Am.  Jour.  Pha  m.  ) 
Sept.,  1877.  / 
Japan  Vegetable  Wax, 
451 
worthy  a  portion  of  the  rations  of  the  German  soldiery.  It  has  been 
recommended  as  a  substitute  for  rubber  for  numerous  purposes  in  hos- 
pitals, etc. 
It  has  been  found  to  perfectly  answer  the  purpose  of  parchment  in 
the  process  of  separating  mixtures  of  various  substances  by  the  method 
of  analysis  known  as  dialysis,  a  method  devised  by  the  English  chemist 
Graham,  for  the  separation  of  crystallizable  from  amorphous  substances. 
This  analytical  method  has  come  to  be  recognized  as  of  the  greatest 
importance.  It  was  formerly  a  matter  of  the  greatest  difficulty  to  effect 
the  perfect  separation  of  many  of  the  crystallizable  substances  of  the 
vegetable  kingdom  (many  of  which  are  indispensable  in  medicine)  from 
the  gummy  and  other  amorphous  substances  naturally  associated  with 
them,  as  the  presence  of  the  latter  obstinately  hinders  the  operation. 
It  is  only  necessary  now  to  bring  the  vegetable  decoction  upon  a 
diaphragm  of  parchment  paper,  and  to  float  the  same  upon  a  surface  of 
distilled  water,  when  the  crystallizable  materials  present  will  find  their 
way  through  the  diaphragm  into  the  water,  while  the  amorphous  ingre- 
dients are  retained  above,  being  unable  to  pass  the  membrane. 
By  this  simple  means  the  rapid  and  perfect  separation  of  these  two 
classes  of  substances  is  rendered  possible,  and  the  pharmaceutical 
chemist  is  provided  with  an  apparatus  of  incalculable  value.  It  is  obvi- 
ous, without  entering  into  additional  particulars,  that  the  value  of  the 
dialytical  method  is  not  confined  to  the  preparation  of  pure  crystalliz- 
able substances  of  animal  or  vegetable  nature,  but  that  its  utility  extends 
in  other  directions.  So,  for  example,  it  has  been  employed  with  great 
success  in  medico-legal  examinations  for  the  detection  of  cases  of  sup- 
posed poisoning,  the  dialyser  affording  a  simple  and  rapid  means  of 
separating  the  crystallizable  arsenic  salts  and  the  like  from  the  mass  of 
organic  matter.  It  is  only  of  late  that  the  admirable  qualities  of  parch- 
ment paper  have  begun  to  attract  attention,  and  we  may  safely  predict 
that  its  utility  has  by  no  means  been  yet  exhausted. — Polytech.  Review, 
No.  22.  
JAPAN  VEGETABLE  WAX. 
The  most  important  article  in  Japan  for  illuminating  purposes  is  the 
candle  made  of  vegetable  wax,  which  is  mostly  composed  of  palmitin. 
It  is  produced  from  the  fruit  of  several  trees  belonging  to  the  genus 
Rhus,  amongst  which  the  Rhus  succedanea  is  the  most  important,  and  is 
