412  Inversion  of  Cane  Sugar  in  Syrups.     { As™ptemUberPi9iT' 
(2)  Determination. 
Transfer  25  Cc.  each  of  the  copper  and  alkaline  tartrate  solutions 
to  a  400  Cc.  Jena  or  Non-sol  beaker  and  add  50  Cc.  of  reducing 
sugar  solution,  or,  if  a  smaller  volume  of  sugar  solution  be  used,  add 
water  to  make  the  final  volume  100  Cc.  Heat  the  beaker  upon  an 
asbestos  gauze  over  a  Bunsen  burner,  so  regulate  the  flame  that 
boiling  begins  in  four  mirtutes,  and  continue  the  boiling  for  exactly 
two  minutes.  Keep  the  beaker  covered  with  a  watch-glass  through- 
out the  entire  time  of  heating.  Without  diluting,  filter  the  cuprous 
oxide  at  once  on  an  asbestos  felt  in  a  porcelain  Gooch  crucible,  using 
suction.  Wash  the  cuprous  oxide  thoroughly  with  water  at  a  tem- 
perature of  about  6o°  C,  then  with  10  Cc.  of  alcohol,  and  finally  with 
10  Cc.  of  ether.  Dry  for  thirty  minutes  in  a  water  oven  at  ioo°  C, 
cool  in  a  desiccator,  and  weigh  as  cuprous  oxide. 
N.  B. — The  number  of  milligrammes  of  copper  reduced  by  a 
given  amount  of  reducing  sugar  differs  when  sucrose  is  present  and 
when  it  is  absent.  In  the  tables  following,  the  absence  of  sucrose  is 
assumed,  except  in  the  two  columns  under  invert  sugar,  where  one 
for  mixtures  of  invert  sugar  and  sucrose  (0.4  gramme  of  total  sugar 
In  50  Cc.  of  solution)  and  one  for  invert  sugar  and  sucrose  when  the 
50  Cc.  of  solution  contains  2  grammes  of  total  sugar  are  given,  in 
addition  to  the  column  for  invert  sugar  alone  (U.  S.  Dept.  of  Agr., 
Bur.  of  Chem.,  Bull.  107,  rev.,  pages  241  and  242). 
The  cold  percolation  process  sample  contained  0.174  per  cent, 
invert  sugar. 
The  hot  process  sample  contained  0.138  per  cent,  invert  sugar. 
The  cane  sugar  from  which  the  syrups  were  made  was  tested  by 
the  same  method  and  contained  0.111  per  cent,  invert  sugar,  thus 
indicating  that  in  the  process  of  making  the  samples  very  little 
inversion  had  taken  place. 
The  syrups  were  then  placed  in  a  cool,  dark  place,  samples  being 
taken  from  them  at  frequent  intervals  and  tested,  with  the  following 
results : 
Cold  Hot 
January  28,  1915  (the  day  the  samples  were  prepared) 0.174%  0.138%  invert  sugar 
February  10,  1915  0.172%  0.171%  invert  sugar 
February  25,  1915  0.292%  0.170%  invert  sugar 
March  9,  1915  0.559%  0.401%  invert  sugar 
March  23,  1915  1.123%  1.061%  invert  sugar 
April  2,  1915  1.807%  1.595%  invert  sugar 
