ON  THE  UNCERTAINTY  OF  PHARMACEUTICAL  PREPARATIONS.  157 
preparations  more  acceptable  to  the  palate  of  the  patient.  An  in- 
finite number  of  proximate  principles  have  been  produced,  some 
deserving  a  trial  at  the  hands  of  the  physician,  others  no  doubt 
may  be  considered  almost  useless ;  but  amongst  the  new  pharma- 
ceutical preparations  we  believe  that  one  of  the  best  forms  for  the 
concentrated  medicines  of  vegetable  origin  is  that  of  fluid  extract. 
We  will  state  some  of  the  objections  which  are  urged  against  tinc- 
tures, decoctions,  &c,  and  the  advantages  of  fluid  extracts  over 
other  preparations. 
The  objections  to  the  administration  of  tinctures  are  that,  in 
many  cases,  their  long  continued  use  in  chronic  affections  is  apt  to 
result  in  habits  of  confirmed  intemperance,  together  with  the  fact 
that  the  stimulating  properties  of  the  Alcohol  frequently  over- 
balance the  benefit  derived  from  the  employment  of  the  remedy. 
This  is  particularly  the  case  where  the  dose  of  the  medicine  is 
large,  as  in  the  Compound  Tincture  of  Gentian,  Compound  Tinc- 
ture of  Senna,  &c.  Another  objection  which  is  urged  against  them 
is,  that  when  prepared  with  proof  spirits  or  diluted  Alcohol  they 
undergo  after  a  time  the  acetous  fermentation,  by  the  conversion 
of  the  Alcohol  into  Acetic  acid,  by  the  catalytic  influence  of  the 
nitrogenous  matter  in  solution,  and  which  greatly  impairs  the 
power  of  the  agent.  This  is  particularly  the  case  with  the  tinc- 
tures of  Senna,  Rhubarb,  Colombo,  Hyoscyamus,  Digitalis,  Cin- 
chona, Hops,  Aloes,  and  the  Compound  Tincture  of  Cardamom. 
Decoctions,  by  the  influence  of  the  air  and  the  mutual  reaction 
of  their  components,  decompose  in  a  very  short  space  of  time,  and 
if  the  active  principle  be  volatile,  it  will  be  dissipated,  thereby 
rendering  them  inert.  Infusions,  too,  spoil  very  soon,  especially 
in  warm  weather,  and  are  subject  to  many  of  the  objections  urged 
against  decoctions. 
It  is  not  an  uncommon  occurrence,  in  private  practice,  for  a  phy- 
sician to  direct  an  infusion  of  Rhubarb  or  Senna  to  be  given  to  his 
patient — but  instead  of  infusion,  a  decoction  will  be  prepared,  and 
probably  "  to  get  out  all  the  strength  "  the  root  or  leaves  will  be 
kept  boiling  for  an  hour  or  two,  and  the  effect  is  obvious :  instead 
of  a  gentle  laxative,  in  the  case  of  Rhubarb,  you  have  a  prepara- 
tion of  the  opposite  character,  and  Senna  will  be  found  to  possess 
all  of  its  griping  qualities  in  perfection,  with  very  little  of  its 
cathartic  powers. 
