INFLUENCE  OF  MORPHIA  IN  DISGUISING  STRYCHNIA. 
215 
H  Expt.  3.  This  was  an  exact  repetition  of  Expt.  2,  except  that  to  the 
l-100th  of  a  grain  of  strychnia,  three  times  that  quantity  of  morphia  (l-33d 
of  a  grain)  was  added.  On  treating  this  by  Staas'  process,  as  in  the  pre- 
ceding cases,  I  could  not  discover  the  slightest  trace  of  either  strychnia  or 
morphia,  even  after  the  ultimate  ethereal  solution  was  concentrated  to  a 
very  small  bulk  by  evaporation." 
As  the  first  two  experiments  were  precise  counterparts  of 
those  employed  in  the  analysis  of  the  stomach,  the  author  feels 
justified  in  believing  them  to  be  delicate  and  reliable,  and  that 
the  poison  should  have  been  isolated  if  present,  unless  its  pres- 
ence was  masked.  The  third,  he  thinks,  seems  to  prove  mo3t 
unequivocally  that  morphia,  when  present  in  excess  along  with 
strychnia,  has  this  property  of  concealing  the  latter  from  the 
usual  color-test. 
"  Expt.  4.  This  was  also  a  repetition  of  Expt.  2,  except  that  to  the  l-100th 
grain  of  strychnia,  the  l-50th  grain  of  morphia  was  added  instead  of  the  l-33d 
— or  double  instead  of  treble  the  quantity.  Here,  likewise,  there  was  a 
total  failure  to  discover  the  poison. 
"  Expt.  5.  This  was  a  repetition  of  the  last,  except  that  only  l-100th 
grain  of  morphia  was  added  to  the  l-100th  grain  of  strychnia,  or  an  equal 
portion.  The  result  here  was  that  I  obtained  the  faintest  possible  evi- 
dence of  the  presence  of  strychnia,  and  only  after  repeated  trials. 
From  these  last  experiments  I  think  we  may  conclude  that  the  influence 
of  Morphia  in  preventing  the  detection  of  minute  quantities  of  strychnia,  in 
the  presence  of  an  organic  fluid,  depends  upon  the  relative  quantity  of  the  two 
alkaloids  ; — the  strychnia  being  not  discoverable  when  the  morphia  is  in  excess, 
and  barely  discoverable  when  in  equal  quantity. 
Dr.  Reese  next  instituted  a  set  of  experiments  with  a  view  of 
ascertaining  the  eifect  of  morphia  in  disguising  the  presence  of 
strychnia  in  perfectly  pur e  solutions,  free  from  organic  mixtures, 
and  the  result  pointed  to  the  fact  that  the  minuteness  of  the 
proportions  detectible  by  the  color-test  was  inversely  as  the  pro- 
portion of  morphia  was  increased,  as  will  be  shown  in  the  fol- 
lowing tabular  view: 
When  the  proportion  of  the  two  alkaloids  was 
One  strychnia  to  one  morphia  he  was  able  to  detect     l-500,000th  of  a  gr. 
One      "        to  two       "       "       "       "         1-300,000    "  " 
One      «        to  three     "       "       "       "         1-150,000   "  " 
One      "        to  four      "       "       "       «         1-100,000   "  " 
One      «        to  five       «       "       "       "  1-80,000    "  " 
One      "        to  ten        "       "       "       "  1-10,000    "  " 
One     "        to  twenty  "       "       "       "  1-5000   "  " 
