288 
Tincture  of  Hyoscyamus. 
Am.  .lour.  Pharm. 
May,  1884. 
his  investigations  to  pharmacy,  he  points  out  not  only  what  I  have 
just  shown  as  regards  the  turbidity  test,  but  goes  on  also  to  deduce 
several  conclusions  from  it  which,  according  to  my  experience,  will,  I 
think,  scarcely  stand  the  test  of  experiment.  He  states,  for  example, 
that  "  many  samples  of  tincture  of  henbane  almost  lose  their  property 
of  becoming  turbid  with  water;  this  is  generally  the  result  of  age,  for 
such  a  tincture  will  be  found  to  have  lost  its  original  green  color  and 
changed  to  a  brown  with  formation  of  the  usual  dark  deposit.  Thus 
deposition  and  disappearance  of  turbidity  are  simultaneous  and  pro- 
portionate. As  to  the  nature  of  the  deposit  in  the  tincture,  I  believe 
if  examined  it  will  be  found  to  consist  of  a  mixture  of  odorous  prin- 
ciple, fat  and  chlorophyll,  the  separation  of  which  is  slowly  effected  by 
the  agency  of  the  water  in  the  proof  spirit ;  if  this  be  so,  then  it  is  an 
argument  for  the  use  of  a  stronger  alcohol  in  the  making  of  the  tinc- 
ture of  henbane." 
I  called  Mr.  Gerrard's  attention  to  the  fact  that  I  had  exposed  a 
tincture  of  henbane  to  ordinary  light  (no  sunshine),  and  in  three  weeks 
it  had  lost  almost  every  trace  of  green  coloring  principle,  while  it  had 
not  deposited  in  the  least,  nor  had  it  lost  its  property  of  becoming 
turbid  with  water.  To  this  Mr.  Gerrard  replied  that  the  tincture  had 
not  been  kept  sufficiently  long,  but  that  with  the  changing  of  the 
chlorophyll  the  tincture  would  have  become  acid  (it  shows  no  signs  of 
acidity  up  to  the  present  time),  this  acidity  increasing  with  age,  and 
that  the  deposit  referred  to  by  him  would  take  from  three  to  six 
months  to  form.  I  believe  Mr.  Gerrard  is  quite  right  in  his  observa- 
tions, although  I  think  he  is  wrong  in  his  deduction  that  this  change 
"  is  slowly  effected  by  the  agency  of  the  water  in  the  proof  spirit." 
Some  years  ago  I  pointed  out  that  these  very  changes  here  described 
by  Mr.  Gerrard  took  place  in  olive  oil  on  exposing  it  to  light.  There 
was  the  first  gradual  decomposition  of  the  chlorophyll  and  the  disap- 
pearance of  the  bands  in  the  spectroscope;  next  an  increasing  cloudi- 
ness in  the  oil,  accompanied  by  an  increasing  acidity,  all  of  which,  I 
have  no  doubt,  would  have  ended  in  a  deposit  as  described  by  Mr. 
Gerrard  had  the  density  of  the  oil  permitted  this,  or  had  it  been  kept 
long  enough.  The  water  could  scarcely  in  this  instance  be  said  to  be 
the  agent  which  either  favored  decomposition  or  tended  to  effect  sepa- 
ration. But  further  and  more  important  still,  I  have  to  point  out  the 
much  greater  susceptibility  of  a  tincture  of  henbane  to  change  when 
prepared  with  a  stronger  as  compared  with  a  weaker  alcohol.    I  have 
