172 
ON  THE  OLEANDER. 
came  over,  held  in  solution  by  other  principles,  and  that  the 
alkaline  and  earthy  chlorides  favored  this  division. 
On  subjecting  the  bark  to  the  action  of  water,  alcohol,  and 
ether,  M.  Latour  found  that  the  acrid  yellow  resin  that  it  con- 
tained was  identical  with  that  of  the  leaves,  and  that  it  resided 
chiefly  in  the  white  cortical  part  (liber;)  the  flowers  likewise 
contain  this  yellow  resinous  matter ;  they  also  contain  a  yellow, 
odorous,  adhesive,  fatty  matter,  of  a  soft  consistence,  which 
appears  to  be  a  mixture  of  fatty  oil  and  caoutchouc  ;  a  thick 
fatty  paste,  soluble  in  alcohol  and  ether,  saponifiable  by  alkalies  ; 
a  red  coloring  matter,  insoluble  in  ether,  soluble  in  alcohol  and 
water,  possessing  the  characters  of  tannin  ;  finally,  tannin  com- 
bined with  a  very  acid  yellow  coloring  matter,  gallic  acid, 
uncrystallisable  sugar,  albumen  and  pectine. 
One  observation  made  by  M.  Latour  deserves  special  mention ; 
he  has  found  that  the  proportion  of  the  poisonous  acrid  resin  is 
more  abundant  in  the  oleander  when  growing  wild  than  when 
cultivated. 
After  making  a  most  profound  study  of  the  coloring  matter  of 
the  flowers  and  ascertaining  its  presence  in  the  bark,  M.  Latour 
thus  sums  up  his  interesting  researches  on  this  plant. 
1st.  The  poisonous  principle  of  the  oleander  exists  in  the  leaf, 
the  bark,  and  the  flowers,  but  in  unequal  proportions ;  the  bark 
contains  the  largest  quantity,  the  leaf  and  the  flowers  about  equal 
proportions. 
2nd.  The  poisonous  principle  is  of  a  resinous  nature,  not  vola- 
tile, showing  itself  under  two  modifications.  With  regard  to  its 
solubility  in  ether,  this  modification  is  more  apparent  than  real, 
and  may  be  the  result  of  the  presence  of  a  foreign  principle. 
3rd.  The  solubility  of  this  resin  is  singularly  facilitated  by 
the  alkaline  salts  ;  for  this  reason  the  aqueous  extracts  of  the 
leaves  and  flowers,  which  contain  a  larger  proportion  of  these 
salts,  are  more  active  than  the  aqueous  extract  of  the  bark  ;  but 
the  inverse  is  the  case  with  the  alcoholic  extracts  ;  that  of  the 
bark  shows  nearly  double  the  activity  of  that  of  the  correspond- 
ing extracts  of  the  flower  and  leaf. 
4th.  The  distilled  waters  obtained  with  the  bark  and  the  leaf, 
possess  an  activity  which,  when  carefully  studied,  might  become 
useful  in  therapeutics  ;  it  is  entirely  due  to  the  resin  carried  over 
