Am.  Jour.  Pharm.l 
June,  1884.  / 
Constituents  of  White  Agaric. 
373 
that  of  cold  water  j  and  if  this  greater  absorptive  power  be  satisfied 
by  addition  of  more  iodine,  then  the  blue  color  is  not  destroyed  even 
by  boiling.  The  author  considers  the  blue  color  to  be  simply  due  to 
the  solution  of  iodine  in  potato-starch,  just  as  violet  and  brown  colors 
are  obtained  on  solution  in  chloroform  and  water  respectively. 
Potato-  and  arum-starch  yield  blue  colorations,  wheat-  and  rice-starch 
yield  violet,  but  after  boiling  they  also  are  turned  blue  by  iodine. 
Starch-grains  have  a  greater  attraction  for  iodine  than  unorganized 
starch ;  thus  a  cold  clear  solution  prepared  from  crushed  starch-grains 
and  colored  blue  by  iodine,  is  completely  decolorized  by  adding  whole 
starch-grains.  Similarly,  it  is  shown  that  starch-grains  attract  iodine 
more  energetically  than  dextrin,  the  red  solution  being  decolorized,  and 
the  starch -grains  turning  blue. 
In  conclusion,  soluble  starch,  starch -paste,  granulose,  amidulin  and 
amylodextrin  are  identical,  i.  e.,  give  identical  reactions,  as  also  are 
erythrogranulose,  erythrodextrin  and  dextrin. — Jour.  Chem.  Soc, 
May,  1884,  p.  575,  from  Monatsh.  Chem.,  vol.  4. 
CONSTITUENTS  OF  WHITE  AGARIC. 
By  E.  Jahns. 
Although  the  larch  agaric  (Polyporus  officinalis)  has  been  investi- 
gated by  more  than  one  chemist,  conflicting  statements  concerning  its 
constituents  still  exist.  The  author,  with  the  view  of  clearing  up  the 
question,  has  re-investigated  this  plant.  By  extraction  with  hot  strong 
alcohol  it  yielded  about  18  per  cent,  of  a  crystalline  acid  melting  at 
about  139°,  and  easily  soluble  in  alcohol,  glacial  acetic  acid,  and  tur- 
pentine ;  less  soluble  in  ether,  and  nearly  insoluble  in  chloroform,  ben- 
zene and  cold  water.  The  acid  is  dibasic,  forming  normal  salts  with 
the  alkali  metals,  which  are  easily  soluble  in  water,  and  acid  salts  which 
are  only  slightly  soluble ;  with  the  majority  of  the  metals,  it  forms 
insoluble  salts,  which  are  precipitated  in  the  amorphous  state  from 
aqueous  solutions.  Analysis  showed  that  agaricic  acid  was  a  homo- 
logue  of  malic  acid,  represented  by  the  formula  C16H30O5H2O.  On 
oxidation  with  nitric  acid,  it  is  converted  into  succinic  and  butyric 
acids.  The  principal  salts  are  described  in  the  paper.  This  acid  is 
identical  with  the  "  agaricic  acid  "  of  Fleury,  the  "  laricin 99  of  Mar- 
tius ;  and  the  substances  named  by  Schoonbroodt  "  agaricin "  and 
"  pseudo-wax "  by  Trommsdorff  are  probably  the  same  acid  in  an 
