364  Scientific  and  Technical  Abstracts.  {Am-^°auyr;i^iarm' 
given  is  probably  the  more  convenient  expression.  The  salt  is  soluble 
in  water  to  the  extent  of  1  part  in  50.  After  drying  in  desiccator  for 
some  hours  the  salt  melts  at  960,  much  below  the  m.p.  of  either  of 
its  constituents. — D.  B.  Dott,  Pharm.  Journal  and  Pharmacist, 
March,  1921. 
Theobromine  and  Caffeine;  Reaction  to  Distinguish. — 
The  difference  between  the  behaviour  of  theobromine  bismuthic 
iodide  and  the  corresponding'  compound  of  caffeine  towards  the  re- 
ducing action  of  hydriodic  acid  may  be  used  to  differentiate  these  two 
substances.  The  test  is  conveniently  performed  as  follows : — 0.05  g. 
of  theobromine  or  caffeine  is  shaken  with  10  c.  c.  of  water  and 
0.5  c.  c.  of  freshly  prepared  potassium  bismuthic  iodide  solution. 
In  each  case  an  orange-coloured  precipitate  is  formed,  and 
5  drops  of  a  10  per  cent,  tincture  of  iodine  (not  freshly  prepared,  so 
that  it  may  contain  a  small  proportion  of  hydriodic  acid)  is  added. 
The  colour  of  the  caffeine  bismuthic  iodidei  precipitate  changes  to  a 
bright  red,  whilst  the  theobromine  precipitate  becomes  brown  in  15 
mins.,  and  dark  chocolate  brown  in  less  than  30  mins:,  owing  to  re- 
duction. A  dilute  solution  of  hydriodic  acid,  containing  not  more 
than  1  per  cent,  of  hydrogen  iodide,  may  be  used  instead  of  the  tinc- 
ture of  iodine. — M.  Malmy,  through  Journ.  of  the  Society  of  Chem- 
ical Industry,  March,  1921. 
A  New  Compound  of  Barbituric  Acid. — At  a  recent  meeting 
of  the  Societe  de  therapeutique,  Paris,  a  new  compound  of  barbituric 
acid  was  described  by  Daniel  Bardet  (LJ Union  pharm.,  Jan.,  1921,  p. 
1 ) .  This  is  diethyl-diallyl-barbiturate  of  diethylamine,  and  is  a  com- 
bination of  diethyl-barbituric  acid  (veronal)  and  diallyl-barbituric 
acid  (dial)  with  diethylamine.  This  compound  is  soluble  in  water 
1  :  3,  this  solution  containing  10  per  cent,  of  veronal  and  10  per  cent, 
of  dial.  Such  a  concentrated  solution  is  easily  injectable  subcutane- 
ously  or  intravenously,  and  is  accordingly  very  convenient  of  admin- 
istration and  rapid  in  its  effects.  Daniel  states  that  this  new  com- 
pound is  non-toxic  in  ordinary  effective  doses ;  its  action  is  on  the  cen- 
tral nervous  system  ;  it  can  be  employed  as  an  anaesthetic  in  operations 
not  requiring  complete  muscular  relaxation ;  it  is  a  valuable'  adjunct 
to  general  anaesthesia,  suppressing  the  period  of  excitation  and  allow- 
ing of  the  employment  of  a  minimum  quantity^  of  anaesthetic ;  it 
has  the  drawback  of  not  always  giving  the  same  results  in  the  same 
