Am.  Jour.  Pharm.  | 
Aug.,  19 1 7.  J 
Current  Literature. 
385 
In  a  number  of  cases  animals  have  been  poisoned  by  salt  made 
from  the  brines  of  the  Ohio  River  valley  in  West  Virginia  and  Ohio. 
This  salt  has  been  found  to  contain  frequently  considerable  amounts 
of  barium  chlorid.  The  Bureau  of  Chemistry  has  fixed  a  maximum 
of  0.05  per  cent,  as  a  tentative  standard  for  food  salt.  In  practice, 
it  has  been  found  that  what  is  known  as  No.  1  grade  salt  may  contain 
from  0.02  to  0.23  per  cent,  of  barium,  and  the  barium  chlorid  con- 
tent of  Xo.  2  grade  may  vary  from  1.02  to  10.75  Per  cent-  The  No. 
2  grade  is  not  ordinarily  sold  for  table  or  dairy  purposes,  and  in 
recent  years  it  has  been  customary  to  label  it  "  Not  for  food  pur- 
poses," or  "  Do  not  feed  to  stock." 
This  naturally  interferes  with  the  demand  for  No.  2  salt  and 
there  is  a  great  temptation  for  the  manufacturer  to  dispose  of  it  by 
substituting  it  for  or  mixing  it  with  No.  1.  No.  1  grade  salt  is  the 
trade  name  for  the  product  that  first  crystallizes  out  when  the  brine 
is  evaporated  in  long,  shallow  tanks  or  grainers.  After  the  impurities 
in  the  brine  become  too  concentrated  as  a  result  of  this  process,  the 
brine  is  run  into  other  grainers  and  evaporation  continued.  The  salt 
from  the  second  grainers  is  called  No.  2,  or  off-grade  salt.  There  is 
no  definite  rule  for  determining  when  the  production  of  No.  1  salt 
should  cease  and  No.  2  begin,  and  there  is,  therefore,  a  temptation 
for  the  salt  manufacturer  to  continue  evaporation  in  the  first  grainers 
longer  than  the  concentration  of  impurities  in  the  brine  warrants. 
The  new  method  of  getting  rid  of  barium  remedies  this  to  a  great 
extent  by  permitting  a  greater  production  of  what  can  be  truly  called 
No.  1  grade  salt.  It  also  aids  in  the  elimination  from  the  market  of 
salt  that  may  be  a  dangerous  product. 
This  method  calls  for  the  addition  of  a  solution  of  salt  cake 
(sodium  sulphate),  the  acidity  of  which  has  been  neutralized  with  a 
small  amount  of  lime,  to  the  brine  in  large  settling  tanks.  Air  is 
blown  through  in  order  to  stir  thoroughly  the  mixture  and  to  decom- 
pose the  bicarbonate  of  iron  naturally  present.  This  forms  a  flock 
and  produces  a  rapid  sedimentation  of  the  insoluble  barium  sulphate 
formed.  The  cost  of  the  treatment  is  estimated  at  about  1  cent  per 
barrel  of  salt,  which  is  more  than  offset  by  the  increased  value  of 
the  product.  In  one  large  salt  factory  this  process  has  been  in 
operation  for  over  a  year,  and  it  has  been  found  that  only  insignifi- 
cant traces  of  barium  remain  in  the  No.  2  salt  which  is,  therefore,  a 
safe  product  for  food  purposes. 
