Am.  Jour.  Pharm.  ") 
Dec.  1, 1871.  j 
Note  on  Pure  Carbolic  Acid. 
549 
The  carbolic  acid  from  the  same  source  has  certain  advantages  ovei" 
the  coal-tar  acid,  consequent  upon  its  extreme  purity.  It  is  less  deli- 
quescent, and  cannot  possibly  be  open  to  the  suspicion  of  contamina- 
tion with  certain  other  products  of  coal-tar  which  possess  injurious 
qualities.  This  occasional  suspicion,  indeed,  has  led  to  the  introduc- 
tion of  the  costly  thymol  in  France,  as  a  substitute,  in  delicate  cases, 
for  carbolic  acid. 
In  conclusion,  I  am  led  to  the  belief  that  it  would  not  be  advisable 
to  prepare  carbolic  acid  from  this  singular  source,  when  the  compara- 
tive cost  shows  that  the  gain  must  be  very  small  or  non-existent.  But 
it  appears  to  me  well  worthy  of  record  that,  should  circumstances 
render  the  supply  of  the  English  product  difficult  or  uncertain,  as  in 
the  case  of  war,  or  the  English  price  increase,  a  practically  inexhaust- 
ible source  exists  in  this  country  from  which  this  indispensable  sub- 
stance, in  its  purest  state,  can  be  obtained  at  a  slight  enhancement  of 
the  present  price. — Pharm.  Journ.^  Lond.^  Oct.  7,  1871. 
NOTE  ON  PURE  CARBOLIC  ACID. 
By  Professor  Church,  M.A. 
Since  1856  I  have  occupied  myself  a  good  deal  with  experiments 
as  to  the  practical  hygienic  applications  of  carbolic  acid,  particularly 
as  to  its  use  in  dentistry  and  in  throat  affections,  and  also  as  regards 
its  employment  as  a  disinfectant.  The  rank  of  carbolic  acid  as  a 
most  valuable  contribution  from  chemistry  to  medicine  is  so  well  as- 
sured that  it  is  unnecessary  to  insist  upon  this  point  here.  Yet  there 
is  an  objection  urged  against  this  substance,  which  has  some  appa- 
rent force,  simply  because  the  best  preparations  of  commerce  are  so 
seldom  free  from  a  gas-like  or  naphthalic  odor,  which,  though  entirely 
foreign  to  carbolic  acid  itself,  has  condemned  its  use  in  some  quarters. 
About  11  years  ago,  in  preparing  pure  carbolic  acid  for  the  use  of  a 
surgeon-dentist  to  whom  I  introduced  it,  I  adopted  a  plan  which  I 
shortly  afterwards  described  before  the  Odontological  Society,  and  to 
which  I  have  been  lately  asked  to  give  greater  publicity.  My  plan, 
which  is  very  simple,  is  as  follows  : — 
One  pound  of  the  best  carbolic  acid  of  commerce  (I  use  Calvert's 
white  crystallized  acid)  is  poured  into  20  pounds  of  cold  distilled 
water,  taking  care  not  to  permit  the  whole  of  the  acid  to  enter  into 
