Am:^prn;rS93arm"}  Coca  Leaves.  189 
zine  is  undoubted,  but  it  was  only  after  piperazine  had  been  pre- 
pared from  dinitrosodiphenylpiperazine  that  Hofmann  succeeded  in 
identifying  it  and  isolating  the  pure  crystalline  product  from  the 
mixture,  which,  besides  higher  ethylene  bases,  contained  also 
a  number  of  vinyl  compounds. 
Owing  to  the  difficulty  of  purifying  small  quantities  of  the  base, 
Ladenburg's  experiments  with  diethylenediamine,  obtained  by  the 
decomposition  by  heat  of  ethylenediamine  hydrochloride,  were 
unsuccessful :  the  product  described  by  Ladenburg  as  the  base  was 
undoubtedly  impure  piperazine  carbonate,  as  proved  by  its  melting 
point,  159-1630. 
In  conclusion,  it  may  be  interesting  to  mention  that  we  have  suc- 
ceeded in  preparing  the  following  series  of  hydrates  of  piperazine, 
that  most  readily  formed  being  a  hexhydrate  which  crystallizes 
from  dilute  aqueous  solutions: 
C4H10N2-H2O,  m.  p.  750, 
"       2H20,     "  560, 
"       3H20,      "  39-40°, 
"       4H20,      "  42-43°, 
"       5H20,      «  45°, 
6H20,      "  480. 
COCA  LEAVES.1 
By  O.  Hesse. 
In  this  paper,  the  author  gives  a  short  account  of  the  various 
substances  which  have  been  obtained  from  coca  leaves ;  with  a  few 
exceptions,  most  of  the  compounds  here  referred  to  have  been  pre- 
viously described  by  the  author  (A.  J.  Ph.,  1889,  p.  296),  Liebermann, 
Einhorn,  Giesel  and  others  (see  Am.  Jour.  Phar.,  1889,  433;  1890, 
p.  422;  1892,  p.  44). 
Cinnarnylcocdine  hydrochloride,  C19H23N04,HC1  +  2H20,  crystal- 
lizes from  water,  in  which  it  is  readily  soluble,  in  lustrous  plates, 
loses  its  water  at  66°,  and  melts  at  1760;  its  specific  rotatory 
power  in  aqueous  solution  is  [«]D  =  —  104-1.  The  platinochloride , 
(C19H23N04)2H2PtCl6,  crystallizes  in  small  needles,  and  is  moder- 
ately easily  soluble  in  boiling  water.  The  aurochlonde,  C19H23N04, 
HAuCI4,  crystallizes  in  small  yellow  needles,  and  melts  at  1 560. 
The  methiodide,  C19H23N04,MeI,  crystallizes  from  alcohol  in  small, 
1  Annalen,  271,  180-228  ;  Jour.  Chem.  Soc,  1893,  Abstr.  I,  p.  57. 
