250  Gleanings  from  the  German  Journals.  { Am,MTay''i8 ^rm~ 
and  can  be  volatilized  without  leaving  a  residue. — Ber.  d.  Deutsche 
Chem.  Ges.,  1879,  p.  11. 
Benzoate  of  Sodium. — The  commercial  salt  is  usually  amorphous,, 
has  a  strong,  unpleasant  odor,  a  strongly  alkaline  reaction,  and  frequently 
contains  considerable  sodium  chloride  and  sulphate.  Bernbeck  prepares* 
the  pure  compound  by  treating  pure  diluted  soda  lye  with  pure  benzoic 
acid  until  slightly  acid,  heating  moderately,  filtering,  and,  if  intended 
to  be  dispensed  in  a  liquid  form,  bringing  to  the  specific  gravity  of  1*04. 
at  20°C,  when  the  solution  contains  10  per  cent,  of  the  dry  salt.  The 
crystals  are  obtained  by  evaporating  the  solution  on  a  sand  bath  at  a 
temperature  of  about  6o°C.  to  one  half,  and  placing  the  residue  over 
sulphuric  acid,  when  crystals  will  form.  O.  Schlickum  triturates 
6  parts  of  benzoic  acid  with  7  parts  of  crystallized  sodium  carbonate 
in  a  porcelain  mortar  with  pressure,  when  carbonic  acid  soon  begins  to 
escape  and  the  mixture  becomes  soft;  this  is  dissolved  in  water,  a  little 
alcohol  is  added  and  the  mixture  dried  in  the  air,  when  8  parts  of  ben- 
zoate of  sodium  are  obtained;  if  dried  at  ioo°,  7  parts  of  anhydrous 
salt  remain. 
Benzoate  of  Magnesium. — 12  parts  of  benzoic  acid  and  5  to  6  parts 
of  magnesium  carbonate,  dissolved  in  luke-warm  water,  yield  18*5  parts 
benzoate  of  magnesium.  In  order  to  obtain  a  neutral  salt  calcined 
magnesia  is  added  after  the  addition  of  5  parts  of  the  carbonate,  until 
blue  litmus  paper  is  no  longer  reddened.  The  liquid  is  then  filtered,, 
evaporated  and  placed  in  a  cool  place,  when  needles  having  the  con- 
stitution Mg2C7H602-f-6H20  are  obtained. — Pharm.  Ztg.,  Feb.  19 
and  March  5,  1879. 
Starch  in  Milk. — Dr.  Vulpius  coagulates  the  suspected  milk,  pre- 
viously heated  to  the  boiling  point,  with  a  few  drops  of  acetic  acid,  and 
filters  after  cooling,  when  the  addition  of  a  single  drop  of  a  saturated 
aqueous  solution  of  iodine,  containing  0*2  gr.  iodine  in  a  liter,  will 
cause  a  blue  cloud,  disappearing  on  shaking;  the  coloration  remains 
for  one  minute  if  1  cc.  is  added  to  5  cc.  of  the  filtered  serum,  and 
constant,  if  another  cc.  is  added.  The  presence  of  5  milligrams  of 
starch  in  5  cc.  milk  can  thus  be  easily  determined  by  the  addition  of 
milligram  iodine. — Pharm.  Ztg.y  March  5,  1879. 
Determination  of  Carb:>lic-Acid-Intoxication. —  Normal  urine 
contains  sulphates,  yielding  a  precipitate  with  barium  chloride,  insoluble 
