398 
Chemical  Notes, 
Am.  Jour  Pharm. 
Aug.,  1880. 
iodosuiphate  of  quinia  obtained  by  my  reagent.  He  kindly  informed 
me  that  even  5  milligrams  of  quinia  were  detected  after  24  hours  by  the 
application  of  my  reagent,  and  that  the  composition  of  the  precipitated 
iodosuiphate  agreed  to  the  formula  4C2qH24N202,3H2S04,2HI,I^. 
The  Hague^  July  5,  1880. 
CHEMICAL  NOTES . 
By  Prof.  Samuel  P.  Sadtler,  Ph.D. 
Inorganic  Q\\^m\s\.VY.— Occurrence  of  Lakes  of  Sodium  Sulphate  in 
Russian  Caucasus. — -In  this  district,  in  the  neighborhood  of  the  small  town 
of  Batalpachinsk,  there  are  two  lakes  which  cover  considerable  layers 
of  sodium  sulphate,  and  from  which  the  salt  is  obtained  in  an  almost 
pure  state.  The  lakes  have  no  exit;  during  the  rainy  season  they  fill 
up,  and  in  summer  their  contents  are  partially  evaporated.  The  sul- 
phate contained  in  the  water  separates  partly  in  consequence  of  cold 
weather,  and  is  then  gotten  in  layers  of  J  inch  to  4  inches  in  thickness, 
which  are  called  Kriga  by  the  natives,  and  another  part  separates  as  a 
result  of  summer  surface  evaporation.  Samples  taken  by  Gauthier, 
and  analyzed,  showed  that  the  dry  salt  contained  95  per  cent,  pure 
sulphate.  According  to  a  calculation  of  Gauthier,  the  water  of  these 
lakes  should  yield  some  260,000  tons  of  the  salt.  A  company  has  been 
organized  in  Paris  to  work  this  deposit  systematically,  and  bring  it  to 
market. — Chem.  Indus. ^  iii,  p.  167. 
Analysis  of  Virginia  Rock  Salt. — According  to  B.  E.  Sloan,  the  rock- 
salt  of  Saltville,  Va.,  has  the  following  composition: 
NaCl,        .  ,           .             .             .             .             .  89-21 
Kcl,    ......  trace 
CaSo^2H20,             .....  4-86 
Fe,0„              .              .             .             .             .  0-84 
SiO,,          ......  4-53 
99'44 
Strontium,  barium  and  lithuim  were  absent. — Chem.  News^  vol.  40, 
p.  187. 
On  the  Action  of  Caustic  Soda  upon  Cast  Iron.— ^It  is  a  well-known  fact 
that  cast-iron  vessels  in  which  caustic  soda  has  been  repeatedly  fused 
are  gradually  attacked,  while  there  forms  a  porous,  spongy  mass. 
According  to  H.  Bruntk  and  C.  Graebe,  the  walls  of  such  vessels  in 
which  caustic  soda  has  been  heated  for  some  time  to  a  dull  red-heat, 
