33 2  Gleanings  from  the  German  Journals.  {Am'j^c,'w^xm' 
Fette  u.  Wachsarten.)  Azelaic  acid  is  a  secondary  oxidation  pro- 
duct of  oleic,  linolic  and  the  linolenic  acids. 
In  many  cases  the  above  method  may  be  made  even  more  expe- 
ditious, as  in  cases  where  it  is  only  a  question  if  certain  drying  acids 
like  linolic  acid  are  present  in  a  non-drying  oil;  10  gm.  are  oxi- 
dized with  io  gm.  permanganate  of  potassium  as  stated,  the 
alkaline  filtrate  acidulated  with  HC1  gives  the  precipitate  of  oxidized 
and  non-oxidized  fatty  acids  which  are  not  treated  with  petroleum 
ether,  but  boiled  with  about  one  litre  of  water  and  filtered  without 
cooling  ;  the  filtrate  is  made  faintly  alkaline,  evaporated  to  100-150 
cc,  transferred  while  still  warm  to  a  separatory  funnel,  acidified  with 
HC1,  allowed  to  become  cold  and  agitated  with  ether,  which  will 
dissolve  the  azelaic  acid  and  any  fatty  acids  passing  through  the 
filter  so  that  no  solids  are  suspended  in  the  ethereal  solution  of  the 
fat  or  oil  containing  only  oleic  acid  as  the  fluid  acid;  on  the  other 
hand,  if  only  small  quantities  of  linolic  acid  are  present  in  the  fat  or 
oil  examined  white  flakes  of  sativic  acid  will  be  seen  suspended  in 
the  lower  part  of  the  ethereal  layer. 
Butter  and  tallow  examined  in  this  manner  gave  no  evidence  of 
sativic  acid  and  hence  contained  no  linolic  acid  ;  cotton-seed  oil 
and  lard  were  shown  to  contain  linolic  acid,  thus  offering  in  the  case 
of  lard  some  explanation  of  the  discrepancies  in  the  iodine  figure. 
Dioxy stearic  acid  isolated  from  tallow,  butter  and  lard  and  identified 
by  its  combining  weight  was  found  to  melt  at  124-1260  C;  sativic 
acid  obtained  from  cotton-seed  oil  and  lard  and  identified  by  ulti- 
mate analysis  melted  at  1520  C;  Hazura  gives  as  the  melting  points 
of  these  two  acids  1370,  and  1 73 °,  respectively. — Chemiker  Ztg.^ 
1893,  610. 
Test  for  monatomic  alcohols. — 1-2  cc.  of  an  aqueous  methyl 
violet  solution  (0*5  in  iooo-o)  are  added  with  0-5-1  cc.  of  an 
alkaline  polysulphide  solution  to  2-3  cc.  of  the  liquid  to  be  tested 
tor  monatomic  alcohols ;  in  the  presence  of  the  latter,  the  test 
becomes  cherry  or  violet-red  in  color  without  becoming  turbid  and 
after  prolonged  standing  the  colorations  may  change.  In  the 
absence  of  this  class  of  alcohols  the  test  becomes  greenish  blue, 
separating  after  some  time  reddish-violet  flakes,  the  liquid  itself 
becoming  yellow.  Methyl,  ethyl,  normal  and  iso-propyl  alcohols 
give  a  cherry  red  color,  while  tertiary-  and  iso-butyl  alcohols,  iso- 
butyl-carbinol  and  allyl  alcohol  give  a  violet-red  color.    The  test 
