400 
Chemical  Notes. 
j  Am.  Jour.  IMiarm, 
(       Aug.,  1881. 
On  the  Aetion  of  Potassium  Nitrite  upon  Ammonium  Chloride. — It 
has  long  been  known  that  when  a  solution  of  potassium  nitrite  and 
ammonium  chloride  is  heated  water  and  nitrogen  are  formed.  But  ir 
a  mixture  of  dry  potassium  nitrite  and  dry  ammonium  chloride  is 
heated  such  is  not  the  case.  Dr.  D.  Tommasi  finds  that  the  products 
of  this  reaction  are  very  complex,  and  their  nature  depends  on  the 
quantity  of  the  salt  used,  and  particularly  on  the  temperature  to  which 
the  mixture  is  heated.  If  10  grams  of  potassium  nitrite  are  melted  in 
a  porcelain  crucible,  and  then  a  small  quantity  of  ammonium  chloride 
be  added,  we  notice  that  this  salt  commences  to  rotate  with  a  variable 
velocity,  and  then  takes  fire  and  burns  with  a  violet-purple  flame,, 
accompanied  by  a  feeble  detonation;  in  fact  it  behaves  exactly  like  a 
globule  of  potassium  burning  upon  water.  With  ammonium  sulphate 
the  phenomenon  is  more  striking,  but  only  very  small  quantities  should 
be  used,  or  the  experiment  will  become  dangerous  on  account  of  the 
projections.  The  products  of  the  reaction  between  potassium  nitrite 
and  ammonium  chloride  are :  potassium  chloride,  ammonia,  nitrous 
fumes,  and  probably  nitrogen  as  well.  Ammonium  nitrate,  when  in 
contact  with  melted  potassium  nitrite,  produces  a  remarkable  luminous 
phenomenon.  If  the  ammonium  nitrate  is  in  small  crystals,  a  series 
of  phosphorescent  j)oints  are  formed  ;  but  if,  on  the  contrary,  one  crys- 
tal, liowever  small,  be  introduced,  it  forms  a  globule  surrounded  by  a 
])hosphorescent  ring,  and  it  rotates  witii  great  rapidity,  and  then  sud- 
denly explodes,  producing  a  beautiful  flame. — Chem.  News,  May  27, 
1881,  p.  241. 
Organic  Chemistry. — Essential  Oil  from  Hemp. — The  essential 
oil  from  cannabis  indica  has  already  been  examined  by  Bohlig  and  by 
Personne,  the  latter  of  whom  obtained  from  it  a  liquid  and  a  solid 
hydrocarbon.  L.  Valente  has  prepared  the  essential  oil  from  ordinary 
hemp  {cannabis  sativa),  by  distilling  the  fresh  leaves  Avith  water  and 
agitating  the  milky  distillate  with  ether.  The  oil  dried  over  calcium 
chloride  and  distilled  repeatedly  from  sodium  is  colorless  and  mobile 
(boiling-point  256°  to  258°C.)  Its  specific  gravity  at  0°  referred  to 
water  is  0*9292.  The  analyses  agreed  with  the  formula  CijHg^ ;  the 
vapor  density,  however,  could  not  be  determined  by  the  ordinary 
methods,  as  it  decomposes  at  300°C.  The  oil  mixes,  in  all  proportions, 
with  alcohol,  ether  and  chloroform.  Bromine  acts  energetically  on  it, 
forming  a  crystalline  compound  which  has  not  yet  been  investigated. . 
