1 12  Dr.  m a cb ride’s  improved 
them,  in  the  way  of  premium,  to  fet  the  bufinefs  a-go- 
ing, fo  ftrong  are  the  prejudices  amongft  tradefmen  of 
all  forts  againft  trying  new  pradtices,  and  fuch  the  re- 
luctance with  which  they  quit  their  ancient  ways  of 
working. 
I am,  Sec. 
YOU  may  pleafe  to  remember  that  I informed  you, 
fome  years  ago,  of  my  having  found  out  a way  of  tan- 
ning  leather  in  lefs  time,  and  at  a fmaller  expence  of 
materials,  than  can  be  done  by  any  of  the  ways  hitherto 
known  or  pradtifed;  and  promifed  that,  as  foon  as  I 
fhould  find  myfelf  at  liberty  to  difclofe  it,  I would  com- 
municate my  method  to  the  Royal  Society. 
Accordingly  I take  the  liberty,  of  inclofing  a fet  of 
infiruclions,  which  I drew  up  for  the  perfon  who  con- 
cluded the  bufinefs  of  a large  tan-yard  belonging  to  a 
company  with  which  I have  had  an  engagement  for. 
thefe  laft  four  years;  which  I apprehend  will  be  found 
fuffi- 
