Am*  o°ct.?i8£arm'}  Gleanings  from  the  German  Journals.  489 
gives  a  violet-blue  coloration ;  similar  colorations  are  obtained  with 
bichromate  of  potassium  and  ferric  salts  and  sulphuric  acid. — Journ. 
Pharm.  Els.-Lothr.,  J  890,  206. 
Artificial  musk  has  the  chemical  name,  trinitro-isobutyltoluol  and 
formula  C6H(CH3)(C4H9)  (N02)3.  It  is  made  by  slowly  adding  pure 
isobutyltoluol  (b.  p.  1 85 0  C)  to  five  times  its  weight  of  a  mixture 
containing  one  part  fuming  nitric  acid  sp.  gr.  1-5  and  two  parts  fif- 
teen per  cent,  fuming  sulphuric  acid  ;  the  mixture  must  be  chilled 
to  prevent  rise  in  temperature.  After  standing  for  some  time  it  is 
heated  for  twenty-four  hours  in  a  waterbath ;  addition  of  water  pre- 
cipitates a  nitro-product  which  must  again  be  nitrated  to  yield  a 
pure  trinitro  derivative,  this  after  precipitation  by  water  is  recrystal- 
lized  from  alcohol.  It  forms  yellowish-white  needles,  melting  at  96- 
97°C;  insoluble  in  water,  it  is  easily  soluble  in  alcohol,  ether  and 
chloroform.  Physiological  experiments  by  Dr.  Hepp,  of  Mulhausen, 
made  with  animals  prove  its  non-poisonous  character.  The  mono- 
and  di-nitro  derivatives  of  isobutyltoluol  have  an  unpleasant  odor 
not  at  all  resembling  musk.  Trinitro-isobutylxylol  has  an  odor  of 
musk  but  not  at  all  comparable  with  the  toluol  derivative. — Dr.  A. 
Baur,  Chem.  Ztg.,  1890,  1093. 
Preparation  of  oxygen. — Dr.  George  Kassner  noticed  that  barium 
peroxide  brought  in  contact  with  potassium  ferricyanide  in  presence 
of  a  little  water  liberated  a  gas  found  to  be  almost  pure  oxygen. 
The  evolution  of  gas  is  attended  with  a  change  of  color,  the  ferri- 
cyanide being  changed  to  ferrocyanide ;  if  sufficient  water  is  used, 
the  product  remaining  in  the  generator  dissolves  completely,  except- 
ing the  impurities  of  the  Ba02.  The  reaction  for  this  process  is 
given :  Ba02  +  K6Fe2(CN)12  =  Ba(K3Fe(CN)6)2  +  02.—(Ztschr.  f 
angew.  Chem.)  Apoth.  Ztg.,  1890,  484. 
Sterilizing  of  drinking  water. — Various  chemicals  have  been  pro- 
posed for  this  purpose,  of  which  ferric  chloride,  alum,  tannin  and  potas- 
sium permanganate  have  been  used,  but  it  was  found  that  these  to  be 
effective  had  to  be  used  in  quantity  which  imparted  an  unpleasant  taste 
to  the  water.  Recently  Hettinga  Tromp  proposed  hydrogen  perox- 
ide as  the  ideal  substance  to  sterilize  water  as  it  imparted  neither 
odor  nor  taste  and  was  harmless  and  efficient ;  one  part  was  added 
to  3,000 — 10,000  parts  of  water.  Dr.  Altchoefer  confirms  the  effi- 
ciency of  hydrogen  peroxide  but  asserts  that  1  :  1000  must  be  used  ; 
after  24  hours'  standing  the  water  microbes  as  well  as  pathogenic 
