522 
CALCINATION  OF  MAGNESIA,  ETC. 
made  up  narcotine.  They  had  found  that  oxidation  of  mecOnine 
furnished  an  acid  containing  C20H10O10.  The  action  of  sodium 
amalgam  on  narcotine  furnished  a  basic  substance,  which  ap- 
peared to  be  cotarnine.  This  reaction  was  interesting,  because 
it  was  the  reverse  of  the  action  of  nitric  acid,  which  also  gave 
rise  to  cotarnine.    They  represented  cotarnine  by  the  rational 
formula    v  22r,  i°  6/     N,  for  the  action  of  nitric  acid  on  this 
L        °2H3  J 
body  furnished  an  acid  of  the  formula  C22H12O10,  and  on  dis- 
solving cotarnine  in  hydrochloric  acid  and  heating,  a  decomposi- 
tion ensued,  chloride  of  methyl  and  a  body  of  the  formula 
C22H13N08,  HC1  being  formed.  From  their  experiments  on  the 
decomposition  of  narcotine  by  soda  lime,  it  appeared  that  under 
these  circumstance  trimethylamine  was  formed,  which  had  been 
mistaken  for  propylamine  on  account  of  its  platinum  salt  con- 
taining the  same  per-centage  of  metal. 
Dr.  Redwood  remarked  that  he  entertained  doubts  as  to  the 
absence  of  meconic  acid  in  a  genuine  sample  of  opium.  He  had 
invariably  found  it  to  be  present  in  a  great  number  of  samples 
which  had  come  under  his  notice. 
Mr.  Morson  observed  that  meconic  acid  was  always  present 
in  opium,  unless  it  had  been  removed  by  lime  or  a  similar 
agent. — Chem.  News,  London,  May  10,  1862,  from  Proc.  Chem. 
Society. 
ON  THE  CALCINATION  OF  MAGNESIA  AND  THE  MEANS  OF 
TESTING  ITS  PURITY. 
By  M.  Amedee  Vee. 
Calcination  of  magnesia  is  an  operation  so  simple,  that  at 
first  sight  it  is  not  easy  to  comprehend  how  it  can  be  made  the 
subject  of  fresh  observations,  or  how  it  can,  in  any  case,  fail  to 
succeed.  It  is,  however,  constantly  made  evident  that  this  is 
not  the  case,  and  that  commercial  magnesia,  without  speaking 
of  its  impurities,  which  have  lately  been  much  insisted  upon,  is 
far  from  possessing  the  physical  properties  which  ought  to  per- 
tain  to  it ;  it  is  dense,  granular,  very  slightly  attackable  by  di- 
luted acids,  and  is  with  difficulty  held  in  suspension  in  water. 
No  way  of  avoiding  these  defects  has  hitherto  been  known  ex- 
