Ase^H;f873RM*}  Lactic  Acid.  389 
though  in  appearance  quite  unimpeachable,  yet  does  not  fulfil  all  the 
requirements  which  are  demanded  by  critical  pharmacy. 
Our  market  is  supplied  with  lactic  acid  from  Europe,  chiefly,  if  not 
exclusively,  from  Germany ;  although  attempts  have  been  made  to 
manufacture  it  in  this  country,  yet  the  greater  outlay  for  material, 
wages,  etc.,  has  made  it  impossible  for  our  manufacturers  to  com- 
pete with  those  abroad.  Being  therefore  dependent  upon  foreign 
makers,  it  becomes  so  much  more  our  duty  to  watch  its  quality,  and 
to  reject  any  which  does  not  come  up  to  the  standard  fixed  by  our 
Pharmacopoeia. 
Some  time  ago,  while  engaged  in  converting  some  lactic  into  oxalic 
acid  by  means  of  nitric  acid,  I  noticed,  after  neutralization  of  the 
solution  with  ammonia,  a  small  quantity  of  a  white  precipitate,  which 
was  found,  on  examination,  to  be  oxalate  of  lime  ;  and  on  examining 
the  remainder  of  the  same  lactic  acid,  the  presence  of  lime  was  un- 
mistakably established.  Unfortunately,  the  bottle  had  been  deprived 
of  its  original  label,  so  that  its  source  could  not  with  certainty  be 
determined,  but  the  result  arrived  at  led  me  to  reserve  a  few  sam- 
ples of  different  lots,  in  order  to  ascertain  their  purity  and  compara- 
tive strength. 
Before  stating  the  results  of  my  investigation,  I  wish  to  give,  side 
by  side,  the  definition  and  remarks  of  the  United  States  and  German 
Pharmacopoeias  : 
U.  S.  Pharmacopoeia.  l  German  Pharmacopoeia. 
A  syrupy,  nearly  transparent  liquid,  ■  A  syrupy,  colorless  or  yellowish,  odor- 
of  a  pale  wine  color,  having  a  slight  less  and  acid  liquid,  of  the  sp.  gr.  1*24. 
bland  odor  and  a  very  sour  taste.  Its  j  Is  charred  at  a  strong  heat,  burns  with 
sp.  gr.  is  1-212.  I  a  bright  flame,  and  is  volatile  without 
residue. 
It  unites  in  all  proportions  with  water,  j  Soluble  in  water,  alcohol  and  also  m 
alcohol  and  ether.  |  ether. 
Mixed  with  solution  of  permanganate 
of  potassium,  and  gently  heated,  it  dif- 
fuses the  odor  of  aldehyde. 
When  diluted  with  water,  it  is  not 
made  turbid  by  chloride  of  barium,  ox- 
alate of  ammonium,  nitrate  of  silver  or 
hydrosulphuric  acid  solution. 
It  is  not  precipitated  by  solution  of 
acetate  of  lead  or  of  oxalate  of  ammo- 
nium, and  when  neutralized  with  am- 
monia, affords  no  precipitate  with  hy- 
drosulphuric acid. 
When  gently  heated,  it  yields  no  odor 
of  acetic  or  butyric  acids.  90  grains 
of  lactic  acid  are  neutralized  by  not 
less  than  75  grains  of  bicarbonate  of 
potassium.  When  treated  with  a  caus- 
tic alkali  in  excess,  the  color  is  not 
materially  deepened. 
When  gentlyheated.it  should  yield 
no  odor  of  acetic  or  butyric  acids. 
