386 
PHARMACEUTICAL  NOTES. 
the  plaster  is  finished  in  a  shorter  time ;  but  this  is  fully  com- 
pensated by  the  little  attention  required,  and  the  improved  qual- 
ity of  the  product.  A.  Graf,  in  a  late  number  of  "  Buchner's 
Repertorium,"  advocates  a  similar  process,  which  requires,  how- 
ever, that  the  mixed  litharge  and  oil  be  added  to  the  remainder 
of  the  oil  previously  heated ;  this  preliminary  heating,  in  my 
experience,  is  not  necessary. 
Soap  Plaster. — In  preparing  this  plaster,  the  soap  is  rubbed 
with  water  to  a  semifluid  consistence,  and  then  stirred  into  the 
melted  plaster.  It  is  difficult,  however,  to  rub  the  soap  up  per- 
fectly and  rapidly,  and  I  therefore  found  it  convenient  to  strain 
the  mixture,  obtained  by  triturating  the  soap  with  its  weight  of 
water,  through  coarse  muslin,  and  to  reduce  the  residue  with  a 
proportionate  amount  of  water,  before  stirring  it  into  the  plaster. 
This  procedure  insures  a  perfectly  smooth,  uniform  plaster.  It 
may  seem  trifling  to  draw  attention  to  so  insignificant  a  matter  ; 
but  these  little  advantages  frequently  save  much  trouble,  for 
which  reason  it  is  here  noted. 
Oil  of  Turpentine. — A  short  time  ago,  I  received  from  a 
wholesale  firm  in  this  city  a  sample  of  oil  of  turpentine,  which 
was  of  a  pale  green  color,  evidently  contained  copper,  and  was 
consequently  unfit  for  sale.  I  am  informed  that  this  is  not  an 
isolated  case,  but  that  oil  in  a  similar  condition  has  been  met 
with  before.  The  copper  was  readily  removed  by  shaking  the 
oil  with  a  small  amount  of  a  saturated  solution  of  prussiate  of 
potash,  and  allowing  it  to  rest  for  two  to  three  days,  when  it  was 
drawn  off  clear. 
Syr.  of  Phospli.  of  Iron,  Qwinia  and  Strychnia,  so  highly 
recommended  by  Drs.  Aitken  and  Lyons  as  a  powerful  tonic 
combination,  has  of  late  come  into  considerable  use  in  this  city, 
but  unfortunately  is  very  unstable.  Several  of  our  leading 
pharmacists,  who  prepared  the  syrup  according  to  the  formula 
published  in  A.  J.  Ph.,  March,  1867,  p.  177,  and  manipulated  as 
suggested  by  Mr.  Chas.  Bullock,  found  that  in  a  short  time  it 
deposited  a  white  precipitate,  and  soon  became  dark-colored.  I 
have  not  given  the  subject  sufficient  attention  to  point  out  a  reli- 
able means  of  avoiding  this,  but  would  suggest  that  the  syrup  be 
