272 
REACTION  FOR  CAFFEINE. 
When  the  precipitate  of  myristate  of  magnesia  has  been  decom- 
posed, and  the  myristic  acid  dissolved  by  alcohol,  a  residue  is  left. 
This  is  a  new  body,  to  which  the  author  gives  the  name  of  Otobite. 
After  it  was  purified  by  recrystallization  from  hot  alcohol  and 
ether,  its  composition  was  D*4H1305.  It  is  inodorous  and  taste- 
less, insoluble  in  water,  and  crystallizes  in  good-sized  shining 
prisms.  It  fuses  at  271°.4  F.,  and  solidifies  again  in  a  crystal- 
line form.  When  heated  beyond  this  point  it  solidifies  in  an  amor- 
phous form.  Heated  on  platinum  foil,  it  evolves  aromatic  fumes, 
and  then  burns  with  a  smoky  flame.    Its  analysis  gave  : — 
Carbon 
73.19 
72.85 
24 
73.09 
Hydrogen 
7.35 
6.46 
13 
6.59 
Oxygen 
20.46 
20.68 
5 
20.30 
London  Chem.  Gaz.,  Feb.l,  1855,  from  Liebig's  Annaleru 
REACTION  FOR  CAFFEINE. 
By  Prof.  W.  Delffs. 
If  a  solution  of  iodide  of  potassium  and  mercury,  (obtained  by 
saturating  iodide  of  potassium  with  red  oxide  of  mercury)  be 
added  to  a  solution  of  caffeine,  a  precipitate  is  produced,  which 
in  a  short  time  forms  an  aggregation  of  shining,  white,  acicular 
crystals.  The  other  alkaloids — cinchonine,  cinchonidine,  qui- 
nine, paricine,  strychnine,  leucine,  morphine,  codeine,  papave- 
rine,narcotine,  delphinine,  emetine, veratrine,  atropine,  bebeerine, 
aconitine,  solanine,  oxyacanthine,  piperine,  nicotine,  and  coniine, 
—  also  furnish  precipitates  with  this  reagent,  even  when  diluted 
60,000  times,  but  these  remain  amorphous. — Chem.  Gaz,  Feb. 
15,  1855,  from  Neues  Jahrb.  fitr  Pharm. 
