^-iuZ'^^'"'^'}-    ^harmacopceia  of  the  Philadelphia  Hospital.  423 
slightly,  and  of  22  years  hardly  at  all.  Hydrogen  peroxide  acts 
more  slowly  but  gives  more  definite  results.  When  writing  ink  is 
thus  bleached,  most  of  the  iron  contained  therein  remains  mor- 
danted with  the  fibres  of  the  paper,  consequently  writing  so  tampered 
with  can  be  restored  by  the  application  of  gallic  or  tannic  acid.  In 
determining  the  age  of  any  particular  writing,  the  following  pre- 
cautions should  be  observed  : — (1)  The  inks  must  be  those  known  as 
ordinary  writing  inks  prepared  from  iron  and  chromium  salts  and 
galls.  (2)  Writing  dried  by  means  of  blotting-paper  is  more  easily 
removed  than  writing  which  is  allowed  to  dry  on  the  surface  of  the 
paper.  (3)  The  bleaching  solution  must  be  exceedingly  dilute,  other- 
wise the  action  is  so  rapid  and  powerful,  that  both  old  and  new 
writings  are  removed  almost  simultaneously.  (4)  The  action  must  be 
carefully  watched  so  as  not  to  be  too  long  continued.  (5)  Very 
old  writing  which  has  become  brown  by  age,  although  it  resists  the 
action  of  weak  solutions  of  bleaching  powder  and  hydrogen  peroxide, 
will  show  signs  of  giving  way  almost  instantly  when  acted  on  by 
dilute  nitric,  hydrochloric,  or  oxalic  acids. 
PHARMACOPCEIA  OF  THE  PHILADELPHIA  HOSPITAL. 
{Continued  from  page  317.) 
Pulveres  Bismuthi  et  Opii. 
Each  powder  contains : 
Bismuth  Subnitrate   gr.  x . 
Powd.  Opium   gr.  j. 
Dose :  One  powder 
Pulvis  Catarrhal. 
Morphine  Hydrochlor   gr.  J. 
Powd.  Acacia   gr.  xxx. 
Powd.  Talc   3  jss. 
Bismuth  Subnit   Sjss. 
Use ;  Insufflate  into  nostrils. 
Pulveres  Rhei  et  Gentianse. 
Each  powder  contains ; 
Powd.  Rhubarb, 
Powd.  Gentian, 
Powd.  Ginger   aa    gr.  iij. 
Sodium  Bicarbonate   gr.  x. 
Dose  ;  One  or  more  powders. 
SACCHARA. 
(Aromatic  Diluents  for  Powders.) 
Saccharum  Anisi. 
Oil  of  Anise   q.  s. 
Acacia   gj. 
Sugar  of  Milk  q.  s.  ad  gj. 
Saccharum  Carui. 
Oil  of  Caraway,  q.  s.  etc.,  etc. 
Saccharum  Cinnamomi. 
Oil  of  Cinnamon,  q.  s.,  etc.,  etc. 
Saccharum  Foeniculi. 
Oil  of  Fennel,  q.  s.,  etc..  etc., 
Saccharum  Menthx  Piperitse. 
Oil  of  Peppermint,  q.  s.  etc.,  etc. 
