Am.  Jour.  Pharm.) 
March,  1894.  / 
Crude  Carbolic  Acid. 
117 
finally  remains  in  the  barrels  as  an  oily  mass,  which  will  not  again 
become  liquid,  thereby  occasioning  a  serious  loss  to  the  purchasers. 
It  does  not  appear  to  be  generally  understood  that  these  acids  con- 
sist largely  of  oil,  for  it  is  a  common  occurrence  to  find  disinfecting 
acids  in  bottles,  labelled  with  directions  for  mixing  with  water,  when 
a  test  shows  that  it  is  entirely  insoluble  in  water,  and  contains  only 
a  small  percentage  of  acid. 
Many  methods  of  testing  crude  carbolic  acids  have  been  proposed, 
which  apparently  ignore  the  large  per  cent,  of  oil  present. 
An  instance  of  this  is  the  method  recently  proposed  by  Seiler, 
and  which  has  been  extensively  copied  by  journals  throughout  the 
country. 
His  method  is  to  weigh  100  grams  of  the  sample  in  a  large 
beaker,  adding  milk  of  lime  (obtained  by  slaking  200  grams  of  lime) 
and  diluting  to  one  liter.  The  whole  is  placed  on  a  water-bath  and 
stirred  for  an  hour,  after  which  the  same  amount  of  water  is  again 
added,  when  cold  it  is  filtered,  washed  with  fresh  water  and  filtered 
again.  The  acid  is  liberated  by  hydrochloric  acid,  salt  being  added 
to  the  solution  to  remove  as  far  as  possible  the  acid  dissolved  in 
the  liquor.  It  is  then  separated  and  weighed.  He  sums  up  the 
result  of  his  investigation  by  stating  that  an  acid  sold  as  25-30  per 
cent,  showed  only  2  to  3  per  cent.;  a  40-60  per  cent,  acid  gave  3  to 
5  per  cent.;  a  50-80  per  cent,  and  a  90-100  per  cent.,  80  per  cent. 
From  this  he  concludes  that  commercial  acids  contain  considerably 
less  than  stated,  and  that  the  lower  grades  are  worthless. 
To  one  acquainted  with  the  nature  of  crude  carbolic  acids,  the 
defects  of  this  method  are  at  once  apparent.  The  slaked  lime  on 
mixing  with  the  acid  forms  an  oily  mass,  from  which  it  is  nearly 
impossible  to  extract  any  acid.  Lime  is  too  weak  a  base  to  extract 
the  last  portions  of  acid  from  the  oil,  and  the  voluminous  liquid, 
amounting  with  the  wash  waters  to  about  three  liters,  dissolves  a 
large  percentage  of  the  acid  even  when  saturated  with  salt. 
It  will  be  noted  that  the  crude  acid  said  to  contain  the  larger 
amounts,  gave  better  figures  than  the  low  grades,  which  was  to  be 
expected,  as  there  was  about  the  same  amount  dissolved  in  the  salt 
solution  from  that  acid  that  should  have  given  25  cc.  of  acids,  as 
from  that  which  should  give  ICO  cc. 
As  these  crude  acids  are  only  for  disinfecting  purposes,  and  as 
cresylic  and  the  higher  acids  are  now  recognized  to  have  the  same, 
