550 
Note  on  Pure  Carbolic  Acid. 
(  Am,  Jour.  Phaem. 
t     Dec.  1, 1871. 
solution.  With  a  good  sample,  if  after  shaking  repeatedly  at  in- 
tervals, between  two  and  three  ounces  of  the  acid  remain  at  the  bot- 
tom of  the  vessel  used,  this  will  be  a  sufficient  residue  to  hold  and 
contain  all  the  impurities.  With  bad  samples,  less  water  must  be 
used  or  more  acid.  The  aqueous  solution  should  be  syphoned  off, 
and  filtered  if  necessary  through  Swedish  paper  till  perfectly  clear  ; 
it  is  then  placed  in  a  tall  cylinder,  and  pure  powdered  common  salt 
added  with  constant  agitation  till  it  no  longer  dissolves.  On  stand- 
ing, the  greater  part  of  the  carbolic  acid  will  be  found  floating  as  a 
yellow  oily  layer  on  the  top  of  the  saline  liquor,  and  merely  requires 
to  be  removed  by  a  syphon  or  pipette  to  be  ready  for  use.  As  it 
contains  5  per  cent,  or  more  of  water,  it  does  not  generally  crystal- 
lize, but  it  may  be  made  to  do  so  by  removing  it  to  a  retort,  and  dis- 
tilling it  from  a  little  lime.  The  portion  collected  up  to  185°C.  or 
thereabouts  has  at  ordinary  temperatures  scarcely  any  odor,  save  a 
faint  one  resembling  that  of  geranium  leaves  ;  and  I  have  taken  ad- 
vantage of  this  curious  resemblance  still  further  to  mask  the  slight 
smell  proper  to  absolutely  pure  carbolic  acid  by  the  addition  to  it  of 
four  drops  per  fluid  ounce  of  the  French  oil  of  geranium.  This  addi- 
tion has  the  further  advantage  of  liquefying  the  pure  crystallized 
product. 
The  carbolic  purified  as  above  has  been  so  highly  appreciated  by 
those  professional  and  private  persons  to  whom  I  have  distributed 
samples,  and  who  were  dissatisfied  with  the  purest  commercial  sam- 
ples, that  I  have  thought  it  best  to  publish  my  simple  plan,  for 
which,  however,  I  claim  no  originality.  It  involves,  I  know,  consid- 
erable loss  of  material,  but  the  saline  liquor  remaining  may  be  dis- 
tilled and  thus  made  to  yield  up  a  second  portion  of  pure  carbolic 
acid,  and  it  will  be  found  a  very  pleasant  and  effective  domestic  disin- 
fectant and  deodoriser. 
When  dissolved  in  230  parts  of  water  and  used  as  a  gargle,  or  in 
25  parts  for  painting  the  throat,  or  in  50  parts  for  a  carbolic  spray, 
the  pure  acid  is  rarely,  if  ever,  objected  to  even  by  the  most  fastidi- 
ous person.  Of  course  it  may  be  readily  mingled  with  olive  or  other 
oil  (1  :  25);or  with  glycerine,  for  dressing  cuts  and  sores,  and  when 
introduced  into  the  little  air-purifier  invented  by  me  and  noticed  in 
your  columns  some  months  back,  diffuses  wholesome  and  inoffensive 
vapor  in  any  place  where  there  are  disagreeable  effluvia  of  vegetable 
or  animal  origin. —  Chemical  News,  October  13,  1871. 
