Am.  Jour.  Pharru. 
March,  1901. 
Why  do  Syrups  Spoil? 
121 
moreover,  has  shown  such  a  syrup  to  be  the  best  preservative  of 
unstable  chemicals,  in  the  sense  of  its  being  able  to  prevent,  or  at 
least  greatly  retard,  the  decomposition  to  which  such  chemicals  are 
prone.  Nevertheless,  substitutes  for  it  have  been  proposed  or  highly 
recommended,  among  others  the  total  or  partial  replacement  of  the 
syrup  by  glucose  or  glycerin,  or  even  both.  In  certain  syrups  addi- 
tional expedients  have  also  been  recommended,  yet,  in  my  expe- 
rience, these  substitutes  and  expedients  are  unnecessary  ;  in  fact, 
under  certain  circumstances,  they  are  more  likely  to  aggravate  mat- 
ters. 
These  substitutes  and  expedients  have  all  been  proposed  or 
recommended,  it  is  my  belief,  because  the  syrup  as  ordinarily  made 
is  not  prepared  from  suitable  materials.  We  are  all  accustomed  to 
consider  the  sugar  we  usually  buy  as  so  perfectly  fitted  for  every 
use  in  our  daily  domestic  lives,  that  the  thought  is  scarcely  likely  to 
occur  to  one  that  the  spoiling  of  a  syrup  may  be  traced  to  the 
quality  of  the  sugar  used. 
The  pharmacist  usually  obtains  his  supply  of  sugar  from  the 
grocer ;  or  he  may,  perhaps,  in  some  instances  buy  it  direct  from 
the  manufacturer  by  the  barrel.  In  neither  case,  however,  is  he 
likely  to  receive  a  pare  sugar,  simply  because  pure  sugar  has  natur- 
ally a  yellowish  color,  to  correct  which  the  manufacturer  adds  some 
blue  pigment,  usually  ultramarine  blue,  to  "  whiten  "  the  sugar — 
just  as  the  laundress  blues  her  linen,  and  for  a  similar  reason — and 
thus  to  render  it  more  agreeable  in  appearance  and  hence  more 
salable. 
Ultramarine  blue,  however,  is  an  exceedingly  mischievous  sub- 
stance when  present  in  Pharmacopoeial  syrups,  and  it  is  really  the 
most  frequent  cause  of  the  spoiling  of  the  latter.  The  quantity  of  the 
pigment  present  in  sugar  is  in  no  wise  sufficient  to  affect  the  eligi- 
bility of  sugar  as  a  daily  food,  yet  it  is  quite  sufficient  to  cause  the 
decomposition  of  easily  decomposable  chemicals.  This  will  be 
evident  if  we  consider  how  ultramarine  blue  is  made,  and  what  it 
is,  chemically. 
Ultramarine  blue  is  prepared  by  heating  together  a  mixture  of 
fine  white  clay  or  silica  with  sodium  carbonate,  sulphur  and  char- 
coal;  or,  a  mixture  of  kaolin,  sodium  sulphate,  sodium  carbonate, 
sulphur  and  charcoal.  According  to  the  proportions  taken  of  the 
several  ingredients,  ultramarines  of  various  colors  may  be  obtained. 
