336 
PRESERVATION  OF  SENNA  BY  FILTERED  AIR. 
PRESERVATION  OF  COLD  INFUSION  OF  SENNA  BY  FILTERED 
AIR. 
According  to  the  observations  of  Dusch  and  Schroder,  moist 
organic  matter  may  be  not  only  kept  for  months  but  for  years, 
under  cold  water,  if  you  put  them  in  a  matrass  and  expose  them 
to  the  heat  of  a  water  bath,  and  close  them  afterwards  with  a 
stopper  of  cotton.  The  authors  try  to  explain  this  wonderful 
fact  by  supposing  that  the  cause  of  the  decomposition  by  pu- 
trefaction or  fermentation  of  organic  matter  depends  on  the  pres- 
ence in  the  water  of  certain  extraordinarily  minute  germs  float- 
ing in  the  air.  The  heat  destroys  these  germs  as  they  exist  in 
the  air  of  the  matrass,  and  the  stopper  of  cotton  put  on  after- 
wards will  allow  the  air  to  pass  in,  but  keeps  back  the  germs 
which  are  contained  in  it. 
This  discovery,  so  theoretically  and  practically  important,  has 
induced  Folberth,  an  apothecary  of  Mediasch  in  Siebenbtfrgen, 
to  try  it  for  the  preservation  of  medicinal  substances  which  are 
apt  to  spoil  easily.  He  first  tried  compound  infusion  of  senna, 
by  heating  a  freshly  prepared  infusion  to  the  boiling  point,  then 
closed  the  matrass  with  a  cotton  stopper,  and  kept  it  in  a  room 
where  the  temperature  was  usually  72°.  After  the  lapse  of  a 
month  he  opened  the  matrass ;  the  infusion  was  clear,  and  not  to 
be  distinguished  by  color,  smell  or  taste  from  one  freshly  pre- 
pared. The  small  sediment  at  the  bottom  of  the  vessel  was  the 
result  of  the  clarification  of  the  fluid  by  deposition.  The  cotton 
stopper  being  replaced  by  a  cork,  mouldiness  began  to  show 
itself  the  second  day. 
An  infusion  prepared  at  the  same  time  and  kept  along  side 
of  the  other,  but  closed  with  a  cork,  exhaled  a  spoiled  smell  on 
the  third  day,  and  mouldiness  on  the  fourth  appeared. 
To  avoid  the  necessity  of  boiling  and  restopping  with  cotton, 
after  each  use  of  the  infusion,  the  author  recommends  the 
use  of  a  syphon  arranged  at  the  beginning  by  passing  it  through 
a  cork,  loosely  closing  the  entrance  and  passing  through  the 
cotton  stopper,  the  long  end  of  the  syphon  being  furnished  with 
a  gum-elastic  tube  and  pressing  spiggot,  or  cut-off,  of  wire.  The 
tube  is  to  be  filled  at  first.  As  the  infusion  is  drawn  off,  the  air 
enters  through  the  cotton,  and  is  deprived  of  its  power  of  inju- 
ring the  liquid. —  Wittsteins  Vierteljahrsschrift,  1862. — F.  L.  J. 
