260  Action  of  Santonin  and  its  Derivatives.  {^"'May'i^.^''"'' 
polarized  light.  Photosantonio  acid,  C15H22O5,  has  a  oarcotic  action  on 
frogs,  doses  of  0*02  to  0"03  gram  abolishing  first  voluntary  movement^ 
then  the  movements  of  respiration ;  the  heart  and  reflexes  are  but 
little  affected  :  doses  of  0*04 — 0'06  gram  first  diminish,  and  then  abol- 
ish reflexes,  and  stop  the  heart  in  diastole.  In  vertebrate  animals  the 
action  is  similar,  except  that  the  reflexes  are  not  affected.  Fhotosan- 
tonin,  C17H24O4,  acts  in  the  same  way,  but  on  account  of  its  smaller 
solubility  the  effects  are  not  so  marked.  Santonin,  C^^Hi^O^,  itself, 
and  sodium  santonate  cause  as  their  chief  symptoms  convulsions ;  it 
seems  then  that  the  action  of  light  is  to  modify  the  physiological  action 
of  these  compounds  on  the  nervous  system  ;  the  action  on  the  respira- 
tory and  circulatory  systems  is,  however,  the  same.  Santonic  acid^ 
C15H20O4,  in  doses  of  0'03  gram,  causes  no  effect  in  frogs  ;  0'04  to  0'05 
gram  produces  narcosis,  abolishes  respiratory  movements,  but  does  not 
lessen  reflexes.  Larger  doses  affect  the  reflexes  and  kill  the  animal ; 
if  the  dose  is  not  lethal,  the  animal  experiences  clonic  convulsions  like 
those  produced  by  santonin,  as  the  narcosis  passes  off.  In  a  rabbit  of 
1  kilo,  body- weight,  doses  of  1  to  1*5  gram  applied  hypodermically 
have  no  effect :  2  to  3  grams  caused  sleep  in  J  to  1  hour,  and,  like 
santonin,  epileptic  convulsions.  There  is  no  action  on  the  circulation,. 
except  with  lethal  doses,  which  stop  the  heart  in  diastole :  atropine 
does  not  antagonize  this  action;  this  acid  thus  produces  the  effect  of 
santonin  combined  with  that  of  the  photo-compounds,  both  narcosis 
and  convulsions.  Santonic  and  isosantonic  acids  act  like  photosantonic 
acid.  Isophotosantonin,  C17H24O4,  is  no  hypnotic,  but  easily  causes 
strong  convulsions.  Isophotosantonic  acid,  Ci5H22[4]05,  acts  similarly ,^ 
but  is  weaker.  The  derivatives  of  santonin  that  cause  convulsions  do 
so  by  their  action  on  the  medulla,  not  on  the  spinal  cord.  The  photo- 
derivatives  contain,  like  santonin,  a  closed  naphthalene  nucleus,  and 
the  differences  in  their  constitution  are  to  be  found  in  the  side-chains. 
There  was  found  to  be  no  connection  between  physiological  action  and 
the  direction  or  amount  of  rotation  of  the  plane  of  polarized  light. 
JVutrient  Enemata — Physicians  will  generally  indorse  the  conclusions 
of  Professor  Ewald,  of  Berlin,  who  has  recently  made  some  experiments  with 
different  nutrient  enemata,  and  has  found  that  enemata  of  eggs  were  of  de- 
cided service,  and  that  they  were  as  efficient  and  satisfactory  without  being 
peptonized  as  when  they  were  subjected  to  this  process. — Louisv.  Med.  Her- 
ald, April,  1888. 
