220 
ON  PYROXYLIN. 
alcohol,  was  treated  with  water ;  the  infusion  was  evaporated 
carefully,  and  the  resulting  extract  was  subjected  to  experiment. 
Thirty  grains  were  taken  by  myself  at  10  o'clock,  A.  M.  At 
12  o'clock,  m.,  no  action  having  been  produced,  the  dose  of 
thirty  grains  was  repeated.  At  1  o'clock  the  dose  of  thirty 
grains  was  again  taken.  This  dose  was  repeated  every  hour 
until  eight  doses  were  taken ;  it  was  then  discontinued,  no  ap- 
parent effect  having  been  produced,  and  the  conclusion  having 
been  arrived  at,  that  such  an  extract  possessed  no  remedial 
powers.  It  has  been  stated  that  this  extract  is  diuretic  in  its 
properties,  but  I  have  not  been  able  to  discover  diuretic,  or  in- 
deed any  other  effects  from  this  dose  of  240  grains. 
From  this  experiment  it  would  appear  that  "Extractum  Ja- 
lapas,"  of  the  IT.  S.  Pharmacopoeia,  is  an  unscientific  prepara- 
tion, being  only  about  one-fourth  as  strong  as  "  Resina  Jalapae  ;" 
the  comparative  yield  of  aqueous  extract  and  alcoholic  extract 
being  about  three  of  the  former  to  one  of  the  latter. — Proc.  of 
the  Amer.  Pharm.  Asso,  1864. 
Philadelphia,  September,  1864. 
ON  PYROXYLIN. 
By  MM.  Pelouze  and  Maurey. 
(Continued  from  page  40,  January  number  ) 
Composition  of  Pyroxylin. — In  1847  we  determined  the  com- 
position of  pyroxylin,  and  represented  it  by  the  following  for- 
mula— C24H17017. 5N05. 
We  must  first  find  out  whether  we  operated  on  a  product  dif- 
ferent to  Lenk's  pyroxylin,  and  if  the  two  are  chemically  iden- 
tical, whether  this  formula  is  correct. 
We  have  conducted  these  researches  with  the  greatest  possi- 
ble care,  and  believe  we  have  surmounted  the  difficulties  of  the 
combustion  of  pyroxylin.  We  found  the  pyroxylin  of  Hirten- 
berg  and  Bouchet  chemically  identical,  and  found  for  them  a 
formula  differing  from  the  previous  one  by  only  one  equivalent 
of  water. 
This  formula  is  C2iH18018.5N05. 
It  is  so  like  the  previous  formula — C24H17017.5NQ5 — that 
analysis  alone  would  not  be  sufficient  to  justify  the  alteration 
