"^'"jiiy'iSs''™'}        ^^'^'^  Wine,  Argols  and  Tartaric  Acid.  327 
cultivation,  yielding  11,678,545  pounds  of  grapes,  from  which  884,- 
895  gallons  of  wine  was  made.  In  1882,  18,526,219  pounds  were 
grown  and  1,296,295  gallons  of  wine  made. 
I  obtained  from  one  of  the  largest  wine  growers  in  the  State  a  sample 
of  the  argols  from  Catawba  (white)  wine  and  one  from  Concord  (red) 
wine,  which  were  estimated  for  the  percentage  of  tartaric  acid  by  the 
scheme  given  in  Allen's  Commercial  Organic  Analysis."  This  con- 
sists of  digesting  an  amount  of  the  sample  in  powder,  supposed  to  con- 
tain about  2  grammes  of  tartaric  acid,  wdth  water  until  thoroughly 
softened.  A  strong  solution  of  neutral  potassium  oxalate  is  next  added 
in  sufficient  quantity  to  react  with  all  the  calcium  salt  present  and 
leave  an  excess  of  about  1"5  gm.  of  the  salt,  and  the  mixture  is  heated, 
w^ith  frequent  stirring,  for  some  time.  The  solution,  which  generally  is 
strongly  acid,  is  carefully  neutralized  with  solution  of  potash.  After 
a  little  further  heating  the  liquid — which  should  not  occupy  more  than 
40  cc. — is  filtered  on  a  small  filter,  the  residue  well  washed  and  the 
washings  concentrated  and  added  to  the  main  solution  which  is  made 
up  to  about  50  cc.  A  strong  solution  of  about  2  gm.  of  citric  acid  is 
added,  the  liquid  being  well  stirred.  After  twelve  hours  tlie  precipitate 
is  collected  and  washed  with  a  saturated  solution  of  acid  potassium 
tartrate,  containing  about  five  per  cent,  of  potassium  chloride.  The 
filter  and  contents  are  removed  to  a  beaker  dissolved  in  hot  water  and 
treated  with  standard  alkali.  Each  cc.  of  normal  alkali  equals  "150 
gm.  of  tartaric  acid. 
Three  estimations  of  the  red  wine  argols  gave  51*57,  53*57  and 
52*8  per  cent.,  an  average  of  52-65  per  cent.  Three  estimations  of 
those  of  the  white  wine  gave  69',  66*3  and  70*2  percent.,  an  average  of 
68*5  per  cent.  The  white  argols  give  27*53  per  cent,  of  ash  and  the 
red  argols  16*43  per  cent.  The  precipitate  with  potassijim  oxalate  in 
the  percentage  estim.ation  of  the  white  argols  gives  20*4  per  cent,  of 
ash,  the  red  w^ine  argols  10*18  per  cent.  A  solution  of  the  argols  in 
hydrochloric  acid  shows  the  presence  of  potassium,  calcium  Avith  a  trace 
of  magnesium  and  iron  in  that  from  white  wine ;  that  from  the  red 
wine  only  potassium  and  calcium. 
Five  samples  of  tartaric  acid  were  next  estimated.  Three  were  of 
known  make,  one  of  these  (No.  3)  being  in  crystals,  and  two  (Nos.  4 
and  5)  unknown.  The  samples  known  are  from  the  leading  manu- 
facturing chemists  and  will  thus  give  a  fair  estimation  of  the  purity 
of  the  commercial  article. 
