COLOR  TEST  FOR  THE  DETECTION  OF  STRYCHNIA.  387 
come  a  source  of  error,  while  on  the  other  hand  a  solution  of  that 
salt  in  sulphuric  acid  (1  gr.  to  2000  grs.)  exhibits  a  light  green 
color,  which  is  less  liable  to  be  confounded  with  the  colors  de- 
veloped during  the  application  of  the  test. 
The  test  solution  of  strychnia  was  made  with  the  crystallized 
alkaloid  dissolved  by  the  intervention  of  sulphuric  acid  in  water  ; 
each  drop  of  the  solution  representing  the  soir^^  of  a  grain  of 
the  alkaloid.  A  pipette  was  used  capable  of  dropping  one- 
sixth  of  a  drop.  The  drop  here  alluded  to  was  carefully  ascer- 
tained to  be  equal  to  1-2  minim.  So  that  the  pipette  drop  was 
equal  to  0*2  minim.  The  dilutions  were  prepared  from  this  nor- 
mal solution.  The  following  table  will  exhibit  the  different  strych- 
niated  solutions  prepared  for  experiment,  with  amounts  of  strych- 
nia contained  in  each  ^th  drop,  and  the  comparative  results  ob- 
tained by  the  application  of  the  different  test  agents  employed : 
Amt.  of  strychnia  contained  in  ]4, 
drop  ot  eaeli  solution. 
KO,2Cr03  &  S04H 
test  (solid). 
Cr03  and  S04H 
test  (1  500). 
KO,Mt.207  and 
SOU!  test  (1  
2000). 
1  drop  1  X  50,0Cf0  =  1-100,000. 
Color  reaction 
distinct  and  well 
defined. 
Color  reaction 
very  fine  and  dis- 
tinct. 
Reaction  very 
brilliant  and  du- 
rable. 
•1  drop  ^  X  50,000  =  1-300,000. 
Reaction  weak 
and  evanescent. 
Colors  fine  and 
distinct. 
Colors  brilliant 
and  reaction  dis- 
tinct. 
\  drop        50,000  =  1-600,000. 
No  reaction. 
Colors  still  de- 
finable, but  weak. 
Reaction  dis- 
tinct and  colors 
fine. 
•i  drop       50,000  —  1-900,000. 
No  reaction. 
Reaction  laint, 
but  succession  of 
colors  well  de- 
fined. 
-i  drop  ^y*  50,000  =  1-1,200,000. 
Reaction  very 
faint. 
It  will  be  seen  on  inspecting  the  above  table  that  the  limit  of 
positive  recognition  by  the  bichromate  of  potassa  and  sulphuric 
acid  test  may  be  placed  at  tuoooo^  ^^^^^  of  the  chromic  acid,  &c., 
test,  at  -g-oo^ooo^  ^"^^  that  of  the  permanganate  at  yooooo-  The 
manner  in  which  the  experiments  were  conducted  may  be  stated 
as  follows  : 
The  one-sixth  of  a  drop  of  the  normal  solution  was  dropped 
from  the  pipette  upon  a  warmed,  highly  glazed  porcelain  sur- 
face, and  allowed  to  evaporate  spontaneously.  The  thin  circular 
film  which  the  drop  left  was  readily  perceived  by  the  aid  of  a 
good  light.    It  was  found  that  the  alkaloid  contained  in  the 
