EE  MARKS  ON  FLAVORING  EXTRACTS. 
215 
tion  of  sulphate  of  magnesia  ;  after  frequent  agitation  filter, 
transfer  to  a  porcelain  capsule,  and  boil  quickly  till  reduced  to  a 
small  bulk  ;  collect  the  precipitate  on  a  filter,  wash  thoroughly, 
and  when  nearly  dry,  transfer  to  a  crucible  free  from  iron  and 
calcine,  bearing  in  mind  the  suggestion  of  Mr.  Barr,  "  that  a 
low  heat  just  approaching  to  redness  and  long  continued,  will  en- 
sure a  much  finer  product  than  a  high  heat  for  a  short  time  ;" 
which  also  corresponds  with  my  experience,  some  specimens  being 
completely  ruined  by  neglecting  this  precaution. 
The  magnesia  thus  prepared  is  very  soft  and  velvety,  of  a  dead 
white  color,  and  a  specific  gravity  of  3.50,  or  rather  heavier,  pro- 
bably from  being  made  in  small  quantity,  thereby  ensuring  more 
care  than  would  be  possible  if  larger  quantities  were  made. 
The  rationale  of  this  process  is  the  following  :  The  addition 
of  NO5  to  the  solution  of  sulphate  of  magnesia  peroxidizes  the 
iron  present,  if  any,  and  the  subsequent  ebullition  after  precipi- 
tating a  little  carbonate  of  magnesia  by  the  addition  of  the  car- 
bonate of  soda  precipitates  the  ferruginous  oxide. 
When  cold  solutions  of  bi-carbonate  of  soda  and  sulphate  of 
magnesia  are  mixed,  no  precipitation  occurs  ;  but  when  the  mix- 
ture is  boiled,  carbonic  acid  is  given  off,  and  carbonate  of  magne- 
sia of  a  very  dense  texture  settles  to  the  bottom,  different  in  its 
character  from  that  which  is  formed  by  mixing  hot  solutions  of 
the  sulphate  and  carbonate.  When  the  carbonate  in  this  dense 
form,  is  calcined  at  the  low  heat  mentioned  above,  the  product 
lias  the  great  density  and  the  smoothness  so  desirable. 
Philadelphia,  April,  1856. 
KE MARKS  ON  FLAVORING  EXTRACTS. 
By  the  Editor. 
A  correspondent  having  requested  information  relative  to  the 
recipes  for  making  several  flavoring  extracts  suitable  for  culi- 
nary use,  we  have  deemed  it  not  out  of  place  to  present  such 
of  them  as  are  in  our  possession  to  the  readers  of  the  Journal, 
some  of  whom  may  find  them  available. 
Extract  of  Lemon. 
Take  of  the  Outer  yellow  rind  of  the  lemon     2  oz. 
Alcohol  95°  .(At wood's  deodorized)  1  pint 
Pure  oil  of  lemons  2  fluid  oz. 
