460 
Current  Literature. 
Am.  Jour.  Pharm. 
June,  1918. 
washed  twice  with  hot  water.  To  the  filtrate  is  then  added  N/I 
sulphuric  acid  equal  in  volume  to  the  quantity  of  N/I  potassium 
hydroxide  solution,  together  with  an  amount  equivalent  to  the  dif- 
ference between  the  total  alkalinity  of  the  ash  expressed  as  potassium 
bitartrate  corresponding  with  the  amount  of  total  tartaric  acid  in 
the  wine.  The  solution  is  now  evaporated  to  a  syrup,  water  is 
added,  and  the  evaporation  repeated  so  as  to  expel  all  volatile  acids. 
The  residue  is  treated  with  a  few  drops  of  water,  2  Grms.  of  animal 
charcoal,  and  a  quantity  of  sand ;  25  Cc.  of  95  per  cent,  alcohol  are 
added,  and  the  mixture  is  extracted  with  50  Cc.  of  ether.  After  the 
ethereal  solution  has  been  decanted  through  a  filter,  the  extraction 
is  continued  with  successive  quantities  of  15  Cc.  of  a  mixture  of 
equal  volumes  of  alcohol  and  ether.  The  extract  is  then  evaporated 
to  about  5  Cc,  0.2  Grm.  of  animal  charcoal  and  10  Cc.  of  water  are 
added,  the  mixture  is  filtered,  and  the  precipitate  washed  with  a 
small  quantity  of  hot  water.  The  filtrate  is  concentrated,  neutral- 
ized, while  boiling,  with  alkali  (calcium  hydroxide)  solution,  again 
evaporated  to  about  8  Cc,  and  treated  with  one  drop  of  50  per  cent, 
acetic  acid  and  90  Cc.  of  warm  95  per  cent,  alcohol.  The  mixture 
is  heated  to  boiling,  filtered,  and  the  precipitate  of  calcium  malate 
and  succinate  washed  with  85  per  cent,  alcohol.  An  estimation  of 
calcium  in  the  filtrate  gives  the  corresponding  quantity  of  lactic  acid. 
The  precipitate  is  then  dissolved  in  boiling  water  (a  small  quantity 
of  calcium  phosphate  may  remain  insoluble),  the  solution  is  evapo- 
rated to  8  Cc,  1  Cc.  of  glacial  acetic  acid  and  90  Cc.  of  95  per  cent, 
alcohol  are  added,  the  mixture  is  boiled,  and  the  precipitated  cal- 
cium malate  collected  on  a  filter  and  washed  with  warm  85  per  cent, 
alcohol  containing  a  trace  of  acetic  acid.  The  quantities  of  calcium 
in  the  precipitate  and  filtrate  give  the  amounts  of  malic  and  suc- 
cinic acids  respectively.  Citric  acid,  if  present  in  the  wine,  is  pre- 
cipitated with  the  calcium  malate.  In  the  case  of  sweet  wines,  the 
wine  after  neutralization,  removal  of  tannins,  and  treatment  with 
sulphuric  acid,  is  evaporated  to  a  syrup,  and  the  latter  is  extracted 
several  times  with  a  mixture  of  20  Cc.  of  alcohol  and  50  Cc.  of 
ether.  The  extract  is  then  evaporated  and  treated  as  described.  In 
normal  wines,  the  succinic  acid  content  is  usually  about  0.70  Grm. 
per  liter ;  the  quantities  of  lactic  and  malic  acids  vary  considerably 
according  to  the  origin  and  nature  of  the  wine.  (J.  Laborde; 
Comptes  rend.,  191 7,  165,  793-795.    From  The  Analyst.) 
