224  GLEANINGS  FROM  THE  FRENCH  JOURNALS. 
it  with  a  hot  solution  of  nitrate  of  baryta.  The  sulphate  of  ba- 
ryta is  then  removed  by  filtration  through  asbestos,  and  the 
clear  solution  of  nitrate  of  silver  evaporated  and  crystallized. — 
Jour,  de  Ohimie  Med.,  Janv.  1860. 
Root  of  Hibiscus  esculentus,  or  Okra. — G-.  Delia  Sudda  states 
(Rupert,  de  Pharm.,  Janv.  1860)  that  this  root  is  largely  em- 
ployed at  Constantinople  and  other  portions  of  the  East,  as  a 
demulcent,  in  the  same  way  as  althaea  root  is  used  in  Europe, 
and  seems  to  possess  much  the  same  properties.  This  vegetable 
originated  in  the  East  Indies,  then  extended  into  other  parts  of 
the  world,  its  fruit  being,  as  is  well  known,  much  used  as  an  ar- 
ticle of  diet  for  soups. 
In  the  neighborhood  of  Constantinople  and  in  the  interior,  its 
culture  is  conducted  on  a  large  scale,  entire  plains  and  vallies 
being  covered  with  it,  in  fields  requiring  but  little  care  or  ma- 
nure. The  size  attained  by  the  fruit  varies  much,  being  from  an 
inch  to  ten  or  twelve  inches.  The  recent  roots  have  a  length  of 
from  18  to  24  inches,  with  a  diameter  of  half  an  inch  to  an  inch 
and  a  half ;  yellowish  white  epidermis,  removed  easily  by  rubbing, 
and  yields  by  pressure  a  thick  mucilaginous  juice  in  great  abun- 
dance. In  equal  quantity  compared  with  the  althaea  root,  it 
yields  double  the  quantity  of  mucilage,  and  free  from  the  odor 
of  the  althaea.  Its  powder  is  beautifully  white,  and  superior  in 
all  respects  to  that  of  the  marshmallow. 
Easy  means  of  Silvering  Copper  and  Brass  Surfaces. — M. 
Boudier  recommends  a  powder  composed  of  12  parts  of  cyan- 
ide of  potassium,  6  parts  of  nitrate  of  silver,  and  thirty  parts  of 
prepared  chalk.  Rub  the  surface  to  be  silvered  with  a  moist  rag 
which  has  been  dipped  in  this  powder,  and  a  deposition  of  silver 
takes  place  which  is  strongly  adherent,  and  may  be  used  advan- 
tageously to  apply  to  some  utensils  before  bringing  them  in  con- 
tact with  acid  fruits. — Repert.  de  Pharm.,  Janv.  1860. 
Adulteration  of  Rhubarb. — In  France  as  well  as  in  England 
the  powder  of  Turkey  rhubarb,  it  seems,  is  extensively  adulte- 
rated with  that  of  the  home  grown  root.  M.  E.  Billot  gives  a 
method  of  detecting  this  adulteration,  which,  if  successful,  is  cer- 
