520 
COLOR  TESTS  FOR  STRYCHNIA,  ETC. 
nia.  Feeling  that  my  time  would  not  be  wasted  in  repeating 
his  experiments,  and  if  possible  extending  them  to  substances 
not  included  in  his  list,  I  possessed  myself  (partly  by  the  kind 
assistance  of  Mr.  Morson)  of  all  the  alkaloids  and  similar  active 
principles  which  could  be  obtained,  and  tested  them  in  the  same 
way.  To  Mr.  Jenkins's  list,  some  of  which  I  was  not  able  to 
procure,  I  succeeded  in  adding  as  many  as  sixteen  new  sub- 
stances. None  of  these  gave  the  characteristic  colored  reac- 
tions of  strychnia,  nor  any  succession  of  colors  any  way  resem- 
bling them,  so  that  I  am  now  in  a  condition  to  assert  that 
strychnia  stands  alone  among  sixty-six  analogous  compounds  in 
the  reactions  which  it  gives  with  sulphuric  acid  followed  by  the 
bichromate  of  potash. 
Mr.  Jenkins  (as  will  be  seen  in  the  table  published  by  him  in 
the  Chemical  News  for  October  6,  I860,)  arranges  his  reactions 
in  two  columns.  The  first  column  displays  the  effect  produced 
by  strong  sulphuric  acid ;  the  second,  the  changes  of  color 
caused  by  the  addition  to  the  acid  solution  of  the  bichromate  of 
potash.    [See  page  527  for  the  paper  of  Mr.  Jenkins.] 
Now  this  table  affords  an  excellent  illustration  of  the  absence 
of  method  and  logical  arrangement.  The  substances  operated 
on  evidently  took  their  places  as  they  chanced  to  come  to  hand. 
Strychnia  itself  has  to  be  sought  out ;  and  substances  which  give 
colored  reactions  with  sulphuric  acid,  find  themselves  in  contact 
with  others  that  give  a  negative  result. 
And  yet  the  table  seems  to  court  the  attention  of  lovers  of 
method  and  logical  order.  It  is  almost  impossible  to  keep  one's 
hands  off  it.  At  least  one  would  like  to  place  the  substances 
which  are  not  colored  by  sulphuric  acid  by  themselves,  and  those 
that  are  colored  also  by  themselves.  I  have  undertaken  this 
work  of  tabulation,  and,  on  inspecting  the  result,  am  seized 
with  the  same  desire  to  resume  the  work  of  arrangement.  In 
both  groups  their  are  substances  which  yield  with  bichromate 
of  potash  the  same  colors.  Why  should  not  these  similar  reac- 
tions be  bracketed  together  ?  This,  accordingly,  I  have  carried 
into  effect,  and  the  result  is  a  splitting  up  of  the  fifty  substances 
into  several  groups  of  such  moderate  dimensions,  that  a  man 
given  to  tabular  analysis  can  scarcely  resist  the  additional 
temptation  to  try  whether  some  modification  of  the  tests  them- 
