368  PRESERVATION  OF  SULPHURETTED  HYDROGEN  SOLUTION. 
thus  left  stranded  on  the  surface  in  intimate  combination.  In 
proportion  as  the  ether  passes  off",  the  blood  or  the  secretion  of 
the  surface  permeate  the  tannin  and  cotton ;  but  tannin  acts 
directly  upon  albumen,  coagulating  it,  and  transforming  it  into  a 
kind  of  membrane,  almost  like  leather.  The  cotton  meanwhile 
unites  the  whole,  gives  substance  to  the  mass,  and  adhesive 
quality.  When  all  is  solidified,  the  dressing  becomes,  in  fact,  a 
concrete,  having  a  true  organic  hold  or  basis  on  the  tissue  ;  and 
as  the  tannin,  if  the  solution  be  freely  applied,  is  in  excess,  any 
new  exudative  matter  or  blood  is  for  several  hours  taken  up  by 
it,  and  the  annealing  is  made  the  more  complete. 
44  Thus  by  this  dressing,  the  air  is  excluded  from  every  pos- 
sible point  in  every  possible  direction,  not  by  a  mere  septum,  but 
by  the  combination  of  the  animal  fluids  with  the  remedy ;  and 
because  the  air  is  excluded  and  fluid  is  absorbed  there  is  no  de- 
composition— i.  e.  no  oxidation  ;  and  because  there  is  no  oxida- 
tion there  is  no  irritation. 
"  The  styptic  and  adhesive  qualities  of  this  fluid  are  easily 
demonstrated  by  observing  its  direct  action  on  blood,  on  serum, 
on  pus,  on  albumen.  You  will  see  that  it  solidifies  all  these  by 
mere  contact  with  them. 
"  To  these  properties  I  must  also  add  that  of  complete  deodori- 
zation.  Here  is  putrid  blood,  here  putrid  ovarian  serum,  here 
putrid  purulent  substance.  They  are  unapproachable  when  laid 
on  an  open  surface,  but  we  bring  them  into  contact  with  the  so- 
lution, and  they  are  deodorized.  Further,  the  decomposed  sub- 
stance is  fixed  by  the  tannin  and  rendered  inert. — Med.  Times 
and  G-az. — Dental  Cosmos,  June,  1867. 
PRESERVATION  OF  SULPHURETTED  HYDROGEN  SOLU- 
TION IN  THE  LABORATORY. 
At  the  last  meeting  of  the  Pharmaceutical  Society  of  Paris, 
M.  Lepage,  of  Grisors,  brought .  forward  a  process  which  he  has 
adopted  for  preserving  solutions  of  sulphuretted  hydrogen. 
All  chemists  know  that  this  useful  reagent  cannot  be  pre- 
served long  in  aqueous  solution.  The  author  has  adopted  for 
some  years  an  artifice  which  enables  sulphuretted  hydrogen  solu- 
tion to  be  kept  for  twelve  or  fifteen  months  with  scarcely  any  loss 
