546  Iodine  Pentahromide  and  Volatile  Oils.     {  ^™nov 
and  to  the  solution  an  excess  of  hydrochloric  acid  was  added,  which 
in  each  case  produced  a  precipitate;  this  was  weighed,  the  weight 
deducted  from  that  of  the  etherial  extract,  and  the  remainder  regarded 
as  pure  scammonin,  amounting  in  I  to  '599  gram,  or  11*98  per  cent. ; 
in  II  to  "546  gram,  or  10*92  per  cent.,  and  in  III  to  2*258  gram,  or 
45*16  per  cent.  The  precipitate  from  I  was  dark  brown,  and  was  not 
colored  brown  or  cherry-red  by  concentrated  sulphuric  acid,  nor  did  it 
acquire  a  blue  color  with  oxidizing  agents,  and  was  therefore  neither 
rosin  nor  guaiac  resin.  The  precipitates  from  II  and  III  were  light 
yellowish-brown,  became  dark  red  with  sulphuric  acid,  and  were 
regarded  as  consisting  chiefly  of  rosin. 
The  portions  dissolved  by  benzol,  oil  of  turpentine  and  alohol  were 
not  further  examined,  since  they  could  not  contain  any  scammonin. 
The  aqueous  solutions  were  heated  to  boiling ;  a  precipitate  occur- 
ring was  treated  with  solution  of  potassium  nitrate  to  ascertain  from 
the  solubility  therein  its  identity  with  vegetable  albumin.  The  boiled 
liquids  filtered  were  tested  with  subacetate  of  lead  and  with  borax  for 
coloring  matter  and  gum,  and  with  Fehling's  solution  for  sugar.  The 
re'sults  were  as  follows  : 
Fell  ling's 
Color.  Heat.  KNO3.  PbAe,  Borax.  solution. 
I.   Light  yellow.   Curdy  precp.   Soluble.   Copious  precp.   Copious  precp.   No  precp. 
II.   Straw  color.     Curdy  precp.    ^^oiu"|^3ie  Precipitate.        No  precipitate.  Precipit. 
III.   Dark  color.       Nopiecipit   ^dSolori'zed      No  precipitate.  Precipit. 
The  ashes  obtained  on  incinerating  the  samples  were  incompletely 
soluble  in  dilute  hydrochloric  acid  ;  the  acid  solutions  contained  cal- 
cium and,  in  samples  I  and  II,  also  magnesium. 
ON  THE  ACTION  OF  IODINE  PENTABROMIDE  ON 
VOLATILE  OILS. 
By  Chas.  McClellan  Forney,  Ph.G. 
From  an  Inaugural  Essay. 
The  author  prepared  iodine  pentabromide,  IBr^,  by  dissolving  127 
grains  of  iodine  in  400  grains  of  bromine.    All  the  oils  used  were  of 
the  best  commercial  quality,  and  pure.  The  test  was  applied  by  placing 
5  or  6  drops  of  the  volatile  oil  on  a  watch-crystal  and  adding  1  drop 
of  the  pentabromide.    Corresponding  experiments  were  performed, 
also,  with  the  same  volatile  oils  previously  mixed  with  25  per  cent,  of 
oil  of  turpentine  and  the  same  i)roportion  of  95  per  cent,  alcohol. 
Croton  oil  was  examined  in  the  same  manner.    The  results  are  tabu- 
lated as  follows  : 
