24 
Goto  Barks, 
Am.  Jour  Pharm. 
Jan.,  1880 
ammonia,  and  crystallizes  from  the  hot  solutions.  It  has  a  neutral  reac- 
tion, is  tasteless,  and  is  not  colored  by  ferric  chloride.  Its  composition 
is  Cj9Hj20g,  and  on  being  dissolved  in  solution  of  potassa  or  soda,  it  is 
converted  into  a  weak  acid — paracotoic  acid,  C^gH^^Oy.  Sulphuric  and 
nitric  acid  dissolve  paracotoin  yellowish  brown,  the  warm  solution  of 
the  latter  depositing  on  cooling  yellow  prisms. 
On  adding  bromine  to  the  chloroformic  solution  of  paracotoin 
hydrobromic  acid  is  given  off,  and  a  scarlet-red  crystalline  precpitate  is 
produced,  which,  on  dryiiig,  becomes  yellow  and  at  I00°C.  green,  with 
the  evolution  of  hydrobromic  acid  ;  its  composition  is  CggHgiBrgO^a^ 
On  fusing  paracotoin  with  caustic  potassa,  protocatechuic  and  formic 
acids  are  produced  ;  and  on  boiling  it  with  solution  of  potassa  para- 
cumarhydrin^Q^W^O^  is  formed,  which  is  in  colorless  scales  of  a  couma- 
rin-like  odor;  neutral  to  test  paper,  and  freely  soluble  in  ether,  alcohol, 
aceton  and  chloroform,  but  sparingly  soluble  in.  cold  water.  At  the 
same  time  an  acid  homologous  with  piperonylic  acid  is  generated,  and 
paracotoic  acid^  C^gH^^O^,  which  is  insoluble  in  water,  readily  soluble  in 
alcohol  and  ether,  and  not  colored  by  ferric  chloride. 
Leucotin,  C3^H320jq,  is  present  in  largest  proportion  among  the 
crystalline  constituents  of  paracoto  bark,  and  is  readily  dissolved  from 
the  mixture  by  glacial  acetic  acid,  and  purified  by  recrystallization  from 
warm  dilute  alcohol.  It  crystallizes  in  small  white  prisms,  which  are 
readily  soluble  in  alcohol,  ether,  chloroform,  aceton  and  glacial  acetic 
acid.  It  melts  at  97°C.,  is  not  colored  by  ferric  chloride,  and  yields 
with  strong  nitric  acid  a  blue-green  resin  and  a  blue-green  solution, 
which  is  rendered  turbid  by  water.  It  yields  with  bromine  d'lhromleu- 
cotin^  Cg^HggBrgOjQ,  and  tetrahromleucot'in ^Q^^^^x fly^^  which  are  crys- 
talline. 
On  fusing  leucotin  with  potassa,  hydrocoton,  CjgHg^Og  is  volatilized, 
and  protocatechuic  and  formic  acid  are  formed,  together  with  protoca- 
techuic aldehyd,  C.HgOg,  and  cotogen'in  C^^H^^Og,  which  is  sparingly 
soluble  in  alcohol  and  ether,  melts  at  2io°C.,  and  at  a  higher  temperature 
vields  pyrocatechin. 
OxYLEUCOTiN,  C3^H320i2,  IS  left  in  the  alcoholic  mother-liquor  of 
paracotoin.  To  free  it  from  the  latter  warm  potassa  solution  is  used, 
and  the  undissolved  oxyleucotin  is  crystallized  from  boiling  alcohol  or 
glacial  acetic  acid,  on  the  cooling  of  which  solvents  it  separates  in 
handsome  prisms,  which  are  also  soluble  in  warm  chloroform,  ether 
