276 
Chocolate. 
/Am.  Jour.  Pharm. 
\      June,  1885. 
increased.  Only  a  small  quantity  of  distillate  was  obtained.  The 
glycerin  used  in  these  experiments  had  a  specific  gravity  at  15°  C.  of 
1*257,  and  otherwise  came  up  to  the  requirements  of  the  Pharmacopoeia. 
The  statement  has  been  made  (Gerlach,  Zeitschrift  fiir  analytische 
Chemie/'  24,110)  that  absolute  glycerin,  specific  gravity  1'2653,  boils 
at  290°  C,  and  that  95  per  cent,  glycerin,  sp.  gr.  1-2526,  boils  at  164° 
C.  This  practically  corresponds  to  the  experience  above  given,  as 
very  small  differences  in  specific  gravity  make  widely  different  boiling 
points. 
In  view  of  these  facts  it  is  evident  that  the  boiling  point  given  in  the 
Pharmacopit'ia  should  be  not  below  16.i.°C,  instead  of  290°  C.  which  is 
for  absolute  glycerin. 
CHOCOLATE. 
By  jAJtES  Hkrvy  Hagexbuch,  Ph.  G. 
Abstract  from  ari  Inaugural  Essaij. 
There  are  several  different  ways  of  preparing  chocolate.  The  best, 
and  the  one  most  generally  used,  is  to  take  chocolate  nibs  (which  are 
the  seeds  deprived  of  their  outer  covering)  and  grind  them  to  a  smooth 
paste  in  a  mill  \vith  rollers,  which  are  heated  by  passing  steam  into 
them  by  means  of  a  i)ipe.  To  this  paste  the  sugar  and  flavoring  sub- 
stances, principally  vanilla  or  cinnamon,  are  added,  and  the  whole 
reduced  to  a  homogeneous  mass,  is  moulded  into  cakes  ready  for  the 
market.  The  heated  rollers  are  used  because  they  melt  the  fatty  sub- 
stance in  the  ''nibs,"  and  thus  facilitate  the  making  of  the  paste. 
Unadulterated  chocolate  is  compact,  brittle,  breaking  with  a  smooth 
fracture,  has  a  dark  reddish  brown  color,  and  forms  a  perfectly  homo- 
geneous mass  when  worked  into  a  paste.  It  should  dissolve  easily  in 
the  mouth,  without  leaving  any  gritty  particles  behind.  The  adulte- 
rations are  very  numerous,  being  composed  principally  of  potato 
starch,  fiour,  earthy  matter,  paraffin,  tallow,  lard,  and  other  animal 
fats.  Though  nearly  all  the  different  kinds  of  chocolate  contain 
starch  it  is  nevertheless  considered  an  adulterant.  It  makes  a  heavy 
and  indigestible  compound,  because  starch,  unless  boiled,  is  far  from 
being  digestible.  Blythe  says  that  it  is  considered  an  adulterant 
because  it  contains  no  nitrogenous  principles,  which  are  the  main,  and 
most  valuable  parts  of  the  cacao,  the  principal  ingredient  of  chocolate. 
