Am.  Jour.  Pharm.  \ 
November,  1917.  > 
Antiseptics  and  the  War. 
489 
Eupad  —  Solution  of  Eusol  —  and  Hypochlorous  Acid. — 
While  Dakin  and  Carrel  were  attempting  to  prepare  a  satisfactory 
hypochlorite  antiseptic  solution,  Prof.  J.  L.  Smith  and  his  asso- 
ciates, of  the  University  of  Edinburgh,  found  that  free  hypochlorous 
acid  was  a  more  active  antiseptic  than  its  salts.  Its  bactericidal 
value  was  high  and  it  also  possessed  the  advantage  of  not  coagulating 
albuminous  matter.  To  effect  a  complete  liberation  of  the  hypo- 
chlorous acid,  they  first  prepared  a  powder  by  intimately  mixing 
equal  parts  of  finely  ground  chlorinated  lime  and  boric  acid.  This 
was  named  eupad. 
Solution  of  eusol  was  made  by  mixing  25  Gms.  of  eupad  with 
one  liter  of  water,  allowing  the  mixture  to  stand  for  3  or  4  hours, 
then  siphoning  off  the  supernatant  liquid  and  filtering  the  remainder, 
to  rid  it  of  the  insoluble  calcium  borate.  The  filtrate,  solution  of 
eusol,  contains  some  calcium  chloride  and  about  .5  per  cent,  of  free 
hypochlorous  acid,  which  corresponds  to  about  .34  per  cent,  of  avail- 
able chlorine. 
Still  later,  Drs.  Beattie,  Lewis,  and  Gee  succeeded  in  preparing 
hypochlorous  acid  electrically  from  hypertonic  saline  solution.  The 
apparatus  used  is  ingenious  and  simple  and  can  readily  be  fixed  up 
in  any  hospital  or  laboratory.  For  further  reference,  the  reader  is 
referred  to  their  original  article  in  the  British  Medical  Journal  (Feb. 
24,  1917,  page  256). 
Dakin-Carrel  Solution. — Drs.  Dakin  and  Carrel  began  their 
work  in  Prof.  Triffrer's  laboratory,  in  Paris,  in  December,  1914,  to 
overcome  the  problems  that  confronted  the  medical  units  in  this 
war.  They  tested  hundreds  of  chemicals  before  their  hypochlorite 
solution  was  perfected  in  June,  191 5,  which  was  destined  to  become 
one  of  the  most  successful  antiseptics  ever  put  forth. . 
The  formula,  technique  and  mode  of  preparation  of  the  solution 
have  been  published  in  the  leading  scientific  journals  and  it  would 
be  useless  to  rewrite  them  here.  However,  I  may  mention  that 
Dakin's  original  formula,  containing  boric  acid,  has  been  replaced 
by  Dufrasne's  modification,  in  which  boric  acid  is  excluded,  and 
sodium  bicarbonate,  anhydrous  sodium  carbonate,  chlorinated  lime 
and  water  are  the  revised  ingredients  (this  solution  being  known  as 
Neutral  Dakin-Carrel  Solution).  Though  some  laboratories  market 
a  concentrated  hypochlorite  solution  and  advise  the  dilution  and 
neutralization  of  the  alkalinity  with  boric  acid  before  use,  it  is  inad- 
visable to  follow  such  procedure  as  some  have  reported  rather 
