410        Recent  Literature  Relating  to  Pharmacy.  {AmAugurs'tff8M.m' 
The  number  found  is  subtracted  from  5  and  the  result  represents 
the  number  of  cubic  centimeters  of  normal  KOH  solution  that  were 
required  to  neutralize  the  nitric  acid  necessary  to  form  1  gramme  of 
bismuth  subnitrate.     1  c.c.  of  KOH  expresses  1,000th  part  of  the 
equivalent  of  "^2<^5  =  15?  =  54,  i.  e.,  0-054  gramme.    This  multi- 
2  2 
plied  by  100  gives  the  percent,  of  bismuth  subnitrate. — Apoth.  Zeit.r 
1898,  p.  318. 
STARCH  FERMENTS. 
Wyatt  Wingrave  has  made  a  comparative  examination,  both 
chemically  and  clinically,  of  a  number  of  preparations  of  starch 
ferments  easily  obtainable.  His  attention  was  confined  to  the  vege- 
table or  diastatic  ferments,  which,  he  remarks,  are  easily  obtained, 
stable,  reliable  in  action  and  economical  in  price.  The  best-known 
samples  are  malt-diastase  and  taka-diastase.  His  conclusions  may 
thus  be  briefly  summarized  :  (1)  That  of  the  commercial  starch  or 
diastatic  ferments  taka-diastase  is  the  most  powerful  and  the  most 
reliable,  since  it  is  more  rapid  in  its  action— i.  e.}  it  will  convert  a 
larger  amount  (of  starch)  in  a  given  time  than  will  any  other  amyl- 
olytic  ferment.  (2)  That  taka-diastase  seems  to  be  less  retarded  in 
its  digestive  action  by  the  presence  of  the  organic  acids  (butyric, 
lactic,  acetic),  and  also  by  tea,  coffee  and  alcohol,  than  are  saliva  and 
the  malt  extracts.  (3)  That  all  mineral  acids,  such  as  hydrochloric, 
etc.,  quickly  stop  and  permanently  destroy  all  diastatic  action  if  allowed 
sufficient  time  and  if  present  in  sufficient  quantities.  (4)  That  taka- 
diastase  and  malt-diastase  have,  like  ptyalin,  no  action  upon  cellu- 
lose (uncooked  starch). —  The  Lancet,  1898,  No.  3897,  p.  1251. 
STROPHANTHIN  AND  STROPHANTHIDIN. 
Thorns  was  the  first  to  prepare  pure  strophanthin,  and  at  the 
same  time  to  show  that  the  difficulty  of  previous  authors  in  obtain- 
ing a  pure  product  was  due  to  the  presence  of  cholin  and  trigonellin 
in  the  seeds  of  strophanthus.  Several  other  authors,  viz.:  Kohn  and 
Kulisch  and  Feist  (Ber.  d.  D.  Cliem.  Ges.,  1898,  p.  534),  have  fur- 
ther contributed  to  our  knowledge  of  these  principles.  Kohn  and 
Kulisch  have  confirmed  the  results  of  Arnaud,  who  proposed  the 
formula  for  strophanthin  as  being  C31H48012.  Feist,  however,  gives 
the  formula  for  the  same  substance,  when  dried  over  sulphuric  acid 
