AMMi7iii8fl74RM  }  Gleanings  from  the  European  Journals.  235 
and  but  little  glucose  enters  into  solution.  The  variable  composition 
of  commercial  tannin  is,  therefore,  due  to  the  menstruum  employed 
in  its  preparation,  and  the  different  amounts  of  glucose  obtained  by 
various  investigators  are  thereby  satisfactorily  explained. — Annalen  d. 
Chem.  und  Pharm.  clxx,  43-88. 
Buchu  Leaves. — Professor  Fluckiger  obtained  from  the  volatile  oil 
of  Barosma  betulina,  by  exposure  to  cold,  a  stearopten,  crystallizing 
in  handsome  needles  and  resembling  the  stearopten  of  peppermint  oil ; 
the  elseopten,  rectified  over  sodium,  has  the  composition  C10H16O. 
The  aqueous  infusion  of  the  leaves  contains,  besides  mucilage,  a  body 
allied  to  quercitrin  or  rutin,  which  is  not  altered  by  ferrous  salts,  but 
•colored  brown-greenish  by  ferric  chloride.  The  mucilage  is  contained 
in  a  thin  layer  of  cells  (collenchyma)  situated  immediately  beneath 
the  epidermis  of  the  upper  surface.  This  layer  expands  very  consider- 
ably if  the  cross-section  of  a  leaf  is  immersed  in  glycerin,  or  more 
rapidly  in  water.  The  expanded  collenchyma  has  one-half  the  thick- 
ness of  the  leaf  of  Barosma  betulina ;  but  fully  two-thirds  of  the 
thickness  of  the  leaves  of  B.  crenulata,  B.  serratifolia  and  Empleurum 
serratifolium,  all  of  which  are  much  thinner  than  those  of  the  first- 
named  species.— 2V.  Repert.  f.  Pharm.,  1874,  p.  102-105. 
Adulteration  of  Volatile  Oil  of  Mustard.— Dr.  Hager  (Pharm. 
Central  Halle)  has  obtained  a  sample  of  this  oil  which  was  heavier 
than  water,  and  was  probably  adulterated  with  oil  of  gaultheria,  for 
its  solution  in  alcohol  was  colored  violet  by  ferric  chloride. 
Balsam  of  Tolu. — P.  Carles  obtained  the  acid  from  soft  and  hard 
tolu  balsam  by  digesting  it  with  water  and  cooling.  After  recrystal- 
lizing  from  alcohol  and  water,  the  nature  of  the  acid  was  determined 
volumetrically  and  the  figures  147*85  and  148*40  were  obtained  for 
the  acid  as  obtained  from  hard  and  soft  tolu  respectively.  The  combin- 
ing weight  of  benzoic  acid,  C7H602,  being  122,  and  that  of  cinnamic 
acid,  C9H802,  =  148,  the  author  concludes  that  tolu  balsam  contains 
only  cinnamic,  but  no  benzoic  acid. — Journ.  de  Pharm.  et  de  Chim., 
1874,  Feb.,  112. 
Iodine  Caustic  is  prepared  by  Bieseberg  by  dissolving  four  grams 
of  iodine  in  eight  grams  of  glycerin.  It  is  used  in  lupus  by  applying 
it  once  every  other  day,  and  covering  the  parts  with  gutta  percha. 
This  treatment  is  continued  for  several  weeks. — Ibid.  140. 
