222 
OZONE  PRODUCED  BY  PLANTS. 
chloroformists  found  an  early  and  eminent  representative  in  T. 
E.  Petrequin,  chief-surgeon  of  the  Hotel  de  Lyon.  For  nearly 
twenty  years  he  has  banished  chloroform  and  used  ether  in  that 
hospital,  the  largest  in  France,  where  from  fourteen  to  fifteen 
thousand  patients  are  treated  annually,  and  where  more  opera- 
tions are  performed  than  in  any  other.  From  this  telling  ex- 
perience, Petrequin  Diday,  and  in  fact  l'Ecole  de  Lyon,  asserts 
that  pure  ether  has  accomplished  in  their  hands,  without  acci- 
dent, those  services  which  chloroform  has  rendered  elsewhere  at 
a  cost  of  several  hundred  lives.  Is  not  this  question  worthy  of 
further  study  ?  Yours,  etc., 
E.  Seguin,  M.  D. 
— The  Medical  Record. 
OZONE  PRODUCED  BY  PLANTS. 
Professor  Daubeny  of  Oxford  has  contributed  to  the  Journal 
of  the  Chemical  Society,  for  January  last,  an  interesting  article, 
giving  the  details  of  a  series  of  careful  experiments,  which  go 
to  prove  that  green  foliage,  in  assimilating  carbonic  acid,  water, 
&c,  liberates  a  part  of  the  oxygen  in  the  form  of  ozone.  After 
his  experiments  were  made,  Dr.  Daubeny  found  that  Kosmann 
of  Strasburg  had  reached  the  same  conclusion,  but  through  less 
refined  experiments.  Referring  to  the  first  "paper  he  ever  com- 
municated to  a  scientific  society,  that  published  in  the  Philosoph- 
ical Transactions  for  1834,  on  the  evolution  of  oxygen  gas  by 
plants  in  the  day-time,  Dr.  Daubeny  concludes  :  "  Should  I  now 
have  established  to  the  satisfaction  of  the  scientific  world,  that 
these  same  green  parts  of  plants,  at  the  very  time  they  are  emit- 
ting oxygen,  convert  a  portion  of  it  into  ozone,  I  might  hope 
that  these  researches  of  my  later  years  will  serve  appropriately 
to  wind  up  those  undertaken  in  my  younger  ones,  by  showing 
that  vegetable  life  acts  as  the  appointed  instrument  for  counter- 
acting the  injurious  effects  of  the  animal  creation  upon  the  air 
we  breathe,  not  merely  by  restoring  to  it  the  oxygen  which  the 
latter  had  consumed,  but  also  by  removing,  through  the  agency 
of  the  ozone  it  generates,  those  noxious  effluvia  which  are  en- 
