Am.  Jour.  Pharm. 
June,  1 918. 
Current  Literature. 
457 
paper  in  a  10  per  cent,  solution  of  sodium  carbonate.  If  much  nitrile 
is  present  the  paper  turns  blue,  but  with  smaller  quantities  a  red  or 
brownish-red  coloration  is  observed.  Very  small  quantities  of  nitrile 
can  be  detected  in  this  way. — S.  Dezani.  (Atti  R.  Acad.  Sci.  Torino* 
1917,  52,  826-833.)    From  The  Analyst. 
Preparation  of  Tannic  Acid,  Gallic  Acid,  and  Pyrogallol. — - 
Tannin  was  extracted  from  Japanese  gall  nuts  by  four  successive 
treatments  with  water  at  200  to  300  C,  and  the  residue  was  pressed. 
In  this  way  a  13  per  cent,  solution  of  tannin  containing  82  per  cent,  of 
the  theoretical  quantity  was  obtained.  Tannic  acid  was  prepared  by 
concentrating  the  extract  to  20  per  cent.,  extracting  it  with  half  its 
volume  of  ether,  and  evaporating  the  ethereal  extract.  About  75 
per  cent,  of  the  tannin  in  the  aqueous  extract  was  obtained.  For 
the  preparation  of  gallic  acid  the  residual  solution  from  the  tannic 
acid  preparation  was  concentrated  to  20  per  cent.,  and  treated  with 
15  to  20  per  cent,  (by  vol.)  of  sulphuric  acid  (66°  B.,  sp.  gr.  1.84), 
and  the  precipitated  black  mass  was  dissolved  in  water,  decolorized 
with  animal  charcoal,  and  finally  recrystallized  from  water.  The 
yield  was  62  per  cent,  of  the  tannin  contained  in  the  residual  solu- 
tion. Pyrogallol  was  prepared  by  heating  the  crude  gallic  acid  with 
about  3  times  its  volume  of  water  in  an  autoclave  at  2100  C.  The 
crude  product  (yield,  63.5  per  cent,  of  the  gallic  acid)  was  purified  by 
crystallization  from  pure  benzene. — M.  Mito.  Kogyo-Kwagaku- 
Zasshi  (/.  Chem.  Ind.,  Tokyo),  1917,  20,  720-736. 
Essential  Oil  of  Artemisia  annua. — The  work  of  Imada  on 
the  essential  oil  of  Artemisia  annua  has  been  extended.  The  oil  used 
had  the  following  characteristics:  Sp.  gr.  at  i6°/4°  C.  0.907798; 
optical  rotation,  16.190  ;  acid  value  1.82;  ester  value,  34.58;  ester 
value  after  acetylation,  63.54.  A  minute  quantity  of  an  oil  with  an 
odor  of  cumic  aldehyde  was  extracted  by  sodium  bisulphite  solution. 
The  remainder  was  steam-distilled,  yielding  an  oil  of  low  specific 
gravity.  The  brown  residue,  amounting  to  about  one  fifth  of  the 
original  oil,  distilled  between  1280  and  1820  C.  at  10  Mm.  pressure. 
The  fraction  of  the  light  oil  distilling  from  1760  to  181 0  C.  contained 
cineol.  The  fraction  distilling  from  181 0  to  1900  C.  contained  a 
ketone  yielding  a  semicarbazone  melting  at  960  C,  from  which 
concentrated  hydrochloric  acid  regenerated  the  pure  ketone,  having 
