Am.  Jour,  Pharm. 
June,  1892, 
Reactions  of  Cocaine. 
317 
of  the  fabric  under  examination  is  made  to  imbibe  several  drops  of 
sulphuric  acid,  66°  B.;  after  5  or  10  minutes  add  5  cc.  distilled 
water,  heat  to  boiling,  decant  the  liquid,  add  gradually  concentrated 
solution  of  caustic  soda,  until  strongly  alkaline,  add  a  few  drops  of 
a  dilute  solution  of  extract  of  orchil,  and  heat  the  violet  liquid  for 
several  minutes  to  900,  when  if  cotton,  flax,  or  other  vegetable 
fibre  was  present,  it  will  be  decolorized  (on  exposure  to  the  air  the 
original  color  will  be  reproduced).  Should  the  violet  color  of  the 
liquid  remain  after  five  minutes'  heating,  the  fabric  is  free  from 
vegetable  fibre,  or,  at  most,  contains  but  a  minute  proportion  of 
the  same. 
REACTIONS  OF  COCAINE.1 
By  J.  C.  Stead. 
The  query  read  by  the  President  is,  What  is  the  best  chemical 
test  for  cocaine  salts  ?  "  To  attempt  to  answer  this  would  be 
presumptuous  on  my  part,  and  I,  in  reply,  can  only  enumerate  the 
characteristic  reactions  of  cocaine  salts  generally,  and  describe 
some  of  the  tests  which  have  been  proposed  for  their  identification. 
The  aqueous  solutions  of  the  freely  soluble  salts  of  cocaine  are 
precipitated  as  follows,  by — 
Carbonates  and  hydrates  of  ammonia,  the  alkalies  and 
alkali  earths,    white. 
Borax,   white. 
Picric  acid,   yellow. 
Tannin,  in  the  presence  of  hydrochloric  acid,   white. 
Meyer's  reagent,   white. 
Thresh' s  reagent,   brick  red. 
Iodine,   brick  red. 
Stannous  chloride,   white. 
Gold  chloride,   pale  yellow. 
Platinic  chloride,   yellowish  flesh. 
Mercuric  chloride,   white. 
They  are  not  precipitated  by  bicarbonates  or  tannin. 
With  the  ordinary  color  reagents  for  alkaloids,  viz.,  sulphuric 
acid,  sulphuric  acid  with  nitric  acid,  sulphuric  acid  with  sugar, 
sulpho-molybdic  acid,  nitric  acid,  hydrochloric  acid,  sulphuric  acid 
1  Read  before  the  Chemists'  Assistants'  Association  ;  reprinted  from  Phar. 
Jour,  and  Transactions,  April  30,  1892,  p.  902. 
