  date  than  those  of  Juhgk.  Nor  do  I  think  that 
the  English-made  extracts  of  malt  are  inferior  to  those  of  foreign 
