448  A  few  Species  of  Rhubarb.  { """blpTxfst""- 
until  it  melts,  when  the  mixture  is  shaken  gently.  The  aqueous  liquid 
becomes  slightly  cloudy  if  the  wax  is  pure  beeswax,  but  never  becomes 
milky.  When  set  aside  for  cooling  the  layer  of  wax  collects  on  the 
surface  of  the  liquid,  leaving  the  latter  almost  clear,  or  only  slightly 
turbid  or  half  translucent.  If  it  becomes  milky  immediately  and 
remains  translucent  and  milky  even  after  cooling,  either  Japan  vegetable 
wax  or  stearin  are  present.  Resin  and  Brazil  vegetable  wax  act 
like  pure  beeswax  in  this  test. 
4.  Soda  test.  Mix  in  a  test  tube  a  piece  of  wax,  the  size  of  a  bean, 
and  6  to  7  cc.  sodium  carbonate  solution  (i  salt,  6  water).  Heat  in 
such  a  manner  that  the  upper  layer  of  the  liquid  is  heated  without 
agitation  until  the  wax  is  melted.  If  much  froth  is  noticed  at  the 
wax  layer  stearic  acid  is  probably  present.  The  whole  is  then  heated 
to  the  boiling  point.  If  the  liquid  becomes  milky,  milky-yellowish  or 
milky  white,  Japan  wax  or  stearic  acid  is  present.  In  this  case  the 
aqueous  liquid  remains  milky,  even  after  cooling;  in  case  Japan  wax 
is  present,  more  or  less  pasty,  or  even  stiff,  while  if  stearic  acid  is 
present  the  milky  layer  is  usually  liquid,  and  often  appears  crossed  by 
clear  layers.  The  wax  layer  on  the  surface  is  usually  brittle  and  not 
hard. 
Pure  beeswax  appears  hard  after  cooling  slowly,  and  the  aqueous 
layer  is  cloudy,  but  not  milky,  frequently  semi-translucent  and  entirely 
liquid. 
If  the  beeswax  contains  pine  resin  this  test  will  cause  an  entire 
separation  of  the  resin.  Instead  of  merely  heating  to  the  boiling  point 
allow  to  boil  for  one  minute  and  then  to  cool  gradually.  The  mass 
then  consists  of  three  layers,  an  upper  hard  wax  layer,  a  liquid  slightly 
turbid  middle  aqueous  layer,  and  a  loose  or  flocculent  resin  layer  on 
the  bottom.  The  resin  can  then,  of  course,  be  readily  determined 
quantitatively. 
A  FEW  SPECIES  OF  RHUBARB. 
By  H.  v.  Schlagintweit. 
Translated  and  condensed  from  "  Ztschr.  d.  Allg.  Oest.  Apoth.,"  Ver.,  April  lo, 
1880,  p.  170,  by  Louis  von  Cotzhatjsen,  Ph.G. 
The  cultivation  of  rhubarb  in  India  was  hitherto  unsuccessful.  The 
so-called  India  rhubarb"  of  commerce  consists  of  roots  cultivated  in 
the  neighboring  districts  of  High  Asia.     There  is  as  little  of  this  in 
