Am' £Lay*\maTm'} ^nah/sts  of  True  and  Commercial  Pareira.  255 
For  purposes  of  ordinary  examination  it  is  only  necessary  to  make 
a  clean  section  of  the  drug  with  a  sharp  knife  or  razor,  and  examine 
the  cut  surface  with  a  good  lens  ;  but  when  a  thin  section  is  required 
for  more  detailed  examination  under  the  microscope,  a  piece  should 
be  soaked  in  water  for  a  day  or  two.  It  is  then  comparatively  easy 
to  make  a  thin  section,  which  should  be  stained  in  the  usual  manner. 
TRUE  AND  COMMERCIAL  PAREIRA.1 
By  F.  A.  Ringer  and  E.  Brooke. 
Some  time  ago  Mr.  E.  M.  Holmes,  the  Curator  of  the  Society's 
museum,  informed  us  that  he  had  a  sample  of  a  substitute  of  pareira 
which  had  recently  come  into  the  market  in  large  quantities,  its 
botanical  origin  being  unknown.  At  his  recommendation  we  deter- 
mined to  investigate  the  chemical  characters  of  this  root,  and  com- 
pare the  results  with  those  obtained  from  the  roots  of  Chondoden- 
dron  tomentosum. 
Examining  these  preliminarily  we  noticed  that  the  genuine  root 
cut  like  very  hard  wax,  whereas  the  spurious  one  when  cut  crum- 
bled into  pieces.  The  powder  of  the  true  pareira  brava  is  also 
much  lighter  in  color,  but  heavier  bulk  for  bulk  than  the  sub- 
stitute. 
The  cooled  aqueous  decoction  of  the  latter  drug  will  not  give 
any  coloration  when  treated  with  iodine,  and,  therefore,  does  not 
answer  the  Pharmacopoeia  description  in  this  respect. 
The  amount  of  moisture  in  the  two  roots  was  practically  the 
same,  both  drugs  being  dried  at  a  temperature  of  no°  C.  In  the 
case  of  chondodendron  it  amounted  to  9  30  per  cent.,  and  in  the 
substitute  to  8-99  per  cent,  of  the  whole  weight. 
The  total  ash  was  next  estimated,  and  was  found  to  be  4  29  per 
cent,  in  the  original  drug,  and  in  the  substitute  1-32  per  cent. 
When  chemically  and  spectroscopically  examined  the  same  metallic 
and  acidulous  radicals  were  found  in  each.  This  result  was  con- 
firmed by  repeating  the  experiment  on  two  other  portions  of  the  drugs. 
The  metallic  radicals  present  were  iron,  aluminium,  calcium,  sodium 
and  potassium,  whilst  the  acidulous  ones  were  phosphates,  sulphates 
and  silicates.    The  root  of  chondodendron,  exhausted  by  petroleum 
1Read  before  the  School  of  Pharmacy  Students  Assoc.;  reprinted  from 
Phar.  Jour,  and  Trans.,  Feb.  27,  p.  703. 
