236 
Laboratory  Notes. 
Am.  Jour.  Pharm. 
May,  1886. 
A  quantitative  test  was  made,  according  to  test  three  (3),  with  the 
following  results: 
No.  1  contained  9.77  per  cent,  of  tartaric  acid. 
"  2      "        19.42      "        "      "  '* 
u    3         u  u  u 
The  acid  tartrate  of  potassium,  formed  on  mixing  the  saturated 
solutions  of  potassium  acetate  and  the  magnesium  citrate,  was  tested 
for  tartaric  acid  in  the  following  manner:  The  bitartrate  of  potassium 
was  neutralized  with  sodium  hydrate,  forming  the  soluble  sodium  and 
potassium  tartrate ;  then  silver  nitrate  was  added,  forming  silver  tar- 
trate. To  this  precipitate  one  drop  of  ammonium  hydrate  was  added 
to  redissolve  the  silver  tartrate,  and  the  solution  was  heated  slowly, 
upon  which  the  silver  mirror  was  formed  on  the  sides  of  the  test  tube. 
Potassium  was  tested  for  in  two  of  the  specimens,  but  with  nega- 
tive results. 
A  test  was  also  made  for  sulphuric  acid,  and  the  three  samples 
gave  the  precipitate  with  barium  chloride. 
The  amount  of  sulphuric  acid  was  estimated  in  numbers  "one" 
and  "  two,"  with  the  following  results  : — 
No.  1  contained  7*07  per  cent,  of  sulphuric  acid. 
No.  2      "  .699    "  " 
No.  3      "      a  small  trace. 
Another  sample  of  the  salt  was  prepared  by  the  writer  according 
to  the  Pharmacopoeia,  with  a  fair  result,  and  answered  all  the  tests 
required  by  the  U.  S.  P. 
Diastase. — By  E  Botjrquelot  (J.  Pharm.  [5],  xi,  367-372). — 
Diastase  is  widely  distributed  in  nature,  both  in  animals  and  plants. 
Most  physiologists  admit  that  malt  diastase  and  that  of  human  saliva 
determine  the  saccharification  of  starch,  of  glycogen,  and  of  certain 
dextrins;  but  some  maintain  that  these  compounds  possess  other 
properties.  The  author,  however,  shows  that  the  inversion  of  cane- 
sugar  ascribed  to  the  action  of  saliva  diastase  is  really  due  to  the  in- 
vertin  secreted  by  microphytes  present  in  the  saliva;  the  same  action 
caused  by  malt  diastase  is  due  to  invertin  secreted  by  fungoid  growths 
which  can  be  found  on  the  malt  grains.  The  author  maintains  that 
all  the  diastases  considered  are  identical. — Jour.  Chem.Soc,  1885,  p.  927. 
