Aocfober^i898rm-}         Analysis  of  Lemon  Syrups.  495 
chloride  and  silver  nitrate.  A  third  portion  was  acidified  with 
hydrochloric  acid  and  tested  for  boric  acid  with  turmeric  paper. 
Oxalic  acid  was  tested  for  by  heating  an  aqueous  solution  with 
neutral  calcium  acetate.  For  the  detection  of  salicylic  acid  an 
aqueous  solution  was  shaken  with  chloroform,  the  chloroform 
removed  and  filtered  repeatedly  through  dry  filter-paper  until  clear, 
evaporated,  the  residue  taken  up  with  water,  and  a  dilute  solution 
of  ferric  chloride  added. 
The  heavy  metals  were  tested  for  by  sulphuretted  hydrogen  and 
ammonium  sulphide.  The  total  acidity  was  determined  by  titration, 
and  from  the  result  that  due  to  tartaric  acid  was  deducted,  the 
remainder  being  reckoned  as  citric  acid. 
The  tartaric  acid  was  determined  by  precipitating  as  acid  potas- 
sium tartrate  and  titrating.  To  a  solution  of  20  grammes  of  the 
syrup  was  added  5  grammes  of  potassium  chloride,  the  solution 
neutralized  with  solution  of  potash  and  made  up  to  50  c.c.  A  solu- 
tion of  5  grammes  of  citric  acid  was  then  added,  the  solution  stirred, 
allowed  to  stand  over  night,  the  precipitated  acid  potassium  tartrate 
washed,  first  with  a  saturated  solution  of  cream  of  tartar,  and  after- 
wards twice  with  a  10  per  cent,  solution  of  potassium  chloride,  and 
finally  titrated  hot. 
For  the  detection  of  soluble  starch,  gum  and  dextrin,  a  moderately 
strong  solution  was  mixed  with  six  times  its  bulk  of  absolute  alcohol, 
the  alcohol  removed,  the  residue  dissolved  in  water,  and  alcohol 
again  added,  and  the  same  procedure  repeated  until  the  residue 
contained  nothing  further  of  a  reducing  nature.  The  residue  was 
then  dissolved  in  water,  boiled  for  fifteen  minutes  with  hydrochloric 
acid,  neutralized  and  tested  with  Fehling's  solution. 
For  the  detection  of  gelatin  an  aqueous  solution  was  tested  direct 
with  a  solution  of  tannin.  As,  however,  the  presence  of  much  citric 
acid  hinders  the  precipitation,  it  is  advisable  to  first  neutralize  with 
soda.  The  presence  of  an  excess  of  soda,  on  the  other  hand,  redis- 
solves  the  precipitate. 
For  the  determination  and  identification  of  the  sugar,  a  solution 
was  made  by  dissolving  5  grammes  in  100  c.c.  of  water.  For  the 
determination  of  the  reducing-sugar  25  c.c.  of  the  solution  were  neu- 
tralized with  soda  and  diluted  to  100  c.c.  Ten  c.c.  of  Fehling's 
solution  and  40  c.c.  of  water  were  then  added  and  the  titration  car- 
ried out  according  to  Soxhlet's  directions.    As  the  solution  of  the 
