c 
492  URTICA  DIOICA,  (STINGING  NETTLE.) 
adapted  for  liniments,  into  many  of  which  it  enters ;  it  is  also 
used  as  a  carminative. 
In  conclusion  it  may  be  remarked  that  sassafras  is  employed 
much  more  in  domestic  practice  than  by  physicians.  Its  bark 
is  used  officinally  in  the  compound  decoction  of  sarsaparilla,  its 
pith  in  mucilage  sassafras,  and  its  oil  in  troches  of  cubeb ;  but 
in  many  cases  where  the  bark  might  be  employed  it  is  passed 
by.  When  finely  powdered,  the  bark  of  sassafras  is  better  than 
Peruvian  bark  for  dentifrices,  having  its  astringency  and  anti- 
septic power  with  the  grateful  aroma  of  the  sassafras ;  besides 
its  powder  is  very  like  cinchona  in  color.  The  alcoholic  extract 
of  the  fresh  bark  is  a  deep  red  astringent  substance,  strongly 
aromatic  and  pungent.  It  is  not  improbable  that  other  barks, 
as  cinchona,  may  resemble  sassafras  in  being  nearly  colorless 
when  in  a  growing  state  and  altering  by  the  drying  process. 
The  writer  believes  he  has  somewhere  seen  this  remarked  of 
recent  cinchona  bark.  It  is  probable  that  this  change  occcurs  in 
cinnamon  bark  during  the  process  of  drying,  and  possibly  also  in 
Krameria  root.  The  actual  changes  that  occur  in  this  trans- 
formation of  tannin  is  worthy  of  a  closer  study  by  organic 
chemists  than  they  have  yet  given  it. 
ON  URTICA  DIOICA  (STINGING  NETTLE). 
By  Benjamin  Shoemaker,  Jr. 
(Extract  from  an  Inaugural  Essay.) 
The  object  of  the  author  in  writing  on  this  plant  was  to  dis- 
cover, if  possible,  upon  what  constituent  the  diuretic  properties 
of  the  root  depended.  The  plant  is  covered  with  minute  tubular 
hairs,  which  transmit  a  poisonous  fluid  on  being  pressed.  This 
fluid  is  said  to  be  formic  acid.  The  root  is  known  to  possess 
diuretic  properties.  An  infusion  of  the  root  has  been  used  by 
some  physicians  of  this  city  with  great  success  in  cases  of  dropsy, 
and  other  diseases  where  a  diuretic  medicine  was  indicated.  The 
author  inferred  that  the  diuretic  power  depended  on  a  volatile 
principle. 
One  pound  of  the  ground  root  was  exhausted  with  water,  and 
the  infusion  evaporated  to  a  pint,  during  which  a  disagreeable 
