^  Augu"  t  issT' }  Ptomaines.  407 
in  separating  the  true  alkaloids  from  the  ptomaines,  with  which  one 
must  expect  to  see  them  associated  when,  in  a  case  of  poisoning,  the 
chemical  analysis  is  not  proceeded  with  immediately,  that  is  to  say, 
from  24  to  48  hours  after  death.  Notwithstanding  the  employment 
of  the  successive  solvents  indicated  in  the  method  of  Dragendorff,  and 
the  ultimate  transformation  of  the  extracts  into  crystal lizable  salts,  the 
alkaloids  are  always  obtained  more  or  less  mixed  with  ptomaines,  and 
consequently  afford  the  reaction  of  Prussian  blue.  And  as  to  this 
character  there  may  be  added  others  which  are  common  to  certain 
ptomaines  and  to  certain  vegetable  alkaloids,  one  can  conceive  the 
embarassment  in  which  the  chemist  finds  himself  precipitated  if  he 
docs  not  take  the  pains  to  determine,  without  a  single  exception,  all 
the  properties  of  the  isolated  body,  and  to  compare  the  results  obtained 
with  the  reactions  indicated  for  the  substance  which  he  believes  to 
liave  in  hand.  It  is  only  under  the  conditions  of  most  scrupulous 
work,  pushed  to  the  extreme,  that  one  is  able  to  avoid  confusion ;  and 
to  demonstrate  how  great  the  causes  of  error  may  be,  the  following 
vcase,  as  signalized  by  Brouardel  and  Boutmy  may  be  cited. 
These  distinguished  chemists  have  abstracted  from  the  cadaver  of  a 
drowned  person,  which  had  reposed  18  months  under  water,  a  fixed 
alkaloid  of  animal  origin,  presenting  all  the  chemical  and  physiological 
reactions  of  veratrine,  and,  largely  diluted,  that  of  Prussian  blue. 
Admitting  that  there  had  been  intoxication  by  veratrine,  how  was  it 
possible  to  arrive  at  a  distinction  between  the  veratrine  and  the  animal 
alkaloid  with  which  it  may  have  been  mixed,  otherwise  than  by  the 
crystallization  of  the  base  and  the  exact  determination  of  its  crystalline 
form.  One  could  have  likewise  ascertained  if,  after  the  hypodermic 
injection  of  the  isolated  poison,  the  muscular  excitement  by  the  induc- 
tion current  persisted;  but  if  the  proportion  of  the  ptomaine  had  been 
larger  than  that  of  the  veratrine,  this  character  would  be  found  to  be 
forcibly  masked  in  consequence  of  this  relative  excess. 
It  appears  equally  difficult  to  distinguish  morphine  from  a  ptomaine; 
both  of  them  reduce  the  ferricyanide  of  potassium,  and  produce  physi- 
ological symptoms  among  which  those  of  poisoning  by  the  acrid  nar- 
cotics predominate ;  but  happily  Frohde's  reagent  and  ferric  chloride 
will  permit  of  recognizing  morphine,  and  the  physiological  experiment 
will  show  that  morphine  only  produces  death  slowly,  with  a  large 
dose,  in  stupefying  the  animal,  and  leaves  the  muscles  sensitive  to 
electric  excitement;  but  here  still  the  preceding  objection  may  be 
