AmAprii?i898arm'}    Recent  Literature  Relating  to  Pharmacy.  207 
greater  part  of  it  consists  of  the  inactive  body  arabin,  and  that 
diastase  is  a  protein  substance  more  resembling  albumose  than  any 
other  known  proteid.  Soluble  starch  can  be  prepared  from  starch 
either  by  boiling  with  water  or  with  2  per  cent,  potash  solution ;  in 
the  latter  case  acidulating  and  precipitating  with  95  per  cent,  alco- 
hol. Starch  treated  in  this  manner  gave  50  to  60  per  cent,  of  snow- 
white  soluble  starch,  which  dissolves  to  the  extent  of  3  per  cent,  in 
cold  water,  but  is  almost  insoluble  in  40  per  cent,  alcohol.  Soluble 
starch  is  no  doubt  none  other  than  the  first  product  in  the  hydro- 
lysis of  starch.  The  action  of  alkalies  on  starch  is  similar  to  that 
of  diastase,  and  alkalies,  if  slower,  have  greater  hydrolytic  power. 
— Hoppe  Seyler,  Zeits.  Physiol.  Chem.,  xxiv.,  174,  through  Pharma- 
ceutical journal,  February  19,  I 
PHYSIOLOGICAL  ACTION  OF  TANNIN  AND  GALLIC  ACID. 
Erich  Harnack  [Zeit.  Physiol.  Chem.y  1897,  24,  1 15-124)  reports 
that  by  administering  to  men  or  dogs  small  medicinal  doses  of  tan- 
nin or  gallic  acid,  the  quantity  of  gallic  acid  in  the  urine  is  very 
small,  but  the  greater  amount  is  contained  in  the  fpeces.  It  is  pro- 
bable that  some  of  the  gallic  acid  which  passes  into  the  urine  is 
decomposed,  and  traces  of  pyrogallol  are  found,  if,  in  searching  for 
it,  the  acidified  urine  has  been  evaporated ;  if  the  evaporation 
is  omitted,  pyrogallol  is  never  found.  Pyrogallol  is  highly  poison- 
ous, and  is  not  formed  in  the  organism. 
On  giving  larger  doses  of  gallic  acid,  more  passes  into  the  urine, 
especially  if  alkalies  are  given  as  well. 
By  feeding  on  free  tannin  none  passes  into  the  urine,  but  it  is 
found  after  giving  a  freshly-prepared  solution  of  tannin  in  alkali. 
For  the  isolation  of  tannin,  the  salting-out  method  by  saturated 
sodium-chloride  solution,  and  precipitation  by  solution  of  gelatin  or 
albumin  free  from  globulin,  is  recommended.  The  separation  of 
small  quantities  of  pyrogallol  and  gallic  acid  is  only  possible  when 
the  solubility  of  the  former  in  boiling  benzene  is  made  use  of. — 
Journal  of  the  Chemical  Society,  London,  February,  1 
PREPARATION  OF  SOLUBLE  STARCH  AND  STARCH  SOLUTION. 
Otto  Foerster  [Chem.  Zeit.,  1897,  21,  41)  states  that  to  prepare 
soluble  starch  a  paste  of  20  to  25  grammes  of  starch  with  water  is 
poured  in  a  thin  stream  into  200  to  300  c.c.  of  hot  water  containing 
