<SLm  Jour.  Pharm.  ) 
Jan.  1,  1872.  J 
Vanillic  Acid. 
25 
of  different  poisons  was  mixed  with  pieces  of  flesh  selected  for  the 
purpose,  and  then  tested  for.  The  results  obtained  showed  that  in 
many  cases  the  whole  quantity  of  the  poison  mixed  with  the  flesh  was 
recovered,  and  in  most  cases  the  greater  part  was  found.  The  results 
gave  general  satisfaction,  especially  on  account  of  the  great  purity  of 
the  alkaloids  obtained  from  the  chloroform,  so  that  the  reactions  for 
Identifying  them  could  be  made  at  once. — Journ.  App.  Chem.,  Dec, 
1872. 
VANILLIC  ACID.* 
By  P.  Carles. 
After  being  preserved  for  a  certain  time  vanilla  generally  becomes 
covered  with  crystalline  needles.  As  this  crystallization  is  considered 
to  be  a  mark  of  good  quality,  sometimes  it  is  sought  to  impart  it  to 
inferior  vanilla,  and  this  is  done  by  simply  putting  some  of  the  crys- 
tals already  formed  into  the  case  containing  it.  The  chemical  compo- 
sition of  this  efflorescence  does  not,  however,  appear  to  be  perfectly 
understood. 
Formerly,  and  the  error  has  been  repeated  in  recent  works,  Vogel 
asserted  that  it  consisted  of  benzoic  or  cinnamic  acid  ;  Wittstein 
thought  it  to  be  coumarin.  M.  Vee,f  comparing  the  melting-points 
of  these  various  substances,  detected  the  error  and  showed  that  it  was 
a  peculiar  acid.  About  the  same  time,  M.  GobleyJ  investigated  the 
-chemical  characters  of  these  crystals,  compared  them  with  coumarin, 
and  proposed  for  them  the  name  vanillin,  or  aromatic  principle  of 
vanilla.  Later,  in  Germany,  Stokkebye§  took  up  the  subject.  He 
fixed  the  melting-point  at  82°  C,  instead  of  76°  C.  (Gobley),  or  78° 
O.  (Yee),  and  in  virtue  of  its  acid  properties  called  it  vanillic  acid. 
Finally,-  while  Gobley  had  attributed  to  it  the  formula  C20H6O4,  Stok- 
kebye  represented  it  by  C34H22O20.||  These  differences  in  the  formulae 
and  melting-points  attributed  to  it  seemed  to  show  that  even  if  their 
authors  examined  the  same  crystals,  they  were  at  least  not  of  equal 
purity.  M.  Carles  was  therefore  induced  to  undertake  the  present 
investigation. 
Instead  of  extracting  the  vanillic  acid  directly  from  the  vanilla,  M. 
*  Abstract  of  paper  in  L'Union  Pharmaceatique,  xiii,  294. 
f  Journ.  de  Pharm.  et  de  Cliimie,  [3]  xxxiv,  412. 
%  Ibid.,  404. 
I  Zeitschrif't  fur  Chemie,  1865,  p.  467. 
'jj  These  formulae  are  according  to  the  old  notation, 
