36'6 
Chemical  Notes. 
(  Am.  Jour.  Pharm. 
\      July, 1880. 
two  flasks  containing  the  hair-weeds  he  boiled  to  destroy  the  life  of  the 
weed  and  its  spores.  All  three  flasks  were  then  sealed  hermetically  and 
allowed  to  stand  under  similar  conditions.  On  opening  them  it  was 
found  that  only  the  flask  containing  the  living  hair-weeds  gave  ofF 
sulphuretted  hydrogen.  The  other  flasks  remained  unchanged  during 
several  months.  At  the  end  of  six  months,  however,  the  flask  into 
which  the  dead  organic  matter  had  been  put  was  found  to  smell  faintly 
of  sulphuretted  hydrogen  and  on  examination  hair-weeds  were  found 
in  it. — Chem.  News^  May  21,  p.  236. 
Action  of  Potassium  Permanganate  upon  Potassium  Cyanide. — E.  Bau- 
drimont  has  found  that  when  the  solution  is  alkaline  the  result  of  the 
reaction  is  an  abundance  of  nitrous  fumes  and  relatively  little  urea  ;  if 
some  acid  (sulphuric),  however,  is  added,  urea  is  formed  in  abundance 
and  with  it  carbonic,  nitric,  formic  and  oxalic  acids,  the  latter  as  a 
decomposition  product  of  the  urea.  The  formation  of  these  products 
is  illustrated  by  equations. — Compt.  Rend.^  89,  1 115. 
Dissociation  of  Iodine  and  other  Halogen  Elements. — J.  M,  Crafts 
announced  recently  (this  journal.  May  1880,  p.  262)  that,  while  free 
chlorine  showed  a  normal  density  and  was  not  dissociated  even  at  the 
highest  temperatures,  free  iodine  was  dissociated  and  apparently  gave  a 
density  two-thirds  of  the  normal  value  as  first  stated  by  Prof.  Victor 
Meyer.  Crafts  has  repeated  and  extended  his  observations  and  now 
gives  the  following  as  a  summary  of  his  results  : 
Per.  cent. 
Temperature. 
Density 
of  Normal  Density. 
455° 
8-705   8785  875 
677°— 682° 
8-o6;  8-58 
0-94 
757°— 770"— 765° 
8  05  J  8-28 
0-93 
831°— 878° 
8-045  8-11 
0.92 
1039° — 1 059°- -1 030° 
7-185  7-02 5  6^83 
o-8i 
1270°  1  2-8'D° 
6-075  5'57 
0.66 
1390° 
5"23;  5"3i 
o-6o 
1468*^ 
5-065  5-07 
0-58 
He  concludes  from  these  experiments  that  the  vapor-density  of  iodine 
compared  with  air,  diminishes  progressively  with  the  increase  of  tem- 
perature between  about  600°,  when  it  is  still  normal,  to  about  1470°, 
where  it  is  only  0*58  of  the  normal  density,  and  he  supposes  that  a 
still  higher  temperature  than  that  which  he  has  thus  far  been  able  to 
obtain  would  give  a  half  normal  density.  If  this  phenomenon  is 
attributed  to  a  dissociation  it  must  be  interpreted  to  mean  that  the  mole- 
cule I2  is  separated  into  two  atoms  14-1  or  else  that  a  group  which 
