4io 
Wood-  Tar  Creosote. 
f  Am.  Jour.  Pharm. 
I  September,  18f 9. 
guaiacol  and  creosol,  the  former  predominating  in  one  case  and  the 
latter  in  another.  This  idea  has  become  so  prevalent  among  some, 
that  they  thought  guaiacol  to  the  extent  of  sixty  or  more  per  cent, 
could  easily  be  obtained  by  fractionating  a  good  quality  of  creosote. 
Such  may  have  been  the  quality  of  creosote  years  ago,  but  things 
have  changed.  It  is  claimed  that  when  a  demand  arose  for  guaiacol 
and  its  salts,  the  proportion  of  this  valuable  compound  began  gradu- 
ally to  diminish,  until  to-day  it  has  become  difficult  to  purchase 
creosote  containing  20  per  cent.,  and  an  article  containing  60  per 
cent,  is  a  curiosity.  The  above  demand  may  have  had  an  influence, 
but  the  writer  is  inclined  to  look  at  it  somewhat  differently.  The 
high  percentage  of  guaiacol  reported  by  some  workers  was  probably 
due  to  faulty  methods  of  analysis. 
A.  Behal1  and  E.  Choay,  on  fractionating  genuine  beechwood 
creosote  and  analyzing  those  portions  coming  over  between  2000  and 
2100  C,  and  200°  and  220°  C,  found  them  to  have  the  following 
composition  : 
Boiling-Points, 
Boiling-Poinl 
200-210°  C. 
200-220°  C. 
Per  Cent. 
Per  Cent. 
39-00 
26-48 
IC72 
  32-14 
39"98 
  2'38 
1-30 
The  above  analyses  indicate  that  a  specimen  of  creosote  contain- 
ing 25  per  cent,  of  guaiacol  is  a  fairly  good  one.  Other  recent 
analyses  contribute  towards  this  view.  But  it  must  be  remembered 
that,  while  the  larger  proportion  of  the  guaiacol  distils  between  the 
above  temperatures,  not  all  comes  over.  This  is  well  shown  by  the 
results  of  the  present  investigation.  Those  samples  beginning  to 
boil  at  about  2100  G.  (corrected)  contain  the  largest  amount  of 
guaiacol.  The  probable  reason  for  finding  the  guaiacol  in  higher 
fractions  is  that  we  find  it  almost  impossible  to  closely  separate  by 
fractionation  the  various  components  of  complex  mixtures,  like 
creosote.  It  has  been  found  that  a  fraction  of  creosote  coming  over 
between  200°  and  2100  C.  may  contain  a  goodly  per  cent,  of  phenol 
having  a  boiling-point  200  below  the  lowest  boiling-point.  And 
the  same  fraction  has  been  found  to  contain  more  than  one-third  its 
weight  of  creosol,  a  body  having  a  boiling-point  of  2190  C. 
1  1894,  Comb,  rend.,  ug,  166. 
