GROWTH  AND  PREPARATION  OF  RHUBARB  IN  CHINA.  153 
preparation  of  ointments,  it  remains  to  answer  the  query  as  to 
the  best  plan  of  keeping  them  so  as  to  retard  the  tendenc  -  to 
oxidation. 
It  is  important  that  the  dispensing  jars  for  ointments  should 
be  of  material  impervious  to  fats.  Jars  of  French  or  German 
porcelain  answer  this  end,  and  ointments  kept  in  them  will  resist 
oxidation  for  a  much  longer  time  than  when  kept  in  the  ordinary 
Liverpool  or  earthenware,  which  is  of  a  porous  and  absorbent 
nature.  Whenever  the  least  tendency  to  oxidation  manifests 
itself,  the  jar  should  be  thoroughly  cleansed  by  means  of  strong 
soap  and  water,  or  a  diluted  solution  of  potassa  or  soda. 
The  position  selected  for  the  jars  in  the  shop,  should  be  one  in 
which  the  extremes  of  ordinary  temperature  are  avoided,  such  as 
a  dark  closet  against  a  brick  wall ;  near  the  floor  and  remote 
from  the  stove  or  heating  arrangement.  If  the  cellar  is  conve- 
nient of  access,  it  is  preferable  for  summer  use. 
By  attending  to  the  foregoing  precautions,  the  Pharmaceutist 
will  have  little  or  no  trouble  with  his  ointments  and  cerates,  and 
will  never  have  to  suffer  the  mortification  of  being  reminded  by 
a  customer  that  he  had  dispensed  a  rancid  preparation ;  such,  at 
least,  has  been  my  experience  in  a  practice  of  many  years. 
Baltimore,  June,  1865. 
Proc.  Am.  JPharm.  Assoc.,  1865. 
ON  THE  GROWTH  AND  PREPARATION  OF  RHUBARB  IN 
CHINA. 
By  Feed.  J.  Farre,  M.  D.  Cantab. 
To  the  Editor  of  the  Pharmaceutical  Journal : 
Sir, — It  has  often  occurred  to  me  that,  while  frequent  attempts 
have  been  made,  by  personal  inquiry  and  research,  to  discover 
the  source  and  exact  localities  of  the  Chinese  rhubarb  plant, 
which  have  only  resulted  in  deception  and  disappointment,  we 
have  in  great  measure  neglected  to  avail  ourselves  of  the  more 
reliable  information  contained  in  Chinese  books  and  manuscripts 
intended  for  the  use  and  instruction  of  the  Chinese  themselves. 
An  opportunity  of  obtaining  such  information  was  recently 
afforded  me  by  Mr.  Lockhart,  who  kindly  supplied  me  with 
