588 
Progress  in  Pharmacy. 
(Am.  Jour.  Pharm. 
\  November,  1904. 
palmatum,  gave  but  2-8  per  cent.,  the  drug  obtained  from  Rheum 
officinale  2  per  cent.,  and  Rheum  collinianum  1-8  per  cent.  It  will 
readily  be  seen  that  Rheum  palmatum  is  the  only  variety  that  at  all 
approximates  Chinese  rhubarb  in  strength,  and  Tschirch  therefore 
strongly  recommends  the  raising  of  this  variety  alone  for  medicinal 
purposes.  From  a  recent  trade  report  by  Caesar  and  Loretz,  Halle 
a.  d.  S.,  it  appears  that  there  are  at  least  three  distinct  types  of  Chi- 
nese rhubarb  : 
(1)  Shensi  rhubarb;  this  occurs  in  full,  flat  or  round  pieces,  hav- 
ing a  bright  red  color,  not  fibrous,  with  a  distinctive,  mild  and  not 
disagreeable,  odor  and  a  slightly  aromatic  bitter  taste.  Shensi  or 
shansi  rhubarb  is  considered  the  more  valuable  variety,  and  always 
commands  a  much  higher  price  than  either  of  the  others. 
(2)  Canton  rhubarb ;  this  usually  consists  of  round  or  flattish 
round  pieces  that  have  a  tough,  fibrous  and  more  sponge-like  struc- 
ture and  pale  red  color.  Canton  rhubarb  has  a  distinctly  empyreu- 
matic  odor  and  a  distinctly  bitter  and  peculiarly  astringent  taste. 
(3)  Shanghai  rhubarb ;  flat,  usually  thinner  pieces,  partially 
fibrous,  tough  and  usually  of  a  firmer  and  a  denser  structure,  yel- 
lowish red  color,  more  distinctly  empyreumatic  odor  and  a  pecu- 
liarly disagreeable  and  persistently  bitter  mucilaginous  taste.  [Sud. 
Deut.  Apoth.  Zeit.,  1904,  page  590.) 
Refractive  Index  of  Clove  Oil. — W.  H.  Simmons  believes  that 
there  can  be  no  doubt  that  the  refractive  index  of  clove  oil  is  an 
important  and  useful  factor,  indicating  as  it  does  the  approximate 
content  of  eugenol.  It  is  not  safe  to  base  an  opinion  on  the  refrac- 
tive index  alone,  particularly  in  cases  in  which  the  genuineness  of 
the  sample  cannot  be  guaranteed.  (Chem.  News,  through  Phar. 
Jour.,  1904,  page  450.) 
Detection  of  Powdered  Gtim  Acacia  in  Powdered  Tragacanth. — E. 
Payet  finds  that  tragacanth  does  not,  like  acacia,  contain  an  active 
oxydase,  which  acts  on  guaiacol  in  aqueous  solution,  in  the  presence 
of  hydrogen  peroxide.  He  proposes  to  take  advantage  of  this  fact 
in  the  following  test :  If  a  1-30  solution  of  the  suspected  gum  in 
cold  water  is  mixed  with  an  equal  volume  of  a  I  per  cent,  guiacol 
solution  in  water,  and  a  drop  of  hydrogen  peroxide  added,  the 
mixture,  if  acacia  be  present,  will  soon  become  brown,  but  if  the 
tragacanth  be  pure,  remain  unchanged.  (Phar.  Jour.,  1904,  page 
453,  from  Repertoire  de  Phar.) 
