200  Lycopersicum  Esculentum — Tomato.  ^VaTl'mz*** 
To  obtain  the  oxalic  acid,  the  precipitate  obtained  by  neutralizing 
the  original  solution  with  calcium  hydrate  was  treated  with  hydro- 
chloric acid,  the  solution  diluted,  filtered  and  neutralized  by  ammonia; 
when  calcium  oxalate  was  precipitated. 
This  was  boiled  with  a  solution  of  potassium  carbonate  for  two 
hours,  and  filtered  to  separate  calcium  carbonate.  The  filtrate  was 
then  mixed  with  alcohol  to  just  below  the  point  of  precipitation,  and 
the  mixture  treated  with  dilute  sulphuric  acid.  The  potassium  sul- 
phate being  insoluble  in  alcohol,  readily  subsided,  leaving  oxalic  acid 
in  alcoholic  solution. 
This  was  then  partially  evaporated  and  set  aside.  After  standing 
several  days  a  deposit  of  coloring  and  extractive  matter  was  formed. 
This  was  separated,  and  the  solution  further  concentrated  and  treated 
with  animal  charcoal. 
After  a  few  days  I  obtained  a  quantity  of  small  crystals.  These 
were  dissolved  in  a  small  quantity  of  distilled  water,  and  again  treated 
with  animal  charcoal  and  recrystallized.  The  yield  was  about  equal 
to  that  of  malic  acid. 
The  second  process  was  as  follows  :  One  gallon  of  fresh  juice  was 
boiled  down  to  the  measure  of  two  pints.  This  was  set  aside  and 
occasionally  observed.  After  it  had  been  standing  about  two  weeks 
I  found  no  result  except  the  formation  of  a  considerable  brown  depo- 
sit of  extractive.  It  was  then  mixed  thoroughly  and  evaporated  at  a 
gentle  heat  to  about  three  fluidounces. 
This  was  then  operated  on  in  essentially  the  same  manner  as  the 
first,  diluting  the  liquid,  filtering  and  neutralizing  with  calcium  hy- 
drate, and  then  isolating  the  acids  from  their  lime  salts. 
The  results  were  similar,  the  yield  of  malic  acid  being  rather  larger. 
It  has  been  stated  tartaric  acid  existed  in  tomatoes  in  small  quanti- 
ties. I  failed  to  obtain  it,  but  hope  at  some  future  time  to  continue 
an  investigation  of  various  small  acid  fruits,  and  repeat  that  of  toma- 
toes with  better  facilities.  I  infer  from  the  results  obtained  that  the 
acids  exist  uncombined  in  the  fruit. 
It  is  evident,  however,  that  tomatoes  are  not  available  as  a  source 
•f  either  of  the  acids. 
