18  PREPARATION  OF  CARBOLIC  (PHENIC)  ACID. 
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entirely  dissolved  to  a  clear  solution.  The  complete  absence 
of  prussic  acid  was  thus  proved.  All  of  it  had  been  com- 
pletely removed.  ^ 
We  prepared  as  above  another  quantity  of  magnesia  emul- 
sion mixed  with  prussic  acid,  and,  after  adding  the  iron  solu- 
tion, the  liquid,  having  been  filtered  from  the  mixture,  was 
without  delay  distilled,  and  on  testing  the  distillate,  it  neither 
answered  to  the  Prussian  blue  nor  to  the  silver  test ;  it  con- 
tained no  prussic  acid. 
We  believe  ourselves  justified  in  now  giving,  as  the  antidote 
for  prussic  acid,  magnesia  and  a  proto-persalt  of  iron,  thus: — . 
Make  into  a  smooth  cream,  with  water,  from  1  to  2  drachms  of 
calcined  magnesia.  Give  the  emulsion  to  the  patient,  then 
give,  in  water,  a  solution  of  16  minims  of  perchloride  of  iron, 
and  12 J  grains  of  green  vitriol.  These  numbers,  being  in 
excess  of  the  theoretical  quantity,  were  those  used  in  our  ex- 
periments. Should  it  be  supposed  that  so  much  as  400  minims 
of  medicinal  prussic  acid  had  been  taken,  of  course  four  times 
the  quantity  of  the  iron  compound  necessary  for  100  minims 
should  be  given,  but  without  altering  the  quantity  of  magnesia. 
Although  calcined  magnesia,  alone,  slowly  dissolves  in  prus- 
sic acid,  yet  in  the  presence,  simultaneously,  of  a  large  excess 
of  magnesia  and  the  solution  of  a  proto-persalt  of  iron,  the 
reciprocal  action  resulting  in  the  formation  of  a  Prussian  blue, 
seems  to  be  almost  instantaneous. — London  Pharm.  Journal, 
Nov.  1,  1865. 
PREPARATION  OF  CARBOLIC  (PHENIC)  ACID. 
By  M.  Muller. 
Phenic  acid  or  phenilic  alcohol  is  usually  accompanied  by  its 
congeners,  xylic  and  cressylic  alcohols,  which  adL  re  to  it  with 
gieat  tennacity,  and  give  it  the  property  of  becoming  brown  in 
contact  with  the  air.  For  its  purification  the  author  has  re- 
course to  a  partial  neutralization,  and  afterwards  to  the  fractional 
distillation  of  the  product. 
The  crude  tar  cedes  to  soda  or  lime  water  a  mixture  of  the 
matters  before  mentioned,  as  well  as  naphthaline,  wfcich  is  solu- 
