Am.  Jour.  Pharm. 
June,  1899. 
Pharmacological  Notes. 
285 
cology  furnishes  a  verdict  from  which  there  can  be  no  reasonable 
appeal.  The  fact  is  that  the  eye  reacts  in  like  manner  to  both  these 
principles.  The  two  essential  ocular  phenomena  which  all  this 
alkaloidal  group  produce  in  varying  degree,  are  dilatation  of  the 
pupil  and  paralysis  of  the  small  muscle  within  the  eyeball,  whose 
function  it  is  to  accommodate  the  focus  of  the  eye  for  the  particular 
distance  at  which  it  may  be  working  at  any  given  moment.  This 
little  circular  muscular  band  is  known  as  the  muscle  of  accommoda- 
tion (or  ciliary  muscle).  The  paralyzing  action  of  the  mydriatics 
on  the  muscle  of  accommodation  is  shown  by  the  temporary  loss  of 
all  ability  to  read,  sew  or  do  any  other  fine  work  at  from  10  to  20 
inches  distance  for  a  period  varying  trom  one  hour  to  ten  days  from 
the  time  of  using  the  drug.  Now,  it  is  principally  in  their  power  to 
paralyze  this  muscle  that  the  solanaceous  alkaloids  differ  from  each 
other. 
As  to  hyoscin  and  scopolamin,  it  remains  to  be  said  that  there 
is  the  closest  conformity  in  the  mode,  rapidity,  duration  and  disap- 
pearance of  their  action  upon  the  healthy  human  eye. 
Assuming  the  use  in  each  eye  of  two  drops  (half  an  hour  apart) 
of  a  \  per  cent,  solution  of  hyoscin  hydrobromat  or  scopolamin 
hydrobromat,  in  either  case  : 
Dilatation  of  the'  pupil  will  begin  in  about  ten  minutes  and  reach 
its  maximum  in  about  50  minutes. 
The  (ciliary)  muscle  of  accommodation  will  begin  to  lose  its 
power  and  the  patient's  vision  for  near  objects  begin  to  fail  in  about 
thirty  minutes ;  it  will  be  entirely  lost  in  about  one  hour,  will  remain 
so  for  four  to  six  hours,  and  will  then  gradually  return  and  be 
completely  re-established  in  about  fifty-five  to  sixty  hours.  These 
figures  are  the  result  of  my  own  experiments  with  the  two  drugs 
on  a  human  eye  that  was  as  close  an  approach  to  mathematical 
perfection  as  we  find  anywhere  in  Nature,  and  my  own  findings  are 
substantiated  in  the  main  by  those  of  Schmidt,  E.  Merck,  Meyer 
and  E.  Emmert.  Therefore,  while  we  cannot  say  as  yet  that 
hyoscin  and  scopolamin  are  chemically  identical,  there  is  not  one 
point  lacking  in  the  pharmacologic  evidence  to  show  that  for  all 
practical  purposes  of  pharmacist  and  physician  they  are  identical 
of  effect  (pharmacologically  identical),  and,  therefore,  entirely  inter- 
changeable. And  while  substitution  is  not  only  the  violation  of  a 
sacred  trust  between  the  druggist  and  the  physician,  but  is  ethically 
