ri  8 Dr.  mac  bride’s  improved 
All  this,  I will  venture  to  fay,  can  be  done  by  pur- 
fuing  the  method  which  is  laid  down  in  the  inclofed 
paper,  and  which  may  be  introduced  into  any  common 
tan-yard. 
With  refpeet  to  time  it  is  poffible,  in  the  way  that  I 
have  found  out,  to  finifh  leather  in  a fourth  part  of  what 
is  required  in  the  ordinary  procefs;  for  I have  repeatedly 
had  calf-fkins  tanned  in  a fortnight  or  four  weeks,  which 
in  the  common  way  could  not  be  done  in  let's  than  from 
two  to  four  months. 
I lhall  not  pretend,  however,  to  affirm,  that  that  bufi- 
nefs  can  be  carried  on  in  the  large  way  with  fuch  expe- 
dition; becaufe  a great  deal  of  this  abridgement  of  time 
was  probably  owing  to  frequent  handling  and  working 
of  the  leather;  but  I am  confident,  and  know  it  from 
four  years  experience,  that  in  the  ordinary  courfe  of  bu- 
finefs,  and  in  a common  tan-yard,  the  tanner  may  fave 
at  leaf!  four  months  out  of  twelve,  produce  better  lea- 
ther, and  find  his  bark  go  much  farther  than  in  the  old 
way  of  tanning. 
Having  premifed  thus  much,  I flatter  myfelf  that  the 
paper  of  inftrudtions  will  be  found  perfectly  intelligible. 
It  fhews,  that  the  principles  on  which  my  method  is  efta- 
blifhed  are  derived  from  chemiftry,  and  therefore  it  will 
not 
