458 
Current  Literature. 
Am.  Tour.  Pharm. 
June,  1 918. 
the  formula  C  10,  H  16,  O,  boiling  at  7i°-/5°  C.  at  11  Mm.,  and  at 
182 0  at  760  Mm.  Its  sp.  gr.  at  14V40  C.  was  0.8906,  refractive  in- 
dex 1.4695  at  1 8. 50  C,  and  it  was  optically  inactive. 
Catalytic  reduction  of  hydrogen  yielded  a  tetrahydroketone, 
forming  a  semicarbazone  melting  at  I34°-I35°  C.  The  pure  tetra- 
hydroartemisia-ketone  boiled  at  73 0  C.  at  15  Mm.3  and  at  1730 
C.  at  760  Mm.;  sp.  gr.  at  19.5V40  C.,  0.8262,  and  refractive  index, 
1.42425.  The  higher-boiling  fractions  of  the  oil  (i9o°-2io°  C.) 
yielded  a  semicarbazone  melting  at  236^237 0  C,  which  when  treated 
with  dilute  sulphuric  acid  yielded  a  solid  ketone,  m.  pt.  175 0  C,  with 
all  the  properties  of  1-camphor. — Asahina  and  Yoshitomi.  (/. 
Pkarm.  Soc.  Japan,  1917.  Xo.  424,  1.  Perf.  and  Esscnt.  Oil  Rec., 
I9I7.«  8,  353-354.  From  Journal  of  the  Society  of  Chemical  In- 
dustry, February  15.  1918. 
Determination  of  Metallic  Iron  in  Ferrum  Reductum. — 
The  author  finds  that  the  simple  method  described  by  Winkler 
(Z.  angew.  Chem.}  1917,  64)  is  not  trustworthy,  since  the  increase 
in  weight  of  the  sample  does  not  attain  a  constant  value  even  after 
the  ignition  in  air  for  15-20  minutes  has  been  repeated  five  or  ten 
times  :  moreover,  by  the  prolonged  ignition  the  tri ferric  tetroxide 
originally  present  in  the  ferrum  reductum  is  partially  converted  into 
ferric  oxide,  with  the  result  that  the  percentage  of  metallic  iron 
found  is  too  high.  The  author  has  examined  the  official  methods 
adopted  in  different  countries.  He  recommends  that  in  addition  to 
the  total  iron,  the  metallic  iron  be  estimated  by  Merck's  mercuric 
chloride  method  :  25  Cc.  of  the  filtrate  should  be  used,  the  solution 
of  potassium  permanganate  should  be  dilute  (2-2.5  Gm.  per  liter), 
and  the  confirmatory  iodometric  estimation  may  be  omitted.  The 
author  has  examined  a  method  in  which  bromine  instead  of  iodine 
is  used  for  the  solution  and  estimation  of  the  iron.  The  method  fails 
on  account  of  the  unavoidable  loss  of  bromine  vapor  during  the  esti- 
mation.— A.  Eberhard.  (Arch.  Pharm.,  1917,  255,  357-381.) 
From  Journal  of  the  Society  of  Chemical  Industry,  January  31, 
1918. 
Detection  and  Estimation  of  Zinc  in  Water. — The  film  test 
will  detect  1  part  of  zinc  in  200,000  if  it  is  present  as  bicarbonate, 
but  where  it  is  present  in  other  combinations  the  test  fails.  The 
opalescence  test  with  ammonium  sulphide  as  reagent  will  detect  1 
part  in  100.000,  and  with  ferrocyanide  as  reagent  may  detect  1  part 
