NITRATE  AND  NITRITE  OF  ETHYL. 
69 
badly.  At  2°  C.  1  part  of  this  salt  requires  0-63  parts  of 
water  to  dissolve  it.  It  forms  double  salts  with  the  magnesian 
sulphates,  and  these  double  salts  are  isomorphous  with  those 
formed  with  the  same  sulphates  and  the  sulphates  of  potash  and 
ammonia.  With  sulphate  of  alumina  the  sulphate  of  caesium 
forms  a  very  brilliant  octohedral  alum. 
The  chloride  crystallizes  in  cubes,  but  it  is  distinguished  from 
those  of  potassium  and  rubidium  by  being  deliquescent,  like  the 
chloride  of  lithium.  It  is  fusible  and  volatile  at  a  comparatively 
moderate  temperature. 
Caesium  is  less  abundant  than  rubidium,  which,  however  it 
generally  accompanies  ;  the  richest  source  is  the  mineral  water 
of  Durckheim.  10  kilogrammes  of  this  water  contain  2  milli- 
grammes of  chloride  of  caesium  ;  and  it  has  been  from  the  resi- 
due of  the  evaporation  of  this  water  that  I  have  prepared  it,  by 
precipitating  it  with  bichloride  of  platinum,  and  submitting  the 
alkaline  chloroplatinate  to  successive  exhaustions  with  boiling 
water  until  only  the  chloroplatinate  of  caesium  was  left,  this,  as 
we  have  seen,  being  the  most  insoluble  of  all,  and  possessing  also 
the  highest  equivalent. 
The  lepidolites  contain  only  traces  of  caesium,  but,  on  the 
contrary,  they  are  rich  in  rubidium,  and  it  is  from  these  that 
M.  Bunsen  has  prepared  the  latter.  The  lepidolite  from  Rosena 
(Moravia)  contains  two-thousandths  of  its  weight  of  oxide  of 
rubidium,  and  that  from  Saxony  appears  still  richer.  Probably 
all  the  saline  mineral  waters  contain  it ;  that  of  Durckheim  con- 
tains two-millionths,  and  the  mother-liquor  about  four  hundred- 
thousandths  of  chloride  of  rubidium.  Commercial  potash,  how- 
ever, does  not  always  contain  it. — Ohem.  News,  London,  Oct. 
26,  1861,  from  Annal.  der  Physik  und  Chem. 
ON  THE  PREPARATION  OF  NITRATE  AND  NITRITE  OF  ETHYL. 
By  M.  Carey  Lea. 
Nitrate  of  Ethyl. — The  tendency  of  alcohol  to  decompose  ni- 
tric acid  is  so  great,  that  while  we  have  any  number  of  processes 
for  obtaining  nitrite  of  ethyl,  Millon's  is  the  only  one  known  for 
forming  the  nitrate.  But  Millon's  process  fails  much  oftener 
than  it  succeeds  (such,  at  least,  has  been  my  experience),  in 
