Axovlmbe?!mt}    Notes  on  the  Mydriatic  Alkaloids,  515 
were  crystals  obtained  by  the  reagent  from  a  i-iooth  or  more 
dilute  solution  of  this  alkaloid. 
This  reaction,  therefore,  serves  to  discriminate  atropine  and 
hyoscyamine  from  hyoscine,  at  least  from  the  preparation  under 
examination. 
The  Bromine  reagent  may  be  very  satisfactorily  applied  to  atro- 
pine and  hyoscyamine,  and  their  salts,  in  the  solid  state.  If  a 
minute  portion  of  either  alkaloid  be  touched  with  a  small  drop  of 
the  reagent,  it  is  immediately  converted  into  a  mass  of  crystals,  con- 
sisting of  rough  needles,  twig-like  masses  and  bright  yellow  plates. 
The  residue  from  one  drop  of  a  i-ioooth  solution  of  the  alkaloids 
yields  with  the  reagent,  a  mass  of  crystals  of  the  usual  forms ;  and 
the  residue  from  a  drop  of  a  1-1  ooooth  solution,  gives  a  very  sat- 
isfactory deposit  of  crystalline  needles  and  granules. 
This  reaction,  as  in  the  case  of  solutions  of  the  alkaloid,  will 
manifest  itself  in  the  presence  of  comparatively  large  proportions  of 
foreign  matter.  Thus,  if  a  drop  of  a  i-ioooth  solution  of  the 
alkaloid  be  treated  with  a  drop  of  ordinary  urine,  and  the  mixture 
evaporated  to  dryness,  the  residue  will  yield,  under  the  reagent,  a 
very  satisfactory  crystalline  reaction,  although  the  proportion  of 
urine  solids  to  the  alkaloid  present  is  about  50  :  I.  Crystals  may 
be  obtained  from  even  a  much  less  quantity  of  the  alkaloid  mixed 
with  this  amount  of  urine  solids. 
If  the  Bromine  reagent  be  applied  to  a  minute  drop  of  a  syrupy 
solution  of  hyoscine,  it  is  immediately  converted  into  a  mass  of  red- 
dish-yellow globules,  which  soon  change  to  bold  groups  of  faintly 
yellow  crystals,  these  being  quite  different  in  form  from  the  crystals 
obtained  from  the  other  two  alkaloids. 
The  residue  from  a  drop  of  a  i-iooth  solution  of  hyoscine  yields, 
under  the  reagent,  a  mass  of  yellow  globules,  which  soon  become 
converted  into  groups  of  bold  crystals.  From  the  residue  from  a 
i-ioooth  solution  of  this  alkaloid  no  crystals  were  obtained,  the 
precipitate  consisting  alone  of  oily  drops. 
(4)  Picric  Acid. — A  drop  of  a  I-iooth  solution  of  atropine, 
when  treated  with  a  drop  of  an  alcoholic  solution  of  this  reagent, 
yields  a  voluminous  yellow  precipitate,  which  slowly  becomes  con- 
verted into  minute  yellow  drops.  If,  however,  the  mixture  be 
stirred  with  a  glass  rod,  it  quickly  yields  beautiful  groups  of  yellow 
crystals,  as  figured  in  Micro- Chemistry  of  Poisons.    PI.  xiii,  Fig.  1. 
