Am.  Jour.  Pbarm.1 
March.  1901.  J 
Why  do  Syrups  Spoil  ct 
123 
possessed  by  ultramarine,  it  may  readily  be  seen  what  reactions  the 
pigment  would  effect  in  the  individual  syrups. 
On  allowing  a  simple  syrup,  made  by  the  cold  process,  to  stand 
for  a  while,  a  deposit  forms,  consisting  of  sulphur  precipitated  as  a 
result  of  the  decomposition  of  the  ultramarine  ;  sometimes  the  pig- 
ment itself  is  also  deposited,  particularly  if  a  large  quantity  has 
been  used  in  "  whitening  "  the  sugar.  The  syrup  is  then  likely  to 
acquire  a  rather  disagreeable  odor.  If  the  syrup  is  made  by  boiling, 
the  ultramarine,  on  continued  boiling,  is  decomposed,  and  a  blackish 
scum  rises,  which  may  be  removed.  A  syrup  made  by  boiling  is, 
hence,  apt  to  keep  better  than  one  not  boiled. 
In  syrup  of  acacia,  the  calcium  gummate  and  ultramarine  react,  a 
calcium  sulphide  being  formed.  The  syrup,  which  is  naturally 
prone  to  decompose  even  under  the  most  favorable  conditions  of 
preservation,  is  thus  made  to  deteriorate  with  increased  rapidity. 
In  syrups  of  citric  acid,  calcium  lactophosphate,  lemon  and  squill, 
there  are  free  acids  present,  sufficient  to  decompose  the  ultramarine 
and  render  the  syrups  unfit  for  use. 
In  syrup  of  hydriodic  acid  we  have  a  naturally  unstable  chemical 
which  requires  all  our  art  to  properly  preserve,  and  which  must  be 
particularly  well  protected  from  the  action  of  reducers.  With  such 
a  chemical,  ultramarine  immediately  gives  a  reaction.  The  syrup 
soon  develops  a  red  color  and  becomes  totally  unfit  for  use.  This 
syrup  has  been  the  subject  of  much  experiment,  with  a  view  to  find-, 
ing  means  of  rendering  it  more  stable.  Among  these  means  there 
has  been  recommended  the  partial  or  total  replacement  of  the  sugar 
by  glucose  or  glycerin.  Glucose  as  ordinarily  found  on  the  market 
is  unfit  for  this  purpose,  as  it  nearly  always  contains  appreciable 
quantities  of  free  sulphuric  acid,  and  is,  moreover,  very  prone  to 
ferment.  Glycerin  is  totally  inadmissible,  as  it  enters  into  chemical 
reaction  with  the  hydriodic  acid,  the  result  being  the  formation 
of  allyl  iodide.  The  syrup  soon  develops  a  straw  color  which 
rapidly  deepens,  while  the  preparation  acquires  a  disagreeable  odor 
and  taste  which  render  the  syrup  unfit  for  use. 
In  syrup  of  ferrous  iodide  we  have  again  a  readily  changeable 
iron  salt,  subjected  in  addition  to  the  action  of  a  sulphide.  Natur- 
ally enough,  ferrous  sulphide  forms,  together  with  an  unstable  iodide 
from  which  free  iodine  is  soon  liberated.  In  this  syrup  glycerin 
would  be  a  good  preservative,  were  it  not  that  pure  syrup  is  very 
