DETECTION  OF  ADULTERATED  ESSENTIAL  OILS.  387 
4th.  That  in  favorable  conditions  of  the  action  of  diastase  on 
starch,  as  much  as  50  per  cent,  of  glucose  may  be  obtained ; 
5th,  and  lastly.  That  it  has  not  been  possible  to  obtain  0-8791 
of  the  starch  used ;  but  the  maximum  product  has  not  exceeded 
0-5271. 
Acclirnatation  of  the  gum  tree. — M.  Bechu,  chief  gardener  of 
the  nursery  at  Biskra,  (Algeria,)  announces  that  he  has  succeeded 
in  completely  acclimating  in  that  establishment  the  Carica  papaya 
of  China,  and  the  Acacia  verecTc,  Arabica  and  nilotica,  producing 
gum  arabic,  which  was  sold  for  the  benefit  of  the  establishment. 
Tannaie  of  manganese. — M.  V.  F.  Marietta  (Jour,  de  Chim. 
Med.,)  considers  tannate  of  manganese  as  the  best  of  the  tonic, 
astringent,  and  antiseptic  salts,  which  he  finds  is  soluble,  con- 
trary to  the  usual  character  of  the  metallic  tannates.  The  author 
does  not  give  a  process  for  obtaining  this  tannate ;  nor  do  we 
find  it  noted  among  the  numerous  salts  of  tannic  acid  in  Gmelin's 
Chemistry.  We  presume  it  may  be  obtained  by  saturating  a 
solution  of  tannic  acid  with  hydrated  carbonate  of  manganese, 
(obtained  by  precipitating  the  sulphate  with  carbonate  of  soda,) 
and  evaporating  to  dryness.  M.  Marietta  recommends  a  series 
of  formulas  for  its  administration  and  application :  a  syrup  1, 
part  to  500;  ointment  1  part  to  160;  colyrium  1  grain  to  2 J 
ounces  of  rose  water  and  half  an  ounce  of  glycerin,  and  pills  one-- 
seventh  of  a  grain  in  each.  These  preparations  seem  very  weak 
compared  with  corresponding  preparations  of  iron. 
DETECTION  OF  THE  ADULTERATION  OF  ESSENTIAL  OILS 
WITH  OIL  OF  TURPENTINE  BY  THE  SACCHARIMETER. 
By  Dr.  Julius  Maier,  Assistant  in  the  School  of  Mines,  Columbia- Col- 
lege, New  York. 
The  essential  oils,  especially  the  expensive  ones,  are  mostly 
adulterated  with  oil  of  turpentine.  It  is  often  difficult  to  detect 
this  adulteration,  especially  when  the  adulterated  oil  gives  simi- 
lar reactions  with  oil  of  turpentine. 
With  the  saccharimeter  it  is  possible  not  only  to  detect  the 
adulteration  but  even  to  find  out  the  quantity  of  oil  of  turpen- 
tine mixed  with  the  other  essential  oils.    A  large  number  of  oils, 
22 
