70  EXPERIMENTAL  RESEARCHES  ON  OPIUM  AND  ITS  ALKALOIDS. 
to  the  extent  that  I  had  proposed  and  wished,  but  should  I  be 
again  permitted  to  furnish  a  paper  to  the  Conference,  I  hope  to 
devote  more  attention,  and  to  direct  my  observations  more  use- 
fully. — London  Pharm.  Jour,,  Nov.,  1864. 
EXPERIMENTAL  EESEARCHES  ON  OPIUM  AND  ITS 
ALKALOIDS. 
By  M.  Claude  Bernard. 
This  eminent  physiologist  was  led  to  experiment  on  the  effects 
of  all  the  alkaloids  of  opium  from  noticing  great  and  unexpected 
variations  in  those  effects  when  the  alkaloids  were  employed  to 
facilitate  experiments  on  living  animals.  He  found,  in  fact, 
that  the  six  principal  alkaloids — morphia,  narceia,  codeia, 
narcotina,  papaverina  and  thebaina — each  produced  a  particular 
effect,  but  the  action  may  be  classed  under  three  heads — the  so- 
porific, the  exciting  or  convulsive,  and  the  poisonous  action. 
The  relative  power  of  the  alkaloids  to  produce  these  effects  is 
indicated  by  their  position  in  the  following  table : — 
Soporifics.  Excitants.  Poisons. 
Narceia  Thebaina  Thebaina 
Morphia  Papaverina  Codeia 
Codeia  Narcotina  Papaverina 
Codeia  Narceia 
Morphia  Morphia 
Narceia  Narcotina 
Thus  it  is  seen  that  three  only  produce  purely  soporific  effects, 
but  even  these  vary  greatly  in  character  and  degree.  Mor-  « 
phia,  for  example,  produces  a  stupifying  effect.  The  animal  is 
scarcely  insensible,  but  becomes  a  sort  of  living  machine,  and  will 
remain  in  any  position  in  which  it  is  placed.  The  sensitive  nerves 
are  extremely  dull,  and  the  extremities  may  be  strongly  pinched 
without  disturbing  the  animal.  When  roused  by  a  noise  it 
seems  frightened,  but  quickly  relapses  into  narcotism.  As  the 
animal  awakens  it  has  a  haggard  look,  and  the  hinder  extremi- 
ties seem  partially  paralysed,  so  that  it  walks  like  a  hyaena. 
The  effects  of  codeia  are  essentially  different.  The  animal 
is  tranquil,  and  seems  to  be  in  calm  sleep,  but  he  is  at  the  same 
time  very  excitable ;  a  slight  noise  wakes  him  up,  and  he  runs 
