258 
CHEMISTRY  OF  OIL  PAINTS. 
both  these  compounds  possess  the  constitution  of  compound 
ethers ;  thus  guaiacol  is  described  as  oxyphenate  of  methyl.  The 
empirical  formula  of  creas'ote  is  represented  as  Clfl,H10,O4. 
M.  Frisch  confirms,  in  general,  the  results  obtained  by  M. 
Gorup.  The  creasote  upon  which  he  operated  was  a  strongly 
refracting  liquid,  of  specific  gravity  of  1-0784.  It  was  per- 
fectly soluble  in  alcohol,  ether,  bisulphide  of  carbon,  as  well  as 
acetic  acid.  With  ammonia,  which  it  dissolved  slightly,  it  gave 
a  bluish-green  coloration,  which  changed  to  brown.  It  dissolved 
oxalic  acid  and  several  alkaloids.  With  potash  it  gradually 
became  brown,  and,  on  the  addition  of  ether,  developed  a  blue 
tint,  which  disappeared  on  agitation.  It  boiled  steadily  at  195° 
C.  (383°  F.)  With  nitric  acid  it  gave  picric  acid  ;  with  hydro- 
chloric acid  and  chlorate  of  potash  there  are  formed  nacreous 
scales,  consisting  of  chloranile  and  bichloroquinone.  With  sul- 
phuric acid  and  application  of  heat  it  gave,  after  neutralization 
with  baryta,  a  sulphosalt, — the  sulphophenisate  of  baryta  of 
Laurent, — soluble  in  alcohol  and  crystallizable.  In  the  presence 
of  bichromate  of  potash  this  sulphophenisic  acid  acquires  an 
agreeable  aromatic  odor. 
This  creasote  also  answered  to  the  test  alluded  to  above,  by 
giving  with  perchloride  of  iron  in  alcoholic  solution  a  green 
color. — Journ.  de  Pharm.  et  de  Chimie. — Lond.  JPharm.  Journ.' 
Feb.,  1868.  • 
CHEMISTRY  OF  OIL  PAINTS. 
Hjtherto  but  very  little  attention  has  ever  been  given  to  the 
above  subject  by  our  leading  chemists,  but  a  work  has  recently 
appeared,  published  by  the  celebrated  Dutch  chemist,  Mulder,  in 
which  a  vast  amount  of  useful  information  on  this  point  is  im- 
parted, and  much  of  the  mystery  oonnected  with  the  chemical 
action  of  the  different  paints  is  satisfactorily  explained.  The 
starting-point  of  his  investigations  was  an  inquiry  as  to  the  best 
material  to  protect  iron  from  rust.  The  result  has  been  his  re- 
jection of  all  paints  as  unlikely  to  answer  the  purpose,  and  his 
conclusion  that  coal  tar  contains  the  best  materials  for  a  pro- 
tecting coat.    The  author  very  completely  investigated  the  na- 
