446  Gleanings  from  the  Foreign  Journals.  {^l^\l^m- 
are  heated  in  a  flask  with  20  to  25  grams  of  crude  nitric  acid,  sp.  gr. 
1*32,  and  boiled  for  one  miuute.  An  equal  volume  of  cold  water  is 
now  added,  and,  with  constant  agitation,  an  excess  of  ammonia  ;  the 
liquid  is  separated  from  the  wax,  and  poured  into  a  glass  cylinder  ;  it 
has  a  yellow  color  if  the  wax  was  pure,  and  a  more  or  less  intense  red 
brown  if  resin  was  present.  One  per  cent,  of  the  latter  may  thus  be 
readily  detected,  particularly  if  the  resulting  color  is  compared  with 
that  produced  by  pure  wax.  Nitric  acid  acts  much  more  energetically 
upon  resin  than  upon  wax. — Ber.  Chem.  Ges.^  1877,  p.  837. 
Assay  of  Cacao  and  Chocolate. — E.  Heintz  concludes  from  his 
experiments  that  cacao  dried  at  25°C.  (77°F.)  should  yield  not  over 
three  or  four  per  cent,  ashes  (Surinam  cacao  1*8  per  cent.,  Caracas  4 
per  cent.) ;  if  partly  deprived  of  the  fat,  it  still  retains  27  to  37  per 
cent,  of  it,  and  should  yield  not  over  4  to  5*5  per  cent.,  pure  chocolate 
not  over  1*5  or  1*7  per  cent,  of  ash.  Cacao  shells  yield  8*5  to  18*5 
per  cent,  of  ash,  and  if  used  for  adulterating  cacao  or  chocolate,  their 
ash  will  be  increased  in  amount. 
Twenty  grams  of  the  chocolate  or  cacao  are  exhausted  with  benzin  and 
the  solution  evaporated  ;  the  residue  is  fat,  the  purity  of  which  is  ascer- 
tained by  ether  (or  petroleum  benzin — see  May  No.,  p.  238).  The  un- 
dissolved portion  is  six  times  treated  with  water  of  I5°C.  (59°F.),  and 
the  moist  residue  examined  by  the  microscope,  by  which  foreign  starches 
and  the  spiral  vessels  and  dark-red  cells  of  cacao  shells  are  easily 
detected.  The  residue  is  washed  with  strong  alcohol  (the  filtrate  must 
not  be  deeply  colored),  dried  and  weighed.  The  weight  deducted  from 
20  grams,  less  the  weight  of  fat,  indicates  the  sugar  present,  from 
which,  however,  4  per  cent,  should  be  deducted,  which  is  the  average 
amount  of  cacao  constituents  which  are  soluble  in  water. — Arch.  d. 
Phar.,  June,  1877,  P-  506-510. 
Paullinia  pinnata,  Lin.,  is  a  tree  indigenous  to  South  America  and 
the  Antilles,  and  is  known  as  Umbo.  The  yellowish-gray  bark  of  the 
root  has  an  agreeable  musk-like  odor  and  is  used  in  the  form  of  poul- 
tice in  some  liver  affections.  Stanislas  Martin  has  analyzed  it,  and 
found  tannin,  starch,  resin,  volatile  oil  and  an  alkaloid,  timbotina,  the 
sulphate  of  which  crystallizes  in  white  needles. — Bull.  gen.  de  Thtrap. 
The  Alkaloids  of  Calabar  Bean.— Harnack  and  Witkowsky 
have  recently  investigated  this  subject  in  the  pharmacological  laboratory 
