Amseptf,'£9oarm"}  Gleanings  from  the  German  Journals.  445 
favorable  conditions  for  absorption.  It  has  the  formula  C6H4(OCH.J 
O  COC6H5.  For  its  preparation  crude  guaiacol  is  converted  into 
the  potassium  salt,  which  is  then  purified  by  crystallization  from 
alcohol ;  heated  with  the  calculated  quantity  of  benzoyl  chloride  the 
potassium-guaiacol  forms  benzosol  and  potassium  chloride.  After 
recrystallization  from  alcohol  it  forms  small  colorless  crystals,  melt- 
ing at  500,  almost  odor-  and  tasteless,  insoluble  in  water,  but  soluble 
in  alcohol  and  ether. — {Sudd.  Ap.  Ztg)  Apoth.  Ztg.,  1890,  389. 
The  specific  gravity  of  waxes,  resins  and  solid  fats  is  easily  and 
rapidly  determined  by  taking  a  cylindrical  piece  1-1-5  cm-  l°ng  anc* 
0*5  cm.  diameter  (made  by  pouring  the  melted  substance  into  a 
proper  mould),  weighing  it,  placing  it  in  a  dry,  narrow-necked  small 
flask  of  known  capacity  and  allowing  water  to  run  in  from  a  burette ; 
the  substance  should  lay  horizontally  in  the  flask,  so  that  when  the 
water  is  added  it  does  not  rise  into  the  neck  of  the  flask.  The 
weight  of  substance  divided  by  its  own  volume  of  water  gives  the 
desired  specific  gravity.  If  the  weight  of  the  substance  is  0  624, 
the  capacity  of  the  flask  25  cc,  and  after  introducing  the  fat  only 
24-3  cc.  water  are  required  to  fill  the  flask  up  to  the  same  point, 
then  =  0  89  I  is  the  specific  gravity.     The  temperature 
should  be  kept  at  I5°C.  during  the  determination. — Gawalowski 
{Oel  u.  Fett  Ind.)  Pharm.  Ztg.,  1890,  427. 
Detection  of  Nitrates  in  Iodide  of  Potassium. — o-i  gm.  potassium 
iodide  and  i-o  gm.  copper  sulphate  are  dissolved  in  10  cc.  water, 
heated  to  the  boiling  point,  sulphurous  acid  added  until  the  brown 
precipitate  becomes  white  and  filtered.  The  filtrate  can  then  be 
tested  for  nitrate  with  sulphuric  acid  and  ferrous  sulphate. — Schiir- 
holz,  Pharm.  Ztg,,  1890,  427. 
Honey. — Dr.  Oscar  Haenle,  after  long  series  of  experiments, 
announces  the  discovery  of  a  method  enabling  the  recognition  of  a 
pure  or  adulterated  honey.  It  is  based  upon  the  dialysis  of  the 
honey  diluted  with  water  and  after  some  hours,  testing  the  liquid  in 
the  dialyzer  by  polarized  light ;  no  matter  if  the  pure  honey  is 
dextro-  or  lsevogyre,  after  dialysis  it  is  found  that  the  liquid  remain- 
ing in  the  dialyzer  will  be  inactive  ;  adulterated  or  artificial  honey, 
on  the  other  hand,  always  will  leave  a  dextrogyre  liquid  in  the 
dialyzer,  no  matter  how  long  the  diffusion  is  allowed  to  proceed. 
The  rotatory  power  is  due  to  dextrin  or  dextrin-like  bodies  present 
