122  Dr.  macbride’s  improved 
entirely  fubfide,  and  the  water  become  perfectly  limpid, 
and  clear  as  rock-water.  Your  lime-water  will  then  be 
fit  for  immediate  ufe. 
ix.  The  cock,  as  already  mentioned,  is  to  be  fixed  at 
leaft  twelve  inches  from  the  bottom  of  the  ciftern,  in 
order  that  only  the  limpid  part  of  the  lime-water  may 
run  off;  and  the  ufe  of  the  hole  in  the  bottom,  which  is 
ordered  to  be  flopped  with  a plug,  is  to  let  off  the  grofs 
and  infolublc  remains  of  the  lime,  as  often  as  it  may  be. 
found  neceffary  to  clean  out  the  ciftern. 
x.  When  the  firft  brewing  (as  it  may  be  termed)  of 
lime-water  is  all  expended,  you  are  to  fill  up  the  ciftern 
with  water  a fecond  time;  ftir  up  the  lime  from  the  bot- 
tom with  the  bucket  and  plunger,  fo  as  to  mix  it 
thoroughly  with  the  whole  body  of  the  water,  as  before 
directed,  and  then  leave  it  to  fubfide  for  the  requifite 
time.  Thus  you  will  have  a fecond  brewing  of  lime- 
water;  and  you  may  go  on  in  the  fame  manner  to  make 
a third,  fourth,  fifth,  or  perhaps  a fixth,  or  more  brew- 
ings, from  the  original  quantity  of  lime ; provided  you 
fhall  find  the  lime-water  continue  lufliciently  ftrong. 
xi.  There  are  two  ways  of  knowing  when  lime-water 
is  fufficiently  ftrong.  The  one  is  by  the  tafte,  and  this  a 
little  practice  will  teach  you  to  diftinguifh ; the  other  is, 
i by 
