ON  THE  COMPOSITION  OF  CREOSOTE. 
227 
certainty.  The  investigation  of  a  series  of  chlorinated  products 
allowed  the  formula  C':6  H16  Ol  to  be  deduced  for  creosote  with  a 
certain  amount  of  probability. 
During  the  time  in  which  the  author  had  been  occupied  with 
this  investigation,  Volckel  also  published  his  investigation  of 
creosote.  According  to  Volckel,  creosote  prepared  by  Reichen- 
bach's  method  is  not  pure,  but  contaminated  by  a  small  residue 
of  volatile  oils,  which  acquire  color  when  exposed  to  the  light. 
Volckel  purified  his  creosote  by  solution  in  potash  and  distilla- 
tion, and  thus  obtained  a  creosote,  the  analysis  of  which  led  to 
the  formula  C'24  Hu  O5 ;  a  basic  lead  compound  had  the  composi- 
tion C24  II13  0\  PbO-f  2PbO. 
The  creosote  analyzed  by  Volckel  dissolved  in  ordinary  acetic 
acid  and  in  dilute  solution  of  potash,  properties  which  Volckel 
regarded  as  a  criterion  of  the  purity  of  creosote.  This  creosote, 
therefore,  differs  from  the  author's  in  many  points. 
Volckel's  creosote  contained  less  carbon  and  hydrogen  than 
the  author's;  it  had  a  higher  specific  gravity  (1-076  Volckel, 
1-040  Von  Gorup-Besanez,)  and  was  perfectly  soluble  in  dilute 
solution  of  potash  and  in  ordinary  acetic  acid,  whilst  the  author's 
was  only  partially  soluble  in  these  menstrua ;  when  Volckel's 
creosote  was  heated  with  lime  no  color  was  produced,  whilst  the 
author's  became  blackish  under  this  treatment.  Both,  however, 
were  obtained  from  wood  tar,  the  author's  from  beech  tar,  but 
the  wood  from  which  Volckel's  was  obtained  is  not  stated ;  they 
had  the  same  boiling  point,  and  when  boiled  exhibited  the  same 
phenomena  ;  on  distillation  with  calcined  lime,  they  furnished 
oils  of  nearly  the  same  composition. 
Volckel  regarded  the  creosote  treated  by  the  author  as  not 
perfectly  pure,  because  it  was  not  treated  with  solution  of  potash. 
The  author  has  therefore  repeated  his  experiments.  He  treated 
one  pound  of  creosote  with  solution  of  potash,  according  to 
Volckel's  directions,  and  separated  therefrom  three  to  four  ounces 
of  a  product  boiling  between  395°  and  410°  F.,  as  pure  creosote. 
This  had  the  following  properties  : 
It  was  a  perfectly  colorless,  strongly  refractive  fluid,  of  an 
unpleasant  odor,  but  decidedly  purer  than  that  presented  by  the 
commercial  creosote,  and  somewhat  similar  to  that  of  guaiacole. 
Spec.  grav.  at  55°-4  F.— 1-057.    With  persalts  of  iron,  salts 
