318  Lloyd  Reaction  as  Applied  to  Heroin.  {^i^;i^x^ 
chromate  crystals ;  alcohol,  purified  by  distillation  in  a  partial 
vacuum  at  a  temperature  between  350  C.  and  480  C,  having  a  specific 
gravity  of  0-820  at  150  C,  representing  94  per  cent,  of  alcohol  by 
volume ;  heroin,  Bayer's  pure,  white  crystals,  having  a  melting  point 
of  1630  C. ;  veratrin,  Powers  &  Weightman's  white  amorphous 
powder,  having  a  melting  point  of  1370  C;  hydrastin,  Merck's  pure, 
white,  crystalline  alkaloid,  having  a  melting  point  of  2360  C. 
SOLUTIONS. 
Separate  solutions  of  each  alkaloid,  in  alcohol,  were  made  of  such 
strength,  so  that  1  c.c.  contained  3  mgms.  of  hydrastin  and  5  mgms. 
each  of  heroin  and  veratrin. 
The  smaller  proportions  were  obtained  by  appropriately  diluting 
the  original  solutions  with  alcohol,  so  that  o-l  c.c.  to  0-9  c.c.  would 
contain  the  desired  quantity  of  the  alkaloids. 
MIXTURES. 
The  mixtures  were  made  by  measuring,  from  separate  burettes, 
the  volume  of  alcoholic  solution  containing  the  desired  weight  of 
the  alkaloid,  into  small,  white  porcelain  dishes,  and  allowing  spon- 
taneous evaporation  to  occur  in  an  ice  chest  at  150  to  20°  C.  In 
this  manner  the  thoroughly  mixed  alkaloids  were  deposited  in  a 
small  area,  except  in  those  cases  in  which  the  volume  of  the  mixture 
measured  over  1  c.c. 
As  pointed  out  in  my  previous  paper  on  "  The  Lloyd  Reaction 
for  Morphine  and  Other  Alkaloids,"8  it  is  very  important  to  have 
the  entire  alkaloidal  residue  distributed  over  a  very  small  area  to 
obtain  the  best  results. 
TEMPERATURE. 
Temperature  plays  an  important  role  in  the  Lloyd  reaction  as 
indicated  by  Williams.  The  temperature  employed  in  my  experi- 
ments in  applying  the  reagents  was  room  temperature  between  250 
and  300  C.  ;  also  between  8o°  and  900  C.  It  was  found  that  on 
gradually  increasing  the  temperature  from  300  to  1000  C,  the  play 
of  colors  was  produced  more  rapidly  and  increased  in  intensity,  the 
best  results  being  obtained  between  8o°  and  900  C.  The  latter 
temperature  was  maintained  by  the  use  of  a  water-bath. 
When  applying  the  test  at  a  temperature  between  8o°  C.  and 
900  C,  the  dish  containing  the  alkaloidal  residue  was  placed  on  the 
