560 
IRON  AND  HYDROGEN. 
articles  of  diet  as  with  cassava  or  chocolate,  or  in  the  form  of 
drink,  prepared  by  scraping  it,  and  suspending  the  powder  in 
sweetened  water.  It  is  considered  by  them  useful  in  the  preven- 
tion and  cure  of  bowel  complaints.  Dr.  Gravrelle,  who  was  for- 
merly physician  to  Dom  Pedro,  in  Brazil,  called  the  attention 
of  the  profession  to  it  some  years  since  in  France.  He  had 
found  it  advantageous  in  the  diarrhoea  of  phthisis,  sick  head- 
ache, paralysis,  tedious  convalescence,  and  generally  as  a  tonic. 
By  Dr.  Ritchie,  surgeon  in  the  British  Navy,  it  is  highly  re- 
commended in  irritation  of  the  urinary  passages.*  Dr.  Herve 
has  been  in  the  habit  of  using  it  daily  for  five  or  six  years,  and 
has  never  failed  to  derive  advantage  from  it  in  idiopathic  diar- 
rhoea, even  in  the  most  obstinate  cases. f 
It  may  be  given  in  substance,  in  the  quantity  of  one  or  two 
drachms,  scraped  into  powder,  and  mixed  with  sweetened  water, 
but  the  most  convenient  form  of  administration  is  that  of  spir- 
ituous extract.  According  to  M.  Dechastelus,  alcohol  is  the 
only  agent  which  completely  extracts  its  virtues,  ether  and  wa- 
ter effecting  this  object  but  partially.  Of  the  extract  eight  or 
ten  grains  may  be  given  during  the  day,  in  the  form  of  pill.  It 
may  also  be  taken  along  with  chocolate  as  a  drink.  J 
Another  species  of  Paullinia  (P.  cupana)  growing  on  the 
banks  of  the  Orinoco  river,  is  also  said  to  yield  a  similar  sub- 
stance. Guarana,  or  Paullinia,  as  it  is  sometimes  called,  has 
never  obtained  general  favor  in  this  country. — Pharm.  Journ.^ 
London,  Sept.  17,  1870. 
IRON  AND  HYDROGEN. 
By  Dr.  Klein. 
The  author,  a  pupil  and  collaborator  of  Professor  Jacobi,  of 
St.  Petersburg,  states,  that  the  iron  obtained  by  electrolysis  is 
not,  as  has  been  often  thought,  the  pure  metal,  but,  on  the  con- 
trary, a  compound  or  mixture  of  iron  and  hydrogen,  which,  when 
heated  to  redness,  gives  off  an  enormous  amount  of  that  gas,  and 
becomes,  while  greatly  increasing  in  bulk,  a  silver-white,  very 
*^-D.  Month.  Journ.  Med.  Sc.  N.S.  v.  p.  467. 
^Brit.  and  For.  Med.  Chir.  Rev.^  Jan.  1858,  p.  192. 
t  United  States  Dispensatory,  12th  ed.  p.  1578. 
