xo'vimbeSoT'}    Recent  Literature  Relating  to  Pharmacy.  567 
or  Baeyer's  mixture  of  hydrogen  peroxide  and  sulphuric  acid  (Ber.y 
33,  124),  produce  a  brownish-red  powder  from  which  chloroform 
extracts  tetrahydroxy-methyl-anthraquinone,  C15H10O6.    L.  F.  K. 
CITRAL,  DETERMINATION  IN  OIL  OF  LEMON. 
E.  J.  Parry,  (Ch.  and  Dr.  57,  1 900)  replies  to  criticism  contained  in 
Schimmers  Semi.  Ann.  Rept.,  October  1900,  25,  on  his  method  for 
estimating  citral  in  lemon  oil  (Chem.  and  Drug.,  36,  376).  The 
first  objection  raised  is  that  as  high  as  1  per  cent,  of  citral  passes 
over  in  distillations  at  very  low  pressures,  this  loss  being  made  up  or 
exceeded  by  the  limonene  absorbed  by  the  cyanacetic  acid  solution. 
The  second  objection  raised  is  that  an  exact  reading  of  the  volume 
in  the  graduated  portion  of  a  Herschsohn's  flask  is  impossible.  In 
reply  to  the  first  criticism  the  writer  says  that  he  has  distilled  many 
samples  of  lemon  oil  at  a  pressure  of  10  millimetres  and  possibly 
below,  but  has  never  yet  found  any  portion  of  the  limonene  to  con- 
tain more  than  the  merest  trace  of  citral.  The  second  objection  is 
met  by  stating  that  the  reading  is  not  much  more  difficult  than  it 
is  in  several  other  absorption  processes.  He  reiterates  that  his 
method  gives  more  accurate  results  than  any  other  thus  far  pro- 
posed. L.  F.  K. 
MAIZE  IN  WHEATEN  FLOWER,  DETECTION  OF. 
E.  J.  Bevan  tested  [Analyst,  23,  316).  A.  C.  Wilson's  method 
and  found  it  to  give  satisfactory  results.  The  process  is  executed  as 
follows  :  mix  the  flour  with  clove  oil  and  examine  under  the  micro- 
scope with  a  one-fourth  or  one-eighth  objective.  The  hilum  of 
maize  starch  is  indicated  by  a  black  dot  or  star  while  wheat  and 
other  starches  are  practically  invisible. 
G.  Embrey  (Analyst,  23,  315)  was  unable  to  obtain  satisfactory 
results  with  Baumann's  quantitative  method  (Ztsc/i.  f.  Untersuch. 
Nahr.  u.  Gemussmittel  1899,  2,  2J).  He  therefore  offers  the  following 
modification  :  place  o-2  grammes  of  the  sample  into  a  1 5  cm.  by  2  cm. 
test  tube,  provided  with  a  paraffined  cork.  Add  20  cc.  of  aqueous 
potassium  hydroxide  (18  Gm.  per  litre),  shake  well  for  three 
minutes,  add  twelve  drops  of  ic  per  cent  hydrochloric  acid,  then 
introduce  the  tubes  into  a  centrifugal  and  at  whirl  600  revolutions 
per  minute.  Transfer  1  cc.  of  the  clear  liquid  into  a  Neesler  tube, 
dilute  to  50  cc;  add  1  cc.  of  iodine  solution  (I,  0-25  Gm.  KI,  1 
