66  Prescription  Clamps.  {Am£C™srm' 
much  temptation  for  adulteration;  it  would  be  advisable  to  use  it  alto- 
gether, when  we  would  always  have  a  uniform  and  reliable  preparation. 
As  it  is  now,  one  can  hardly  find  two  samples  alike. 
In  making  green  soap,  one  or  two  points  have  to  be  taken  in  con- 
sideration. In  the  first  place  the  color  ;  this  green  color  is  one  of  the 
most  difficult  to  obtain  from  vegetables.  I  have  made  a  number  of 
experiments,  and  found  none  to  answer  so  well  as  the  green  coloring 
matter  precipitated  from  a  solution  of  indigo  by  lime. 
Another  point  is  the  disagreeable  odor  which  green  soap  usually  has, 
but  this  is  easily  overcome  by  a  few  drops  of  essential  oil,  for  instance, 
the  oil  of  citronella. 
The  following  formula  may  be  found  useful  in  preparing  this  soap  : 
Take  of  Oil  of  linseed,  U.  S.  P.,  . 
Solution  of  potassa,    .  .                   da  Oi 
Coloring  matter,  '  .              .              .  q.  s. 
Oil  of  citronella,        .  .              .      gtts.  x 
Place  the  oil  and  potassa  in  a  porcelain  dish ;  mix  thoroughly  and 
boil  with  a  regulated  heat  until  the  mass  becomes  thick  or  stringy  ; 
then  add  the  coloring  matter  and  the  oil  of  citronella,  with  constant 
stirring. 
If  the  oil  is  perfectly  saponified  the  mass  must  be  homogenous  and 
transparent ;  opaqueness  may  be  due  to  want  of  water,  or  to  an 
excess  of  fat,  or  of  solution  of  potassa.  The  first  and  the  last  can  be 
remedied  by  a  small  quantity  of  water,  and  if  the  proportion  of  oil 
was  too  large,  an  addition  of  solution  of  potassa  will  render  the  mix- 
ture clear. 
PRESCRIPTION  CLAMPS. 
Editor  American  Journal  of  Pharmacy  : 
I  have  read  with  interest,  in  the  October  number  of  the  Journal, 
the  article  by  Mr.  Andrew  Blair  on  the  dispensing  of  prescriptions. 
Permit  me  to  communicate  to  you  a  contrivance  which,  about  a  year 
ago,  I  published  in  the  "  Pharmaceutische  Zeitung,"  and  which,  I  am 
pleased  to  say,  seems  to  have  found  great  favor  in  Germany,  but  has 
been  probably  overlooked  by  you. 
My  little  apparatus  will  be  easily  understood  from  the  accompanying 
sketch.  These  prescription  clamps  (No.  i)  are  marked  with  a  large 
figure  and  if  not  in  use,  contain  a  check  with  the  same  figure  and  with 
