4i8 
Standard  Surgical  Dressings. 
(  Am.  Jour.  Pharm. 
(   Sei)teml)fr,  1911. 
or  gauze  not  impregnated  with  an  antiseptic,  there  is  possibly  an 
opportunity  for  the  Pharmacopoeia  or  the  National  Formulary  to 
establish  certain  standards. 
I  have  discussed  this  question  at  some  length  (Journal  of  the 
Society  of  Chemical  Industry,  October  31,  T904).  Here  1  have 
called  attention  to  the  fact  that  the  Pharmacopieial  standards  thus 
noted  were  open  for  criticism. 
In  respect  to  the  standards  of  the  United  States  Pharmacopoeia, 
among  its  faults  are  the  tests  for  absorbency.  Absorbent  cotton, 
even  when  heavily  charged  with  impurities,  will,  when  pressed  in 
the  hand  and  placed  on  the  surface  of  water,  sink.  The  Pharmaco- 
poeia is  very  indefinite  as  to  the  amount  of  water  to  be  used.  The 
United  States  Pharmacopoeia  has  it  that,  when  purified  cotton, 
previously  pressed  in  the  hand,  is  placed  on  the  surface  of  cold  water, 
it  will  absorb  the  water  and  sink,  and  the  water  should  not  acquire 
an  acid  or  alkaline  reaction. 
The  test  of  sinking  in  water  is  a  test  neither  of  purity  nor  absorb- 
ing power.    Soap  or  glycerine  will  increase  the  apparent  absorbency. 
•  The  following  has  been  suggested  by  me  as  a  more  rational 
Pharmacopoeial  standard  for  puiified  or  absorbent  cotton,  and  these 
standards  are  those  to  which  the  leading  brands  now  on  the  market 
will  be  found  to  comply.  In  other  words,  they  are  standards  which 
are  attainable,  and  which  will  exclude  cottons  of  a  low  grade  or  to 
which  foreign  substances  have  been  added : 
GossYPiuM  Purification. 
Purified  Cotton. 
Suggested  Standard. — The  hairs  of  the  seed  of  Gossypium 
(Fam.  Malvaceoe)  freed  from  adhering  impurities  and  deprived 
of  fatty  matter. 
White,  soft,  fine  filaments,  appearing  under  the  microscope  as 
hollow,  flattened  and  twisted  bands,  spirally  striate,  and  slightly 
thickened  at  the  edges  ;  inodorous  and  tasteless  ;  insoluble  in  ordinary 
solvents,  but  soluble  in  an  ammoniacal  solution  of  cupric  oxide. 
When  purified  cotton,  previously  compressed  in  the  hand,  is 
thrown  on  the  surface  of  cold  water,  it  should  readily  absorb  the 
latter  and  sink. 
