50  CONTAMINATION  OF  HYDROCHLORIC  WITH  SULPHURIC  ACID. 
filter,  evaporate  at  160°  F.  to  six  fluidounces,  add  the  balance 
of  the  sugar,  and  when  nearly  cool  pour  into  a  bottle  containing 
the  orange-flower  water,  and  make  up  with  water  if  necessary  to 
the  bulk  of  one  pint. 
This  syrup  has  a  dark  transparent  appearance,  with  a  decided 
odor  and  taste  of  the  lactucarium,  though  partly  covered  by  the 
orange-flower  water,  which  it  is  thought  is  a  good  addition.  In 
order  that  it  may  be  examined  by  those  present,  I  have  two 
samples  of  the  syrup  in  which  the  orange-flower  water  is  re- 
placed by  water. 
In  the  March  number  of  the  American  Journal  of  Pharmacy 
for  1868,  pp.  113  and  114,  are  two  papers  on  the  subject  of 
syrup  of  lactucarium.  Samples  of  the  syrups  by  both  processes 
are  herewith  presented. 
— Proc,  Amer,  Pliarm.  Assoc. ^  1868. 
ON  THE  CONTAMINATION  OF  HYDROCHLORIC  WITH  SUL- 
PHURIC ACID  AND  OTHER  OXIDES  OF  SULPHUR. 
By  Dr.  E.  R.  Squibb. 
Query  31. — Does  the  addition  of  metallic  iron  or  zinc  to  ordinary  hy- 
drochloric acid,  which  contains  sulphuric  acid  as  an  impurity,  decompose 
the  sulphuric  acid  and  liberate  sulphide  of  hydrogen  ? 
In  a  discussion  of  the  subject  of  tincture  of  the  chloride  of 
iron,  imperfectly  reported  at  page  97  of  the  Proceedings  of  last 
year,  the  writer  stated,  as  an  observed  fact,  that  the  escape  of 
sulphide  of  hydrogen  upon  dissolving  iron  or  zinc  in  hydrochloric 
acid  was  an  indication  of  the  presence  of  sulphuric  acid  as  a  con- 
tamination of  the  hydrochloric  acid,  and  was  a  good  practical 
test  for  detecting  sulphuric  acid.  Mr.  Maisch  spoke  doubtfully 
upon  the  accuracy  of  the  statement,  and  in  a  subsequent  conver- 
sation expressed  a  decided  conviction  that  it  could  not  be  true. 
The  writer  had  seen  the  proposed  reaction  so  often  that  he  had 
had  no  doubt  upon  the  subject  previous  to  Mr.  Maisch's  remarks, 
and  then  proposed  to  try  the  point  by  direct  investigation.  With 
this  end  in  view  the  writer  proposed  the  question  as  one  to  be 
reported  on  this  year,  and  accepted  the  investigation  for  himself. 
The  investigation  has  been  carefully  made,  and  proves  that  the 
escape  of  sulphuretted  hydrogen  during  the  reaction  in  question 
