THE  GUMS  AND  RESINS  OF  COMMERCE. 
137 
are  easily  prepared  and  applied,  dry  quickly  and  are  free  from 
unpleasant  smell;  they  are  used  for  articles  of  furniture  and 
musical  instruments. 
The  resins  which  enter  into  their  composition  are  seedlac, 
benzoin,  anime,  or  thus.  The  varnishes  made  with  essential  or 
volatile  oils  are  chiefly  used  for  pictures — caoutchouc,  and  oil  of 
turpentine,  (turps,  as  it  is  familiarly  termed,)  enter  into  their 
composition.  Fixed  oil  or  fat  varnishes  dry  easily,  at  common 
temperatures,  and  form  a  solid  and  nearly  colorless  glazing  suited 
for  coach  panneling  and  house  painting. 
The  fine  copal  varnishes  do  not  dry  so  readily  as  if  mixed  in 
the  proportion  of  three  parts  of  anime  and  one  of  copal.  Oil 
varnishes  require  to  be  kept  a  considerable  time  to  ripen,  as  it  is 
technically  termed,  before  they  are  fit  for  use,  the  time  varying 
from  three  to  twelve  months,  according  to  the  purpose  for  which 
they  are  intended,  in  order  that  the  driers  and  other  feculencies 
may  be  deposited  and  the  varnish  become  bright  and  trans- 
parent. 
Varnishes  are  very  extensively  employed  in  the  arts  and  for 
domestic  purposes.  When  we  consider  the  large  number  of 
vehicles  in  use  of  various  kinds,  the  superior  classes  of  which,  as 
private  coaches,  omnibuses  and  cabs,  railway  carriages,  and  the 
paint- work  of  ships'  cabins,  houses,  and  household  furniture,  pic- 
tures, &c,  all  require  varnish,  we  shall  be  able  to  form  some  slight 
idea  of  the  consumption.  The  tenders  for  one  railway  company 
alone,  the  London  and  North  Western,  are  for  1500  gallons  at 
a  time.  Gold  and  bronze  lackering,  and  varnish  for  stoves,  &c, 
are  other  u^es.  The  recent  permission  to  use  methylated  spirit 
in  the  manufacture  of  varnish,  free  of  duty,  bringing  down  the 
price  some  10s.  to  12$.  a  gallon,  will  give  even  a  further  stimulus 
to  the  demand  for  resins,  and  probably  lead  to  the  more  general 
employment  of  varnishes  for  wood-work  instead  of  paint. 
According  to  Thunberg,  the  very  best  Japan  varnish  is  pre- 
pared  from  Rhus  vernifera,  which  grows  in  great  abundance  in 
many  parts  of  that  country,  and  is  likewise  cultivated  in  many 
places  on  account  of  the  great  advantages  derived  from  it.  This 
varnish,  which  oozes  out  of  the  tree  on  being  wounded,  is  pro- 
cured from  stems  that  are  three  years  old,  and  is  received  in  some 
proper  vessel.     At  first  it  is  of  a  lightish  color,  and  of  the 
