454 
Occurrence  of  Amygdalin,  etc. 
f  Am.  Jour.  Phariu  j 
\     Oct.  1, 1872. 
ON  THE  OCCURRENCE  OF  AMYGDALIN  AND  THE  GENERA- 
TION OF  HYDROCYANIC  ACID. 
By  S.  Henschen,  of  Upsala.* 
The  author  has  instituted  a  number  of  experiments,  in  which  he 
proved  the  presence  of  hydrocyanic  acid  by  paper  dipped  in  tincture 
of  guaiacum  and  solution  of  sulphate  of  copper,  carefully  avoiding 
ammoniacal  vapors.  If  the  paper  turned  blue,  the  flask  was  placed 
into  warm  water  and  a  current  of  air  passed  through  its  contents  and 
a  refrigerated  glass  tube,  the  U  bend  of  which  contained  a  few  drops 
of  weak  alkali ;  or  the  flask  was  heated,  and  the  vapors  were  passed 
first  through  a  Liebig's  condenser  and  afterwards  through  a  glass  tube 
arranged  as  before.  The  liquids  in  the  tube  were  afterwards  used  for 
the  production  of  Prussian  blue  and  sulphoeyanide  of  iron,  in  the 
well-known  manner. 
Amygdalin  treated  with  the  meal  of  peas  and  of  rye  yielded  hydro- 
cyanic acid,  but  none  with  finely  sifted  wheat  flour. 
Sweet  almonds  yielded  hydrocyanic  acid,  10  grm.  gave  a  faint  re- 
action, 30  grm.  distinct ;  they  therefore  contain  a  minute  quantity 
of  amygdalin. 
Amygdalus  nana,  Lin.  The  seeds,  pericarp,  leaves,  branches  and 
buds  yielded  hydrocyanic  acid. 
Pyrus  malus,  Lin.  1  to  2  grm.  of  seeds  yielded  HCy ;  none  was 
obtained  from  leaves,  buds  or  branches. 
Pyrus  communis,  Lin.    The  seeds  yielded  HCy,  the  leaves  none. 
Pyrus  Cydonia,  Lin.  The  isolation  of  the  HCy  generated  from 
the  seeds  is  with  difficulty  effected  from  the  mucilaginous  liquid. 
Sorbus  aucuparia,  Lin.  The  yield  of  HCy  from  the  seeds  was  not 
as  large  as  might  have  been  expected  from  the  large  yield  from  the 
bark. 
Sorbus  latifolia,  Lin.  HCy  was  obtained  from  0*5  grm.  seeds,  and 
17  grm.  buds  ;  none  from  sarcocarp,  leaves,  branches  or  bark. 
Crataegus  Virginica,  (?).    No  HCy  from  any  part  of  the  plant. 
Negative  results  were  likewise  obtained  with  the  fruit  of  Rosa 
tomentosa,  separated  from  the  hip  ;  with  the  seeds  of  the  lemon  and 
melon,  and  with  allspice.  Indications  of  HCy  were  obtained  from 
20  grm.  of  vetches  ( Vicia). 
*  Condensed  from  Neues  Jahrbuch  fur  Pharmacie,  1872,  July  1 — 13 — Up- 
aala  Lakare  forenings — Forhandl.  iv,  No.  4. 
