488  PHARMACEUTICAL  OBSERVATIONS  ON  BUCHU. 
portion  of  the  carbonate  of  potassa  with  the  leaves  while  mace- 
rating, for  I  think  it  prevents  the  deposition  of  any  resinous 
matter  on  the  sides  of  the  vessel  during  the  evaporation,  which 
otherwise  takes  place,  producing  some  loss.  The  addition  of  al- 
cohol to  the  water  in  the  proportion  of  one-fourth  its  bulk,  was 
done  from  the  fact  that  many  vegetable  substances  are  more  easily 
percolated  when  the  acting  menstruum  contains  a  little  alcohol, 
and  the  above  proportions  have  been  found  to  answer  very  well 
in  practice.  Some  addition  of  this  kind  was  rendered  necessary 
on  account  of  the  mucilaginous  nature  of  the  plant  in  question, 
which,  otherwise,  is  ineligible  for  the  process  of  displacement,  as 
it  takes  place  very  slowly,  requiring  much  time  to  perfect  it. 
During  the  evaporation  of  the  alcoholic  and  watery  extract  a 
semi-fluid  matter  separates  on  the  top,  it  has  the  consistence  of 
coagulated  albumen,  is  of  a  dark  green  color  and  scarcely  any 
odor,  it  does  not  redissolve  in  the  liquid  from  which  it  separates. 
It  dissolves  slightly  in  cold  and  boiling  water,  is  less  soluble  in 
cold  and  boiling  alcohol,  and  entirely  insoluble  in  ether.  The 
watery  solution  of  this  was  of  a  yellowish  brown  color ;  sulphuric 
acid  changes  it  to  a  reddish  brown,  solution  of  sub-acetate  of  lead 
threw  down  a  copious  greenish  white  precipitate,  tannin  produced 
no  change ;  when  dry  it  is  brittle,  and  swells  up  when  macerated 
in  cold  water  for  a  length  of  time,  and  finally  dissolves. 
The  dose  of  this  fluid  extract  is  from  one  half  to  one  fluid  dram, 
t«  be  repeated  as  circumstances  require,  for  one  fluid  ounce  of 
extract  represents  an  ounce  of  the  leaves.  In  a  case  that  came 
under  my  notice  of  an  affection  of  the  kidneys,  it  was  used  in 
teaspoonful  doses  three  or  four  times  a  day,  and  at  the  end  of 
one  day  the  patient  experienced  considerable  relief  and  has  con- 
tinued to  use  it  ever  since  on  a  return  of  the  complaint.  The 
following  is  a  statement  of  another  case  of  Dr.  0.  H.  Taylor's, 
of  Camden,  N.  J.,  to  whom  I  presented  some  of  the  fluid  extract 
for  trial.  He  says  in  his  letter  to  me,  dated  Nov.  4th,  1853 : 
"  In  the  month  of  July  last,  I  was  requested  to  visit  Capt.  D** 
B*****,  aged  84  years.  At  the  time  of  my  visit  he  was  suffering 
from  a  painful  and  irritable  state  of  the  bladder,  with  frequent 
disposition  to  micturition,  and  occasionally  an  inability  to  pass 
water  for  several  hours ;  this  alternate  state  had  existed  with 
him,  more  or  less,  for  two  or  three  years.    From  the  history  of 
