242  Gleanings  from  the  Foreign  Journals,  {A%£^i87h7?rm 
as  having  been  designed  by  me  ;  but,  to  guard  against  any  possible 
imputation,  and  knowing  as  I  do  that  the  manufacturing  and  wholesale 
drug  houses  of  this  city  compare  favorably  in  character  and  integrity  with 
those  of  any  other  city  of  our  country,  I  would  request  you  to  bring 
this  explanation  to  the  notice  of  your  readers,  and  oblige 
Yours,  etc.,  Rich.  V.  Mattison. 
GLEANINGS  FROM  THE  FOREIGN  JOURNALS. 
By  the  Editor. 
Detection  of  Free  Mineral  Acid  in  Vinegar. — Vinegar  alwavs* 
contains  organic  salts  of  the  alkalies,  which  on  evaporation  and  incin- 
eration are  converted  into  carbonates.  By  the  addition  to  the  vinegar 
of  a  mineral  acid  in  sufficient  quantity,  these  salts  are  decomposed,  and 
on  evaporation  and  ignition  the  ash  left  will  have  a  neutral  instead  of 
an  alkaline  reaction.  Based  upon  these  considerations,  the  following 
method  for  the  estimation  of  free  mineral  acid  has  been  devised  by 
Otto  Hehner  :  50  cc.  of  the  vinegar  are  mixed  with  25  cc.  of  deci- 
normal  soda  solution,  or  with  a  sufficient  quantity  so  that  on  evapora- 
tion and  incineration  an  ash  having  an  alkaline  reaction  is  left  ;  the 
residue  is  dissolved  in  decinormal  sulphuric  acid  corresponding  to  the 
soda  solution,  boiled  to  expel  carbonic  acid,  filtered,  the  filter  washed 
with  water,  the  liquid  reddened  by  litmus  and  neutralized  by  decinor- 
mal soda  solution,  the  volume  of  which  indicates  directly  the  propor- 
tion of  free  mineral  acid  present,  100  cc.  of  the  standard  solution  cor- 
responding to  o*49  gram  of  H2S04. 
The  same  process  is  likewise  applicable  fcr  the  determination  of  free 
mineral  acid  in  lime-  and  lemon-juice. — Phar.  Jour,  and  Trans.,  Nov. 
11,  1876,  from  the  Analyst. 
Purification  and  Uses  of  Petroleum. — M.  Masson,  pharmacies 
of  Lyons,  has  succeeded  in  removing  the  disagreeable  odor  of  petro- 
leum by  the  following  process:  Into  a  vessel  containing  100  kilos  of 
petroleum  are  separately  introduced,  by  means  of  a  long  funnel,  60 
grams  each  of  sulphuric  and  nitric  acid,  and  500  grams  of  stronger 
alcohol  are  carefully  poured  upon  the  surface  of  the  petroleum.  The 
alcohol  gradually  sinks  to  the  bottom,  and  when  coming  into  contact 
with  the  acids  heat  is  developed  and  some  effervescence  takes  place,, 
but  not  in  proportion  to  the  quantity  of  the  liquids.    Etherial  products 
