372 
PREPARATION  OF  SAVIN  CERATE,  ETC. 
into  it,  and  left  standing  for  about  36  or  40  hours  at  a  tempera- 
ture of  45  to  50°  F.  The  cotton  is  now  well  washed  with  cold 
water  and  pressed  between  folds  of  blotting  paper,  to  remove  as 
much  of  the  humidity  as  possible.  This  cotton  dissolves  very 
quickly  in  a  mixture  of  ether  and  alcohol.  Freshly  prepared 
collodion  cotton,  as  long  as  it  is  damp,  will  dissolve  quicker  and 
better  than  old,  which  is  quite  dry.  If  the  cotton  is  left  too  short 
a  time  in  the  acid  mixture,  it  gives  a  preparation  not  entirely 
soluble  in  the  ether  mixture ;  on  the  contrary,  a  longer  standing 
with  the  acid  mixture  has  never  proved  injurious,  either  to  the 
dissolving  or  other  qualities  of  the  cotton.  I  obtained  an  excel- 
lent preparation,  entirely  and  quite  easily  dissolving  in  the  ether 
mixture,  by  leaving  the  cotton  for  nine  days  in  the  mixture  of 
nitric  and  sulphuric  acids. 
Whenever  the  acids  are  too  strong  or  not  strong  enough,  the 
cotton  will  not  dissolve  in  the  ether  mixture.  By  using  strong 
fuming  Nordhausen  sulphuric  acid  of  1.86  sp.  gr.  mixed  with 
nitric  acid,  or  with  nitrate  of  potash,  the  cotton  is  converted  into 
a  very  excellent  gun  cotton,  but  being  insoluble  in  ether,  it  can- 
not be  used  for  collodion.  Both  collodion  and  gun  cottons  can 
be  kept  for  any  length  of  time  without  being  decomposed,  if 
proper  care  has  been  taken  to  remove  all  the  acid  by  washing 
freely  with  water. — Journ.  and  Trans.  Maryland  OoL  Pharm., 
June,  1858, 
Baltimore,  December,  1857. 
ON  THE  PREPARATION  OF  SAVIN  CERATE,  AND  THE  FLUID 
EXTRACT  OF  SAVIN, 
By  I.  J.  Grahame. 
Read  before  the  College,  March  6th,  1857. 
The  formulae  of  the  several  Pharmacopoeias  for  the  prepara- 
tion of  Savin  Cerate  are  all  more  or  less  objectionable.  That 
of  our  own  Pharmacopicea,  while  it  produces  a  tolerably  efficient 
ointment,  rendered  so  to  a  great  extent  by  the  employment  of 
Resin  Qerate  as  the  fatty  base  of  its  composition,  is  an  inelegant 
preparation  on  account  of  the  use  of  the  powder  of  Savin  in  a 
state  of  incorporation ;  to  obtain  which,  in  the  requisite  degree 
of  division,  it  is  necessary  to  be  submitted  to  the  drying  process. 
