Am.  Jour.  Pharm.  > 
April,  1876.  J 
Reviews,  etc. 
191 
Chemie,"  (annual  report  on  the  progress  of  chemistry)  for  which  he  has  elaborated 
the  same  branch  since  1867.  The  second  volume  is  in  charge  of  the  editor  of  the 
entire  woik,  Professor  Kraut,  of  Hannover,  who  completed  Gmelin's  organic  chem- 
istry with  its  supplements  in  1870.  The  completion  of  the  inorganic  chemistry 
may  now  doubtless  be  looked  for  in  a  short  time. 
Ueber   die   nvesentlichen   Bestandtheile  <von  Gehemium   sempernj'irens.      Von  Dr. 
Chas.  A.  Robbins.   Berlin,  1876. 
On  the  proximate  principles  of  Gels,  sempervirens. 
The  results  of  the  author  agree  in  the  main  with  those  previously  obtained 
by  Professor  Wormley  (Amer.  Jour.  Phar.,  1870,  p.  1,).  The  gelseminic 
acid  of  the  latter  was  found  by  Dr.  Robbins  to  be  identical  with  aesculin, 
and  the  amorphous  gelseminia,  for  which  the  empirical  formula  CnH19N02  was 
obtained,  was  observed  to  have  the  reactions  noticed  by  Wormley  5  but  a  solution 
of  gelseminia  in  concentrated  sulphuric  acid  acquires,  on  the  addition  of 
potassium  bichromate,  particularly  at  the  place  of  contact,  a  very  characteristic 
cherry-red  color  having  a  tint  of  violet  and  changing  to  blueish-green.  The 
sulphuric  acid  solution  of  gelseminia  spread  over  a  porcelain  plate  acquires,  on  the 
addition  of  ceroso-ceric  oxide,  a  rose-cherry  red  color  surrounding  the  oxide,  and 
spreading  over  the  entire  surface  after  stirring  with  a  glass  rod.  This  reaction  is 
quite  characteristic  and  very  delicate. 
The  resins,  freed  from  gelseminia,  were  found  to  be  destitute  of  poisonous  action 
upon  rabbits  and  pigeons. 
Ein  Beitrag  zur  Phartnacognostichen  und  Chemischen  Kenntniss  des  Cacaos.  Von 
Piers  Trojanowsky.    Dorpat,  1875. 
A  Contribution  to  the  Pharmacognostical  and  Chemical  Knowledge  of  Cacao. 
This  inaugural  dissertation,  for  which  the  experiments  were  made  in  Prof.  Dra- 
gendorff's  laboratory,  treats,  in  the  first  part,  of  the  pharmacognostical  relations,  giv- 
ing brief  historical  notes,  botanical  accounts,  notes  on  the  culture  and  descriptions 
of  the  twenty  commercial  varieties  investigated  by  the  author. 
The  second,  or  chemical  part,  contains  a  review  of  the  various  analyses,  which  is 
followed  by  the  quantitative  determination  of  theobromina.  This  was  effected  by 
first  treating  the  coarsely  powdered  material  with  petroleum  benzin,  to  remove  fat  j 
the  residue  is  then  rubbed  with  powdered  glass  and  water  to  a  fine  powder ;  mag- 
nesia is  added,  and  the  mixture  dried  below  700  C.  This  residue  is  exhausted  with 
two  portions  of  boiling  alcohol,  and  the  filtered  solution  evaporated  5  a  little  fat  and 
a  minute  amount  of  a  crystallizable  body  are  removed  by  petroleum  benzin,  the  un- 
dissolved portion  washed  upon  a  tared  filter  with  alcohol  until  the  filtrate  is  nearly 
colorless,  and  the  residue  weighed  as  theobromina  j  to  this  weight  is  added  the 
amount  of  alkaloid  dissolved  in  the  alcoholic  washings  (1  in  1460).  In  this  man- 
+  ner  the  author  obtained  from  the  cotyledons  of  a  Domingo  cacao  I'aqf;  and  from 
an  African  cacao  4-652  per  cent,  of  theobromina.  Different  samples  of  the  same 
commercial  varieties  yielded,  however,  very  different  amounts.  The  shells  of  the 
same  varieties,  mentioned  before,  gave  respectively  2*056  and  4*540  per  cent,  of  the- 
obromina, the  smallest  yield  being  obtained  from  the  shells  of  a  Soconusco  cacao 
=o*866  per  cent. 
The  amount  of  fat  obtained  by  petroleum  benzin  varied  between  39*30  per  cent, 
from  a  Carracas  and  52*05  per  cent,  from  a  Surinam  cacao.  The  fusing  point  of 
the  cacao  butter,  determined  in  capillary  glass  tubes,  varied  between  300  C.=86°  F. 
(Brazil  cacao)  and  32*8°  C.=9i°  F.  (St.  Lucia  cacao).  To  determine  whether 
cacao  butter  has  been  adulterated  with  other  fats,  the  author  recommends  the  pro- 
cess proposed  by^  Bjorklund,  in  1864.  Two  grams  of  the  fat  are  dissolved,  by  agi- 
tation, in  a  strong  glass  tube;  in  4  grams  of  ether  of  170  C  (62*6  0  F.)  ;  the  tube  is 
