VARIETIES. 
471 
On  White  or  Imperial  Rhubarb.  By  Dr.  G.  Walpers. — In  all  works  on 
Pharmacology  there  occurs  a  somewhat  vague  account  of  a  very  superior 
kind  of  rhubarb,  said  to  be  collected  for  the  sole  and  particular  use  of  the 
Imperial  Court  of  St.  Petersburg,  and  distinguished  by  the  name  of  White  or 
Imperial  Rhubarb  [Radix  Rhei  alba  seu  imperialis.)  It  is  described  as  a  rhu- 
barb root  in  which  the  white  portion  so  far  predominates,  that  only  a  few  red 
streaks  are  perceptible  upon  the  surface  of  a  transverse  section.  No  one, 
however,  is  from  personal  knowledge  acquainted  with  this  species  of  rhu- 
barb. In  order  to  put  an  end  to  these  doubts,  I  some  time  «ince  addressed  a 
letter  to  Mr.  Buchner,  chief  Apothecary  to  the  Imperial  Court,  begging  him 
for  a  small  specimen  of  this  11  Imperial  Rhubarb"  for  my  pharmacological 
collection,  or  should  the  communication  of  this  precious  drug  be  inadmissible, 
that  I  might  at  least  have  an  authentic  description  of  it.  Mr.  Buchner 
replied  to  this  request  with  the  utmost  promptitude,  informing  me  that,  after 
having  instituted  the  most  careful  inquiries,  it  appeared  that  no  such  species 
of  rhubarb  had  at  anytime  been  imported  for  the  Imperial  family;  that  it  had 
never  occurred  in  commerce;  and,  finally,  that  in  neither  any  public  or 
private  collection  in  St.  Petersburg  was  there  to  be  found  a  specimen  of  this 
(consequently  mythical)  root. — Pharm.  Journ.} from  Bonplandia.  March,  1853. 
[It  was  the  Russian  traveller  Pallas  who  first  drew  attention  to  the  so-called 
White  Rhubarb.  We  extract  from  his  works  the  passage  relating  to  it:  a  J'ai 
vu  pendant  mon  sejour  a  Kiakta  des  petits  morceaux  de  rhubarbe  blancs 
comme  du  lait.  Elle  est  douce  au  gout,  et  a  les  memes  proprietes  que  celle 
de  la  meilleure  qualite.  L'apothicaire  se  proposoit  de  trier  tous  ces  mor- 
ceaux, et  de  les  envoyer  sepaiement  a  Petersbourg  pour  la  pharmacie  de  la 
Cour.'; — Voyages  de  M,  P.  S.  Pallas,  en  differ entes  Provinces  de  V Empire  de 
Russie,  et  dans  VAsie  Septe?itrionale,  traduits  de  VAllemand.  Paris,  4to,  1793, 
tome  iv.,  p.  219. — Ed.  Ph.Journ."] 
Ointment  of  Mucuna  Pruriens  as  a  counter-irritant. — M.  Blatin  proposes 
[Revue  Medico-Chirurgicale,  Jan.  1853)  the  substitution  of  mucuna  pruriens 
(cowhage)  for  tartar-emetic  or  croton-oil,  as  the  active  ingredient  of  oint- 
ments intended  to  act  as  cutaneous  irritants.  The  proportions  are,  seven 
grains  and  a  half  of  the  hairs  of  cowhage  to  an  ounce  of  lard.  The  oint- 
ment must  be  rubbed  in  from  ten  to  twenty  minutes  ;  seven  or  eight  grains 
are  usually  sufficient.  The  immediate  effect  is  the  production  of  a  sensa- 
tion resembling  stinging  with  nettles ;  but  the  burning  sensation  and  the 
itching  diminish  during  the  friction,  and  entirely  pass  off  in  less  than  half 
an  hour.  The  skin  generally  becomes  covered  with  white  flat  papulae, 
which  soon  disappear,  leaving  a  sensation  of  heat.  The  effect  is  due  to  the 
mechanical  irritation  of  the  hairs.  This  system  of  counter-irritation  has, 
we  are  told,  produced  no  inconvenience  ;  children  bear  it  easily.  The  indi- 
cations for  its  employment  are  the  same  as  for  the  use  of  tartar-emetic  or 
croton-oil  ointment. 
M.  Blatin  believes  cowhage  ointment  to  be  a  good  medium  for  the  en- 
