I 2  6  Chemical  Notes.  { AmMJa°rTi?9arm* 
ration  of  zinc  and  nickel  that  is  said  to  exceed  in  exactness  all  other 
methods.  The  quite  dilute  solution  of  the  nitrates  or  sulphates  is 
made  ammoniacal,  and  then  acidified  with  pure  citric  acid.  After  the 
solution  has  become  perfectly  cold,  hydrogen  sulphide  gas  is  passed  in 
until  the  solution  smells  distinctly  of  it.  The  precipitated  sulphide  of 
zinc  will  contain  all  the  zinc.  After  standing  24  hours,  the  sulphide 
of  zinc  is  filtered  off  and  weighed  as  such.  The  filtrate,  concentrated 
down  to  a  small  bulk,  is  saturated  with  ammonia,  and  the  nickel  precipi- 
tated by  electrolysis.  For  this  latter  reason,  the  liquid  should  be  in 
nitric  acid  solution,  as  ammonium  chloride  hinders  the  electrolytic  pre- 
cipitation.—  Berichte,  XI,  p.  17 15. 
Applied  Chemistry. — Within  the  last  year  or  two,  several  improve- 
ments have  been  introduced  by  the  French  in  the  working  of  the 
molasses  residues  from  the  beet-root  sugar  manufacture.  These  residues, 
after  treatment  for  the  extraction  of  the  potash  salts,  are  now  sub- 
mitted to  dry  distillation,  and  several  most  valuable  products  are 
obtained. 
In  the  distillation  gases  and  tar  are  formed,  together  with  much  con- 
densed water.  The  latter  alone  is  important.  From  it  is  obtained 
ammonium  sulphate,  methyl  alcohol  and  large  amounts  of  crude  tri- 
methylamin  salts.  The  methyl  alcohol  is  all  sold  for  use  in  the 
manufacture  of  anilin  colors,  while  the  tri-methylamin  salts,  by  a  new 
process  of  Vincent,  the  chief  promoter  of  this  industry,  are  decom- 
posed with  the  production  of  methyl  chloride,  an  extremely  volatile 
liquid,  boiling  at  23°C.  This  is  used  in  the  formation  of  artificial  ice, 
and  also  in  the  manufacture  of  anilin  colors  containing  methyl.  This 
fine  utilization  of  what  was  long  regarded  as  purely  a  waste  product 
was  considered  as  one  of  the  most  striking  improvements  in  applied 
chemistry  shown  at  the  late  Paris  exhibition. — Dingler's  'Journal,  230, 
p.  263. 
Petroleum  Soaps. — These  soaps,  lately  brought  on  the  market,  are 
formed  by  adding  petroleum,  with  which  has  been  mixed  a  definite  quan- 
tity of  Carnauba  wax,  to  the  soap-making  materials.  If  these  products  are 
submitted  to  distillation,  the  petroleum  distills  off  unchanged,  and  the 
soap  remains  behind,  also  unchanged.  The  soaps  dissolve  entirely  in 
water,  neither  the  petroleum  nor  carnauba  wax  separating  out  even  as 
an  emulsion.  A.  Livache  has  examined  the  question  of  the  effect  of 
the  admixture  of  carnauba  wax  upon  the  petroleum.    This  wax  is 
