PREPARATION  OF  SUCCINIC  ACID  FROM  MALATB  OP  LIME.  355 
That  an  incomplete  change  with  formation  of  lactic  acid,  and 
secondarily  of  bodies  produced  from  this,  is  caused  by  the  pre- 
sence of  sugar  in  the  malate  of  lime,  is  proved  by  the  circumstance, 
that  when  grape-sugar  is  added  to  pure  malate  of  lime  before  the 
fermentatiou,  the  result  is  lactate  of  lime,  and  when  the  action 
of  the  ferment  is  continued  longer,  it  is  principally  metacetonate 
of  lime,  &c.  According  to  this,  it  is  in  the  power  of  the  experi- 
menter to  produce  one  or  other  of  these  bodies  at  pleasure.  The 
extremely  bad  odor  of  the  most  putrid  caseine  already  mentioned, 
soon  gives  place  to  that  of  lactic  acid  when  sugar  is  present,  and 
is  not  again  perceptible  if  the  latter  be  in  sufficient  quantity.  The 
base  with  which  the  lactic  acid  first  combines  is  the  ammonia  pro- 
duced from  the  caseine. 
The  caseine,  which  serves  as  a  ferment  in  this  process,  is  pre- 
pared as  above  described.  It  is  frequently  kneaded,  until  at  last 
it  forms  a  brownish,  perfectly  homogeneous  mass,  of  not  the 
most  pleasant  odor.  This  mass  exhales  considerable  quantities 
of  ammonia.  If  caseine  in  the  above  condition  be  mixed  with 
sulphuric  acid,  a  slight  odor  of  butyric  and  acetic  acids  is 
evolved  on  the  application  of  heat ;  whilst  that  of  metacetonic 
acid  is  very  distinctly  perceptible.  It  is  clear  that  these  acids 
are  combined  with  ammonia  in  the  putrid  caseine,  as  solution  of 
potash,  especially  when  hot,  sets  free  a  considerable  quantity  of 
ammonia.  When  the  caseine  has  acquired  the  above  properties, 
and  the  fermentation  of  the  malate  of  lime  has  been  effected 
under  the  above  conditions,  the  desired  product,  succinate  of 
lime,  is  obtained,  together  with  the  collateral  products  already 
mentioned.  The  metacetonic,  butyric,  and  acetic  acids  present 
in  the  caseine,  combined  with  ammonia,  are  evidently  the  last 
members  of  the  series  of  lactic  acid  formed  from  sugar  of  milk. 
The  decomposition  of  the  former  into  butyric  and  acetic  acids 
by  the  further  action  of  the  ferment  is  extremely  probable ;  and 
the  author  proposes  to  investigate  these  matters  more  closely. 
Quite  a  different  result  is  obtained  in  the  fermentation  of 
malate  of  lime  when  fresh  caseine  is  employed.  This  still  con- 
tains sugar  of  milk,  and  the  lactic  acid  formed  from  it.  Half- 
way between  the  fresh  and  putrid  caseine  stands  that  which  is 
employed  in  domestic  economy  in  the  manufacture  of  cheese. 
This  combines  the  properties  of  both.    According  to  the  degree 
