COLOR  TESTS  FOR  STRYCHNIA,  ETC. 
521 
selves,  or  some  additional  tests,  or  both  together,  may  not  lead 
to  a  successful  separation  and  elimination  of  each  and  all  the 
substances  contained  in  the  table.*  I  now  proceed  to  lay  before 
you  in  a  tabular  form  the  results  of  a  very  laborious  experi- 
mental attempt  to  distinguish  some  of  the  principal  alkaloids 
and  active  principals,  whether  derived  from  the  vegetable  or 
animal  kingdom,  from  each  other. 
As  the  first  object  which  I  had  in  view  was  to  distinguish  the 
poisonous  alkaloids  and  analogous  active  principles  from  each 
other,  these  substances  are  of  course  admitted  into  the  tables ; 
but  I  have  added  to  these  active  principles  of  many  of  our 
aperient  medicines  and  common  articles  of  diet ;  and  have  ex- 
cluded only  such  of  those  substances  as  were  so  strongly  cha- 
racterized by  color  or  odor,  as  not  to  be  properly  grouped  with 
the  colorless,  or  faintly-colored,  and  inodorous  alkaloids  and 
active  principles. f  The  table,  divided  for  convenience  into  two, 
consists,  as  it  is,  of  as  many  as  thirty -five  different  substances, 
closely  resembling  each  other  in  physical  properties  and  che- 
mical composition,  and  offering  collectively  a  very  difficult  sub- 
ject for  tabular  analysis.  The  tables,  as  you  have  them  before 
you,  are  the  result  of  a  long  series  of  experiments,  and  were 
only  made  to  assume  their  present  form  after  a  great  many  ex- 
perimental groupings  and  transpositions. 
The  first  object  which  I  had  in  view  was  to  find  some  simple 
test  which  would  divide  the  whole  body  of  active  principles 
comprised  in  the  two  tables  into  two  principal  groups.  Con- 
centrated sulphuric  acid,  as  a  constituent  of  the  strychnia  color- 
*  In  the  lectures  given  at  the  College  of  Physicians,  Mr.  Jenkins'  origi- 
nal table,  and  the  two  tabular  arrangements  alluded  to  in  the  text,  were 
sent  round.  These  tables  were  the  more  freely  used  as  illustrations  of  a 
want  of  logical  arrangement,  as  the  author  evidently  did  not  aim  at  diag- 
nosis, but  only  at  the  distinct  ascertainment  of  the  peculiar  and  charac- 
teristic reactions  of  strychnia.  The  remarks  in  the  text  were  not,  there- 
fore, intended  in  any  respect  as  a  censure  of  Mr.  Jenkins  for  not  adopting 
an  arrangement  which,  for  his  purpose,  was  unnecessary.  I  may  add, 
that  his  table  comprises  several  substances  which  will  not  be  found  in  the 
tables  I  am  about  to  submit.  I  mean  such  substances  as  the  kinic  and 
kinovic  acids,  and  such  animal  products  as  urea  and  uric  acid. 
t  To  this  statement  it  will  be  seen  that  there  are  one  or  two  exceptions, 
such  as  naphthaline,  which,  though  colorless,  has  the  odor  of  tar. 
