64  Gleanings  from  the  Foreign  Journals.  {Am'FJe°buri8^6.arm' 
color,  to  blue  color,  usually  obtained,  is  due  to  impurity.  Cryptopia 
gives  a  blue  color.  Now  from  water  solution  of  sulphates,  chloroform 
dissolves  and  extracts  papaverina,  narcotina  and  thebaina,  (narceina  ?), — 
leaving  the  morphia  in  the  water  solution. 
In  connection  with  the  inquiry  as  to  the  effect  of  concentrated 
sulphuric  acid  upon  morphia,  it  is  interesting  to  note  the  remarkable 
power  which  cane  sugar  has,  as  a  third  body,  in  this  reaction. 
Schneider's  test*  gives  a  purple-violet  color  of  such  intensity  that  it  is 
not  exceeded  in  delicacy  by  any  other  test,  (others  being  probably  more 
characteristic).  As  to  the  organic  products  of  these  reactions,  having 
stated  that  chemists  were  generally  unacquainted  with  the  products  of 
oxidation  of  organic  compounds  as  they  occur  in  the  "  color  tests,"  I 
ought  to  refer  to  at  least  one  research  upon  morphia,  doubtless  in  the 
direction  of  the  light  desired.  C.  R.  A.  Wright  has  not  labored  so 
patiently  among  the  alkaloids,  in  the  service  of  synthesis,  without  some 
benefit  to  analysis,  as  well.  Thus,  he  gives  the  formula  (not  fully 
confirmed)  of  the  blood  red  liquid  formed  by  action  of  nitric  acid  and 
silver  nitrate  upon  morphia,  as  C2iH20N3O13.t 
University  of  Michigan^  January \  1876. 
GLEANINGS  FROM  THE  FOREIGN  JOURNALS. 
BY  THE  EDITOR. 
Examination  of  Olive  Oil. — E.  Kopp  calls  attention  again  to  the 
following  simple  method,  which  depends  upon  the  conversion  of  the 
oil  into  solid  elaidin  by  means  of  nitrous  acid.  Ten  volumes  of  the 
oil  and  one  volume  of  ordinary  nitric  acid  are  poured  into  a  test-glass, 
and  a  few  pieces  of  copper  wire  are  added,  whereby  nitric  oxide  is 
evolved,  which,  with  the  nitric  acid,  yields  nitrous  acid.  As  soon  as 
the  gas  bubbles  passing  through  the  oil  become  numerous,  the  acid  and 
oil  are  intimately  mixed  by  stirring  with  a  glass  rod.  After  about  five 
minutes,  the  mixture  is  again  made  by  continuous  stirring,  and  then  set 
aside  in  a  cool  place  of  120  to  150  C.  (540  to  590  F.)  The  oil  sepa- 
rates again  from  the  acid,  with  a  blue  color  from  the  presence  of  cop- 
per nitrate,  but  soon  begins  to  congeal,  the  more  rapid  in  proportion 
to  the  purity  of  the  olive  oil,  the  elaidin  being  not  only  solid,  but  like- 
*  "Am.  Journ.  Phar.,"  xlv,  (1873),  545  5  xlvi,  (1874),  558.  "  Zeitsch.  f.  analyt. 
Chemie,"  xii,  (1873),  2l8- 
f  "Jour.  Chem.  Soc,"  1873,  p.  1088. 
