THE  AMEKICAST 
JOURNAL  OF  PHARMACY 
IS  THERE  CARAMELIZATION  IN  RIVAS'S  TEST?* 
The  object  of  this  paper  is  to  show  that  several  phenomena 
accounted  for  by  an  assumption  of  caramelization  may  be  accounted 
for  by  facts  known  to  many  chemists.  The  paper  includes  an  experi- 
mental examination  of  one  case  where  caramelization  had  been 
assumed  by  way  of  explanation. 
In  a  paper  read  some  years  ago  before  the  Pennsylvania  Phar- 
maceutical Association,  W.  F.  Horn  called  attention  to  the  fact 
that  when  syrup  of  ferrous  iodide  has  turned  brown  from  age  "  we 
can  readily  restore  its  original  color  by  boiling  it  in  a  flask  for  a  few 
minutes."  1  J.  P.  Remington  in  discussing  this  point  stated  that  one 
cannot  "decolorize  such  syrup  without  the  use  of  animal  charcoal, 
because  of  the  caramelization."  2  In  a  recent  paper,  West  accounted 
for  the  appearance  of  yellow  to  brown  colors  on  heating  glucose 
broths  with  sodium  hydroxide  in  Rivas's  Test  for  B.  Qoli  by  stating 
that  "  The  sugar  is  probably  caramelized  by  the  NaOH."  "  Lactose 
solution  also  becomes  yellow  to  brown,  depending  on  the  amount  of 
sugar."  3    More  recently,  in  the  discussion  of  the  brownish  color 
*  Presented  at  the  meeting  of  the  Phila.  Section  of  the  Amer.  Chem. 
Soc.,  Jan.  20,  1910.  Reread  (by  request)  at  the  fifth  Pharmaceutical  Meet- 
ing for  1909-1910  at  the  Philadelphia  College  of  Pharmacy,  Feb.  15,  igro. 
1  Proceedings  Penna.  Pharm.  Assoc..  1903,  p.  T12. 
2  Ibid.,  p.  113. 
3  Amer.  Jour.  Public  Hygiene,  19,  p.  228,  1909.  Mr.  West's  statement 
was  evidently  not  intended  as  more  than  a  suggestion,  for  in  a  private 
communication,  Feb.  15,  1910,  he  frankly  states  that  he  "has  no  sure  ground 
to  base  his  assertion  on." 
APRIL,  icjio 
By  David  Wilbur  Horn,  Ph.D. 
(151) 
