274        NEW  PROCESS  FOR  PURE  RESIN  OF  SCAMMONY. 
preserved,  if  instead  of  leaving  such  matter  in  common  air,  they 
were  placed  in  vases  filled  with  air  that  had  been  filtered  through 
cotton.  Flesh,  soup,  and  all  kinds  of  alimentary  substances  can 
thus  be  preserved,  if  the  precaution  has  been  taken  previously 
to  boil  them  in  water. 
Mr.  Schroeder  shows  that  what  he  has  established  concerning 
fermentation  and  putrefaction,  is  aho  true  of  crystallization.  It 
is  well  known  that  a  saturated  solution  of  sulphate  of  soda  re- 
mains liquid  as  long  as  it  is  in  vacuo,  but  solidifies  on  access  of 
air.  Mr.  Schroeder  establishes  the  fact  that  crystallization  does 
not  take  place  if  the  air  is  made  to  pass  through  a  tube  filled 
with  cotton.* 
Mr.  S.  explained  the  results  of  his  experiments  in  1854  by 
supposing  that  the  air  filtered  through  cotton  is  deprived  of  the 
spores  of  cryptogamic  infusoria,  which  are  the  cause  of  putres- 
ence  and  fermentation.  If  the  experiment  on  the  sulphate  of 
soda  tends  to  establish  a  relation  between  fermentation  and 
crystallization,  it  serves  to  prove  also  that  these  phenomena  can 
take  place  without  the  presence  of  these  cryptogamia  or  infusorial 
germs,  suspended  in  unfiltered  air.  This  question  which  appear- 
ed to  us  finished  by  the  earlier  researches  of  Mr.  Schroeder 
comes  up  anew.  These  facts  do  not  interfere  with  the  mechani- 
cal theory  of  Liebig,  nor  that  derived  from  the  recent  researches 
of  Pasteur  on  the  propagation  of  fermentation  The  American 
Journal  of  Science  and  Arts,  January,  1859. 
REPORT  ON  THE  ACTION  OF  WILLIAM  McANDREW  AND 
SON'S  SCAMMONY. 
BY  A.  B.  GARROD,  M,D.,  F.R.S.,  F.R,C.P., 
ProfeBSior  of  Materia  Medica,  Therapeutics  and  Clinical  Medicine  at  University  College,  Physician 
tu  University  College  Hospital. 
Every  physician  in  the  habit  of  prescribing  scammony,  either 
singly,  or  in  combination  with  other  purgatives,  must  have  been 
struck  with  the  uncertainty  of  its  action,  and  of  its  liability  at 
*  Journal  de  Pharmacie  and  de  Chemie,  1854,  T.  xxv.,  p.  314. 
