SULPHUROUS  ACID. 
241 
SULPHUROUS  ACID. 
By  0.  Umney,  F.O.S. 
The  introduction  into  the  British  Pharmacopseia  of  remedial 
agents  of  whose  therapeutic  value  comparatively  little  was  pre- 
viously known,  has  been  the  means  of  giving  to  medical  practi- 
tioners new  material  for  research  ;  and  has  undoubtedly  resulted 
in  promoting  investigations  which  otherwise  would  never  have 
been  attempted. 
The  action  of  sulphurous  acid,  a  remedy  of  antiquity  now 
placed  in  the  Pharmacopoeia,  had  been  much  less  studied  than 
it  apparently  deserved,  for  recently  most  beneficial  results  have 
followed  its  use  in  affections  of  the  throat,  by  means  of  the  spray 
producer,  as  recommended  by  Dr.  Dewar,*  whose  experiments 
with  this  body  in  various  forms  of  disease  seem  to  have  been 
most  successful ;  also  used  to  some  extent  by  Mr.  Hamilton, 
Surgeon  to  the  Liverpool  Infirmary,  in  cases  of  typhoid  or 
enteric  fever  ;t  the  results  of  whose  experiments  have  been  con- 
firmed by  Dr.  Jones  of  Liverpool. |  The  latter  gentlemen  both 
used  a  solution  professedly  of  the  Brit.  Pharm.  strength  ;  Dr. 
Dewar,  a  more  dilute  solution,  not  exceeding  4  per  cent,  of  real 
sulphurous  acid. 
For  some  time  past  I  have  observed  that  the  solution  of  sul- 
phurous acid,  as  supplied  by  manufacturers,  variously  labelled 
"  Sulphurous  Acid,  Solution  of  Sulphurous  Acid,  Sulphurous 
Acid,  B.  P.,"  has  very  much  difiered  from  the  acid  as  described 
by  the  Pharmacopoeia,  which  is  defined  as  having  a  spec.  grav. 
of  1*040,  and  containing  9*2  per  cent,  of  real  sulphurous  acid. 
The  commercial  solutions  I  examined  varied  in  strength  from 
2  to  6  per  cent. ;  none  approached  the  high  standard  of  the 
Pharmacopoeia. 
It  was  quite  obvious  that  this  deficiency  did  not  arise  from 
any  attempt  to  make  a  preparation  of  inferior  quality  with  such 
a  body  as  sulphurous  acid, — used  as  it  is  daily  in  the  arts  in 
enormous  quantity  as  a  cheap  bleaching  agent,  and  moreover  as 
*  Dr.  Dewar's  Pamphlet  on  Sulphurous  Acid, 
t' Lancet/  vol.  i,  1869,  p.  45. 
J/fc^'d.  p.  126. 
•  16 
