ON  MANGOSTINE. 
333 
produced  was  gelatinous,  yellow,  insoluble  in  water,  slightly  so- 
luble in  alcohol,  and  decomposable  by  acids.  When  dried  at 
212°  F.,  it  could  be  pounded  into  a  light  yellowish-green  powder, 
which  when  heated  burnt  away  quietly  without  scintillation. 
Analysis  led  to  the  formula  2(C40  H22  O10)-f  5PbO  +  HO : — 
Found.  Calculated. 
Carbon,  38-67       80        6000  38.37 
Hydrogen,  345       45         562-5  3-59 
Oxygen,  13-74       21        2100  1346 
Oxide  of  lead,*'         44-14         5        6972-5  44-58 
This  lead  compound  is  not  always  of  the  same  composition,  for 
in  two  analyses  of  a  compound  prepared  at  another  time  the 
author  obtained  37-85  and  3746  per  cent,  of  oxide  of  lead. 
Several  other  bodies,  obtained  from  plants  of  the  same  natural 
family  (G-uttiferse}  as  the  Grarcinia  mangostana,  appear  to 
possess  a  certain  relation  with  mangostine,  both  in  regard  to 
to  their  formulae  and  chemical  properties. 
According  to  Johnston,  gamboge  obtained  from  Grarcinia  gutta 
has  the  formula  C40  H18  O21.  From  this  it  appeared  probable 
that  mangostine  might  be  obtained  by  the  oxidation  of  gamboge. 
The  author  accordingly  treated  the  latter  substance  with  hot  con- 
centrated nitric  acid,  and  obtained  a  crystalline  body  which  ap- 
peared to  possess  reactions  exactly  analogous  to  those  of  man- 
gostine. 
Indian  yellow  (purree),  which  is  said  to  be  obtained  from  the 
deposite  of  camel's  urine  after  the  animals  have  eaten  the  fruit 
of  Mangostana  magnifer,  consists  principally  of  euxanthate  of 
magnesia;  the  acid  of  this  salt  has  the  formula  C40H16O21. 
Hence  it  appears  possible  that  both  mangostine  and  gamboge 
may  be  converted  into  euxanthic  acid  by  passing  through  living 
bodies. 
From  this  the  author  was  induced  to  make  some  experiments 
with  euxanthic  acid,  from  which  it  appeared  that  this  acid  is  a 
conjugate  compound.  Thus  if  it  be  treated  with  concentrated 
nitric  acid,  and  the  fluid  be  poured  into  water,  euxanthone  sepa- 
rates. The  fluid  filtered  from  this  substance  has  the  property  of 
reducing  peroxide  of  copper  dissolved  in  potash,  a  power  possessed 
neither  by  euxanthic  acid  nor  by  euxanthone. — London  Ohem 
Qaz.  from  Liebig's  Annalen,  xciii.  p.  83. 
