ON  THE  MANUFACTURE   OF   RESIN  OIL  FROM  ROSIN. 
123 
still  is  then  closed  and  luted,  and  the  contents  raised  to  600°,  and 
maintained  at  this  point  until  the  process  is  completed.  The 
steam  is  introduced  through  the  lower  steam  pipe  when  the  tem- 
perature has  reached  300°,  and  through  the  upper  steam-pipe  when 
it  has  attained  to  600°.  The  oil  passes  off  in  vapor  to  the  worm, 
where  it  is  condensed  and  collected,  after  which  it  is  re-distilled  in 
the  same  manner,  caustic  lime  being  substituted  for  the  slaked 
lime  used  in  the  previous  process.  The  oil  thus  obtained  is  placed 
in  the  purifying  vessel  before  mentioned,  and  its  temperature 
raised  as  in  the  process  for  producing  painters'  oil.  This  oil  is 
stated  to  be  clear  and  pure,  entirely  free  from  acid,  and  forming 
an  excellent  curriers'  oil. 
A  lubricating  oil  for  the  uses  of  machinery,  &c,  is  obtained  by 
first  placing  the  oil  produced  at  550°  in  the  still,  with  about  five 
per  cent,  of  its  weight  of  slaked  lime  ;  the  man-hole  is  closed  and 
luted,  and  the  temperature  raised  to,  and  sustained  at  about  550°, 
until  the  process  is  completed.  The  steam  is  let  on  as  described 
in  making  tanners'  oil ;  and  the  oil  having  been  condensed,  is  re- 
distilled and  treated  in  exactly  the  same  way  as  tanners'  oil,  after 
which  it  is  run  into  the  purifying  vessel,  and  treated  as  before 
described.    It  is  thus  obtained  pure  and  limpid. 
Resin  oil  is  also  obtained  in  the  process  for  manufacturing  gas 
from  resin  ;  and  in  a  patent  granted  to  Mr.  Robertson  in  1848,  a 
claim  is  made  for  the  manufacture  of  a  spirit  (ethereal  oil)  trom 
resin  oil  thus  obtained.  This  is  the  same  as  the  naphtha  men- 
tioned above,  which  is  directed  to  be  purified  by  re-distillation 
once,  twice,  or  oftener,  in  combination  with  a  small  quantity  of 
lime,  until  it  attains  the  required  freedom  from  color,  three-quarters 
of  an  ounce  of  lime  being  used  to  each  pound  of  spirit. 
In  France,  M.  Dives  patented  in  1828  a  process  for  making  a 
drying  oil  with  resin  oil,  and  in  1838,  MM.  Payen  and  Huran 
patented  a  process  for  the  manufacture  of  a  lubricating  grease  by 
combining  lime,  potash,  or  soda,  more  particularly  the  former, 
with  resin  oil.  MM.  Fremy  and  Boutin  undertook  a  series  of 
investigations  with  regard  to  the  removal  of  the  pyrogenous  odor 
which  accompanies  resin  oil,  with  the  view  of  rendering  this  oil 
fit  for  the  manufacture  of  soap.  In  this,  however,  they  were  un- 
successful, and  we  are  not  aware  of  any  successful  attempts  to 
remove  the  odor  which  so  tenaciously  adheres  to  this  oil.  M. 
