612  Gleanings  from  the  German  Journals.  { AmbJecU,ri8P^arm" 
Oil  of  Allium  sativum. — From  900  kilos  bulbs  only  800  gm.  oil 
were  obtained,  a  yield  of  0  09  per  cent.;  the  oil  has  a  yellow  color 
and  an  intense  characteristic  odor,  and  is  optically  inactive ;  sp.  gr. 
at  14-5°  C.  =  1-0525  ;  exposed  to  artificial  cold  a  very  small  quantity 
of  minute  crystals  separated  ;  upon  heating  to  I  500  C.  decomposi- 
tion ensues  with  the  evolution  of  very  offensive  gases.  By  fraction- 
ing  under  greatly  reduced  pressure  (16  mm.)  the  following  com- 
pounds were  obtained:  C6H12S2,  about  6  per  cent.,  sp.  gr.  1-0231  * 
at  1 50  C,  boiling  point  66-690  C.  at  16  mm.  pressure;  C6H10S2 
about  60  per  cent.,  sp.  gr.  1-0237  at  14-8°  C,  boiling  at  1 3 5— 1 39°  ; 
C6H10S3  boiling  at  112-1220,  16  mm.  pressure;  and  C6H10S4 
boiling  above  1 22°  C,  but  decomposing  during  distillation.  The 
compound  C6H10S2  purified  by  distillation  over  a  little  metallic 
potassium,  boils  at  78-800  C,  16  mm.  pressure;  it  gives  precipitates 
with  mercuric,  platinic  and  gold  chlorides.  The  oil  was  found  free 
from  allyl  sulphide  and  sesquiterpene,  which  have  been  claimed  to 
be  present.  Pure  allyl  sulphide  made  for  comparison  with  these 
fractions  is  a  colorless  oil,  sp.  gr.  0-8991,  at  160  C,  boiling  under  750 
mm.  pressure  at  136-1400  C,  under  15-5  mm.  at  36-380  C.  All 
of  the  sulphur  compounds  of  the  oil,  when  distilled  under  ordinary 
conditions,  suffer  decomposition. 
Oil  of  Allium  Cepa,  L. —  5,000  kilos  of  onions  only  yielded  233 
gm.  oil  0  005  per  cent.,  of  a  dark  brown  color,  mobile,  sp.  gr.  1-041 
at  8-7°  C;  laevogyre  ;  on  exposure  to  freezing  mixtures  separating 
a  small  quantity  of  lustrous  crystals.  Distilled  under  ordinary 
1  pressure  the  oil  decomposes  at  1600  C,  emitting  gases  of  very  offen- 
sive odor;  under  16  mm.  pressure  the  oil  can  readily  be  distilled. 
The  chief  constituent  is  C6H12S2,  boiling  at  75-830,  at  10  mm.;  specific 
gravity  1-0234  at  12°  C;  distillation  with  a  little  metallic  potassium 
yields  it  colorless,  with  larger  quantities  of  potassium  there  results 
colorless  C6H14S2,  boiling  at  68-690  C,  10  mm.  pressure;  by  oxida 
tion  it  yields  carbonic,  oxalic,  sulphuric,  propionic,  formic  and  acetic 
acids.  There  is  present  also  a  higher  sulphur  derivative,  which,  by 
reduction,  yields  C6H12S.  In  the  fraction  above  100°  C.  is  present 
a  sulphur  compound  probably  identical  with  a  constituent  of  asafce- 
tida  oil.  All  fractions  of  the  oil  give,  with  mercuric,  platinic  and 
gold  chlorides,  white,  resp.  yellow  precipitates.  Allyl  sulphide, 
hexenyl  sulphides  and  terpenes  were*  not  found  in  the  oil. — F.  W. 
Semmler,  Archiv  der  Pharm.,  1892,  434-438. 
