126  Dr.  macp, ride’s  improved 
fo  far  from  tending  to  rot  the  leather,  it  gives  unufual 
firmnefs ; and  the  foals  which  are  railed  by  the  vitriolic 
fouring  are  remarkably  found,  and  always  free  from  the 
flighted:  degree  of  rottennefs.  Befides,  the  fame  four 
may  do  for  many  parcels  of  leather,  by  adding  a little 
vitriol  to  it;  and  it  need  only  be  thrown  away,  when  it 
becomes  too  dirty  for  ufe,  by  the  frequent  fuccefiion  of 
hides. 
xvm.  A wine  pint  of  the  ftrong  fpirit  of  vitriol, 
which  will  not  colt  more  than  nine  or  ten  pence^,  is 
fufficient  for  fifty  gallons  of  water  to  prepare  the  fouring 
at  firlt:  therefore  all  you  have  to  do,  in  railing  the  foals, 
is  only  to  prepare  them  before-hand  in  the  ufual  way ; 
* 
and,  when  they  are  fitted  for  the  fouring,  mix  up  a quan- 
tity of  vitriol  and  water,  according  to  the  number  of 
hides  that  you  require  to  have  raifed,  Hill  obferving  the 
proportion  of  a pint  to  fifty  gallons,  which  will  be 
enough,  if  the  vitriol  be  of  the  due  degree  of  ftrength. 
The  hides  may  lie  in  the  fouring  till  you  find  them  fuf- 
ficiently  raifed,  for  they  will  be  in  no  danger  of  rotting, 
as  they  would  be  in  the  common  corn  fourings,  which 
in  time  might  turn  putrid,  and  rot  the  leather;  whereas, 
the  vitriolic  fouring  keeps  off  putrefaction. 
(a)  The  oil  of  vitriol  is  fold  by  the  clrnggifts  in  large  bottles,  containing 
(eight  or  ten  gallons, 
xix.  When 
