122  Aromatic  Sulphuric  Acid,  etc.       f  am.  jocr.  pharm. 
March  1, 1871. 
Some  years  ago,  I  found  great  advantage  from  subjecting  tissues  to 
the  action  of  a  very  small  quantity  of  this  solution  in  glycerin,  and 
keeping  the  whole  at  the  temperature  of  100°  for  some  hours.  By 
this  process,  the  elements  of  the  tissues  were  softened,  and  could  be 
dissected  from  one  another  readily  for  examination  under  the  highest 
magnifying  powers. 
No  doubt  there  is  much  to  be  learnt  concerning  the  nature  of  the 
action  of  such  substances  upon  tissues  by  the  use  of  glycerin  solu- 
tions. For  microscopical  work,  glycerin  is  of  more  use  than  any 
other  medium.  Not  only  may  various  substances  be  removed  from 
tissues,  but  others  may  be  introduced,  and  the  tissue  subjected  to  the 
action  of  various  reagents  without  destroying  it.  In  fact,  the  action 
may  be  regulated  with  the  greatest  nicety.  Nearly  all  the  tests  re- 
quired in  microscopical  examination  may  be  dissolved  in  glycerin, 
("How  to  Work  with  the  Microscope,"  p.  297,  1867,)  and  tissues  of 
the  most  delicate  character  may  be  preserved  in  it,  and  will  retain 
their  microscopic  characters  for  years,  if  care  be  taken  to  obtain  the 
best  and  strongest  glycerin. — Lond.  Pharm.  Jour.,  Jan.  21,  1871, 
from  Nature. 
NOTES  ON  AROMATIC  SULPHURIC  ACID  AND  CONFECTION  OF 
SENNA. 
By  John  W.  Ehrman. 
Every  dispenser  is  acquainted  with  the  objections  which  may  be 
brought  up  to  the  present  officinal  formula  for  aromatic  sulphuric 
acid.  As  the  committee  on  the  revision  of  the  Pharmacopoeia  is  now 
in  session,  it  is  to  be  hoped  that  the  formula  under  consideration  may 
be  modified,  and  with  it  several  others  of  a  like  nature. 
The  aromatic  sulphuric  acid  is  used  most  extensively  as  a  solvent 
for  sulphate  of  quinia,  in  prescription,  usually  with  watery  or  syrupy 
vehicles.  When  prescribed  alone  for  the  medicinal  effects  of  the  acid, 
it  is  not  unfrequently  diluted  in  order  to  modify  its  taste,  and,  avoid- 
ing the  use  of  drops,  to  render  its  administration  more  convenient. 
Now,  when  the  elixir  of  vitriol  is  associated  in  this  manner  with 
watery  fluids,  the  coloring  and  extractive  matter  becoming  insoluble 
in  the  menstruum,  precipitates,  and  the  result  is  a  muddy  mixture,  in- 
stead of  the  clear  solution  we  should  otherwise  obtain.  But  the  elixir 
of  vitriol,  even  undiluted,  is  constantly  undergoing  change,  with  the 
continual  deposition  of  a  bulky  precipitate,  so  that  it  can  be  dispensed 
