258 
NOTE  ON  THE  DETECTION  OF  STRYCHNIA. 
the  third  hours,  other  similar  additions  were  made,  no  symptoms 
of  strychnism  having  appeared.  At  the  end  of  the  fifth  hour, 
the  frog  having  been  exposed  to  the  action  of  one-fiftieth  part 
of  a  grain  of  the  acetate  of  strychnia,  tetanus  came  on,  and  un- 
der the  same  circumstances  of  removal  and  washing,  as  in  the 
former  experiment,  proved  fatal  in  its  turn. 
I  thus  detected  one-fiftieth  part  of  a  grain  of  tie  poisonous 
salt  by  phenomena  too  vivid  to  admit  of  a  moment's  doubt,  the 
animal,  on  the  slightest  touch,  became  seized  with  the  most  gene- 
ral spasmodic,  or,  rather,  tetanoid  rigidity.  And  this  phenome- 
non, alternating  with  perfect  relaxation,  was  repeated  again  and 
again. 
As  the  nerve  and  muscles  of  the  frog's  leg,  properly  prepared, 
have  been  very  aptly  designated  as  galvanoscopic,  so  the  whole 
frog,  properly  employed,  becomes  strychnoscopic. 
In  cases  of  suspected  poison  from  strychnia,  the  contents  of 
the  stomach  and  intestines,  and  the  contents  of  the  heart,  blood- 
vessels, &'c,  must  be  severally  and  carefully  evaporated,  and 
made  to  act  on  lively  frogs,  just  taken  from  the  ponds  or  mud. 
I  need  scarcely  say,  that  taken  in  winter  the  frog  will  prove 
more  strychnoscopic  than  in  summer,  in  the  early  morning  than 
in  the  evening. 
The  best  mode  of  performing  the  experiment  also  remains  to 
be  discovered,  with  all  its  details  and  precautions — an  inquiry 
into  which  I  propose  to  enter  shortly.  Meantime  this  note 
may  not  be  without  its  utility. 
Princes  Street,  Hanover  Square,  January,  1856. 
Postscript. — -I  have  repeated  my  experiment.  I  placed  one 
frog,  fresh  from  the  pools,  in  an  ounce  of  water,  containing  the 
one-fiftieth  part  of  a  grain  of  the  acetate  of  strychnia  ;  a  sec- 
ond in  the  same  quantity  of  water,  containing  the  one-sixty- 
sixth,  a  third  containing  one-one-hundredth,  and  a  fourth  con- 
taining one  two-hundredth.  All  became  tetanic  in  two  or  three 
hours,  except  the  third,  which  was  a  female  (the  others  being 
males),  which  required  a  longer  time. 
The  one  two-hundredth  part  of  a  grain  of  the  acetate  of 
strychnia  is  therefore  detectible  by  means  of  the  test  conferred 
by  physiology. 
