332 
ON  MANGOSTINE. 
yellow,  silky  laminse  ;  so  that  by  pouring  the  fluid  from  the  de- 
posit of  resin,  the  mangostine  may  be  obtained  tolerably  pure. 
To  purify  it  farther,  it  is  dissolved  in  alcohol,  and  precipitated 
with  basic  acetate  of  lead.  The  precipitate  is  well  washed,  sus- 
pended in  alcohol,  and  decomposed  whilst  hot  by  sulphuretted 
hydrogen.  The  filtered  solution  is  then  mixed  with  water  whilst 
boiling  until  it  becomes  milky,  as  the  mangostine  only  crystal- 
lizes from  a  dilute  alcoholic  solution.  The  complete  purification 
of  the  substance  is  completed  by  repeated  crystallization  from 
alcohol. 
Mangostine  crystallizes  in  thin  laminae,  of  a  fine  golden  lustre  ; 
it  is  tasteless  and  inodorous  ;  melts  at  about  374°  F.  without  loss 
of  water,  forming  a  thick,  transparent,  deep  yellow  fluid,  which 
solidifies  on  cooling  into  a  brittle,  amorphous,  transparent  mass  ; 
it  is  heavier  than  water.  When  heated  above  its  melting-point, 
it  is  for  the  most  part  decomposed,  but  a  part  sublimes  unchanged. 
It  burns  on  platinum  foil  without  residue.  It  is  soluble  in  water, 
but  dissolves  readily  in  alcohol  and  ether.  The  solutions  have  no 
reaction  on  litmus-paper. 
Dilute  acids  dissolve  the  greater  part  of  it  with  the  aid  of  a 
moderate  heat,  and  deposit  it  again  unchanged  on  cooling.  Con- 
centrated  nitric  acid  converts  it  into  oxalic  acid  at  an  elevated 
temperature.  Cold  concentrated  sulphuric  acid  dissolves  it  with 
partial  decomposition,  and  with  a  dark  yellowish-red  color  ;  when 
heated,  carbonization  commences.  It  dissolves  in  alkalies  with 
a  yellow  or  brownish  color.  It  is  not  precipitated  by  metallic 
salts,  with  the  exception  of  basic  acetate  of  lead.  It  reduces  the 
oxides  of  the  noble  metals.  With  chloride  of  iron  it  produces  a 
greenish-black  color,  which  disappears  on  the  addition  of  acids. 
Analysis  led  to  the  formula  C40  H22  O10:— 
I.  II.  III. 
Carbon  69-64    69.63    69-74    40    3000  70-17 
Hydrogen  6-66  6-37  6.44  22  275  6-43 
Oxygen  23-70    24-00    23-82    10    1000  23-40 
For  the  preparation  of  the  compound  of  mangostine  and  oxide 
of  lead,  the  substance  was  dissolved  in  alcohol,  and  then  treated 
with  an  alcoholic  solution  of  neutral  acetate  of  lead,  in  such  a 
manner  that  all  the  mangostine  was  not  precipitated  by  the 
addition  of  a  small  quantity  of  ammonia.     The  precipitate  thus 
