^"'■juiy!i888^°''}         ^^^^d  Hydrocarbons  in  Plants.  323 
The  method  finally  adopted  to  purify,  upon  freeing  the  petroleum- 
ether  residue  from  fats  and  coloring  matter,  was  to  treat  the  residue 
with  boiling  absolute  alcohol,  filter  out  the  wax,  which  separated  on  cool- 
ing, and  allow  the  filtrate  to  evaporate  at  the  ordinary  temperature. 
By  fractional  crystallization  at  least  three  substances  of  different  and 
definite  crystalline  forms  have  been  separated.  We  have,  at  present, 
examined  only  one  of  these  constituent  compounds;  whether  the  others 
are  the  result  of  oxidation  during  the  separating  and  purifying  pro- 
cesses or  exist  as  such  in  the  plants,  we  are  now  unable  to  state. 
The  subject  of  our  communication  is  the  compound  the  least  soluble 
in  alcohol  of  the  three  obtained  by  fractionation.  It  formed  silky, 
acicular  crystals,  often  two  to  four  centimetres  in  length,  which,  under 
polarized  light,  gave  a  play  of  colors.  It  also  exhibited  decidedly 
electrical  properties.  To  determine  the  melting  point,  about  0*5  of  a 
gram  of  the  crystals  were  placed  directly  in  the  inner  tube  of  an  appa- 
ratus devised  by  Roth,  for  the  determination  of  melting  points.  The 
substance  melted  at  196*2°  C.  to  196'4°C.,  leaving  a  clear,  amber- 
colored  mass.  On  heating  to  a  higher  temperature,  the  substance  de- 
composed and  vapor  was  driven  off  in  dense  clouds.  It  had  an  odor 
very  like  sandal  wood ;  when  condensed  upon  a  cool  surface,  the  sub- 
limate consisted  of  fluffy  crystals  of  a  lower  melting  point. 
The  silky,  acicular  crystals  were  soluble  in  petroleum-ether,  ethylic 
and  acetic  ethers,  benzole,  chloroform,  hot  alcohol,  glacial  acetic  acid, 
acetic  anhydride  and  linseed  oil.  The  addition  of  water  to  the  acetic 
anhydride  reprecipitated  the  substance,  in  white,  flakey  masses.  The 
crystals  were  insoluble  in  hot,  cold  or  acidulated  water,  or  in  the  alka- 
lies or  other  hydrate  solutions ;  insoluble  in  amyl  alcohol  and  alco- 
holic soda.  Nitric  and  sulphuric  acids  dissolved  the  crystals;  sul- 
phuric acid  gave  a  reddish-brown  coloration. 
The  first  ultimate  analyses  of  this  purified  product  from  Cascara 
■amarga  gave  the  following  results  : 
I.  II.  III. 
C.   86-30  86-29  86-33 
H.    12-96  12-96  12-83 
99-26  99-25  99*16 
While  the  mean  per  centage  obtained  from  these  combustions  indi- 
cated oxidation  or  the  presence  of  adherent  impurities,  they  also  pointed 
strongly  to  the  conclusion  that  the  compound  was  a  solid  hydrocarbon. 
