538 
ON  TRUE  AND  FALSE  CREOSOTE 
coloring  matters,  which  form  the  greater  part  of  the  quinoidine  of 
commerce.  I  have  ascertained,  in  fact,  that  when  a  salt  of  quinine 
or  cinchonine  in  a  dilute  or  concentrated  solution  is  exposed  to 
the  sun  even  for  a  few  hours,  it  becomes  changed  to  such  an  extent 
that  the  liquid  acquires  an  extremely  dark  reddish-brown  color. 
This  change,  moreover,  is  of  the  same  nature  as  that  which  is 
effected  by  the  influence  of  an  elevated  temperature.  I  believe, 
therefore,  that  considerable  loss  of  quinine,  cinchonine,  &c.  would 
be  avoided,  and  that  the  extraction  of  these  bases  would  be 
rendered  more  easy,  if  the  bark  was  shaded  from  the  light  when 
collected,  and  dried  in  the  shade.  The  manufacturer  of  quinine 
ought  also  to  avoid  the  action  of  a  bright  light. — Comptes  Rendu*, 
from  Chem.  Gazette,  Sept.  1,  1853. 
ON  TRUE  AND  FALSE  CREOSOTE. 
BY  GORUP-BESANEZ. 
Creosote  has  been  seldom  the  object  of  scientific  investigation 
since  its  discovery.  The  consequence  is,  that  our  knowledge  of 
this  interesting  body  remains  very  imperfect.  Indeed,  as  great  a 
confusion  has  prevailed  as  with  phenylic  acid,  a  body  whose  pro- 
perties exhibit  so  great  an  agreement  wTith  those  of  creosote  as  to 
give  rise  to  the  belief  that  they  were  both  identical,  and  that  the 
difference  only  depended  upon  some  accidental  impurities.  This  is 
the  view  which  has  been  more  and  more  developed  amongst  chem- 
ists, and  found  an  important  support  in  the  fact  that  the  substance 
mostly  found  at  present  in  commerce  under  the  name  of  creosote, 
is  nothing  else  than  impure  phenylic  acid,  and  isobtained  from 
coal  tar,  which  can  be  easily  proved  by  the  determination  of  its  boil- 
ing point,  and  its  behaviour  to  chloride  of  iron,  &c. 
The  creosote  which  I  examined  was  obtained  from  Batka,  of 
Prague,  who  prepares  it  extensively  from  wood  tar,  particularly 
from  that  of  beech  wood.  Its  characteristics  and  general  behaviour 
agree  completely  with  the  description  given  of  creosote  by  Eeichen- 
bach,  its  discoverer.  It  is  an  oily,  strongly  refracting,  slightly  yel- 
lowish fluid,  of  a  penetrating,  disagreeable,  smoky,  peculiar  odor, 
totally  distinct  from  that  of  phenylic  acid.  It  tastes  burning  sharp  ; 
produces  on  the  mucous  membrane  of  the  tongue  a  white  film.  In 
