ON  THE  BYTTERIA  FEBRIFUGrA. 
338 
Pharmacien  to  the  Fleet,  to  isolate  this  proximate  principle. 
M.  Gerardias  has  obtained  the  bitter  principle  of  the  bitter 
ash,  by  exhausting  the  wood  by  decoction  in  water,  treating  the 
concentrated  decoction  with  sub-acetate  of  lead,  and  evaporating 
the  filtered  liquid  after  having  separated  the  excess  of  lead  with 
sulphuric  acid. 
The  substance  which  separated  towards  the  close  of  the  evap- 
oration, under  the  form  of  crystalline  pellicles,  was  dissolved  in 
alcohol,  decolored  by  animal  charcoal,  and  obtained  perfectly 
white  and  crystallised. 
The  average  yield  was  three  grammes  per  kilogramme  of 
wood. 
Thus  obtained  in  a  state  of  purity,  this  substance  presents  the 
following  characters ;  it  is  white,  crystalline,  inodorous,  and  ex- 
cessively bitter. 
When  slightly  heated  it  melts  into  a  colorless  liquid,  and  on 
cooling  becomes  a  transparent  non-crystalline  mass.  If  the  heat 
is  continued,  the  liquid  at  last  disappears,  after  diffusing  white 
vapors.  When  the  heat  is  greater  and  suddenly  applied  it  gives 
a  brown  liquid,  diffusing  yellow  vapors  which  are  not  ammonia- 
cal,  which  condense  in  small  empyreumatic  and  slightly  acid 
drops,  and  it  leaves  a  very  abundant  carbonaceous  residue. 
It  is  nearly  insoluble  in  cold  water ;  nevertheless,  this  liquid 
retains  sufficient  to  become  extremely  bitter ;  it  dissolves  much 
better  with  the  aid  of  heat. 
Concentrated  sulphuric,  nitric  and  hydrochloric  acids  dissolve 
it  cold  and  without  coloration ;  but  the  addition  of  water  precip- 
itates it  immediately. 
It  dissolves  readily  without  heat  in  alcohol,  and  this  solution, 
which  is  neutral  to  litmus,  is  not  precipitated  by  water.  This 
alcoholic  solution,  diluted  with  water,  is  not  precipitated  with 
sub-acetate  of  lead,  but  is  precipitated  white  by  tannin  and  brown 
by  ioduretted  iodide  of  potassium. 
As  until  then  no  one  knew  to  what  family  the  bitter  ash  be. 
longed.  MM.  Chapuis,  surgeon  of  the  first  class  to  the  fleet,  and 
Belanger,  director  of  the  Jardin  des  Plantes  of  Saint  Pierre, 
were,  at  the  desire  of  M.  Amic,  sent  to  Saint  Martin  by  the 
Government  of  Martinique,  to  study  this  plant.  These  gentle- 
men determined  that  the  bitter  ash  was  a  plant  not  hitherto  de- 
