424 
ON  LACTIC  ACID. 
By  saturating  lactic  acid  with  hydrated  oxide  of  bismuth,  the 
author  obtained  a  basic  salt,  which  was  mixed  with  the  excess 
of  oxide  of  bismuth  added.  The  solution  filtered  therefrom, 
furnished  on  evaporation  the  monobasic  bismuth-salt,  Bi03-f 
C12  H9  O9. 
It  appears  therefore  on  the  whole  that  lactic  acid  may  take 
up  4  atoms  of  base,  although  these  tetrabasic  salts  are  not  easily 
obtained. 
By  the  action  of  perchloride  of  phosphorus  upon  lactic  acid, 
which  was  for  the  most  part  converted  into  anhydride  by  heating 
to  266°  F.,  the  author  did  not  obtain  any  simple  '  result. 
Gaseous  protochloride  of  methyle  was  evolved  without  any 
application  of  heat ;  on  heating  the  contents  the  retort  became 
black,  with  evolution  of  much  muriatic  acid  gas  and  oxide  of 
carbon.  The  residue  contained  phosphoric  acid  and  anhydride 
of  lactic  acid. 
In  the  lactic  fermentation,  as  is  well  known,  other  products, 
among  which  mannite  and  gum  occur  in  abundance,  are  formed, 
together  with  the  lactic  acid.  The  gum  detected  by  Kirchhof 
has  been  obtained  pure  by  the  author  in  the  following  way. 
The  aqueous  solution  of  lactic  acid  produced  in  the  process  is 
strained  away  from  the  residue,  the  lime  precipitated  by  sul- 
phuric acid,  and  the  aqueous  solution  by  alcohol.  The  precipi- 
tate is  repeatedly  dissolved  in  water  acidulated  with  muriatic 
acid,  and  purified  by  repeated  precipitation  by  alcohol.  When 
dried  at  200p  F.  and  analysed,  it  gave — 
c 
4444 
12 
43-61 
H 
6-17 
10 
6-25 
0 
49-39 
10 
5044 
The  gum  produced  in  the  fermentation  is  not  identical  either 
with  dextrine  or  arabine.  In  its  alkaline  solution  it  does  not 
reduce  peroxide  of  copper,  but  a  pale  blue  precipitate  is  formed 
which  does  not  change  its  color  by  boiling  ;  in  this  respect  it 
resembles  arabine.  On  the  other  hand,  the  aqueous  solution 
deviates  the  plane  of  polarization  to  the  right  like  dextrine.  No 
mucic  acid  is  produced  by  treatment  with  nitric  acid. — lbid} 
from  Liebigs  Annalen. 
