838 
RESPIRATION  OF  FRUITS, 
glaciers,  so  well  known  to  the  photographers.  Another  Frith 
may  also  show  us  the  wonderful  passages  in  the  interior  of  the 
Pyramids  more  clearly  than  they  have  ever  been  seen  by  the 
traveller  with  the  help  of  the  two  or  three  candles  which  light 
his  way  through  the  dark  labyrinth,  and  enable  us  at  our  own 
firesides  to  gaze  with  awe  on  the  vast  range  of  subterranean 
tombs  at  Serapeum.  All  these  and  many  more  objects  are  now 
open  to  an  enterprising  man,  who  will,  no  doubt,  soon  be  found 
to  avail  himself  of  them.- — Chemical  News,  London*  April  9th, 
1864. 
EESFIRATION  OF  FRUITS. 
M.  Cahours  has  made  an  examination  of  the  respiration  of 
fruits ;  he  considers  that  the  fruit  is  one  of  the  most  important 
organs  of  vegetables,  and  that  the  examination  of  respiration 
should  be  by  no  means  confined  to  the  green  part  of  the  plant. 
He  has  endeavored  to  study  the  proportion  of  gases  contained 
in  the  parenchyma  of  the  pericarp  and  their  composition  ;  the 
action  of  fruit  upon  the  gas  of  respiration,  i.e.,  oxygen,  whether 
alone  or  mixed  with  nitrogen ;  the  action  upon  the  same  gas  of 
each  of  the  envelopes  of  the  fruit  and  of  its  fleshy  part  when 
it  exists.  It  was  found  that  apples,  oranges,  citrons,  in  a  state 
of  maturity,  placed  under  bell  jars  containing  oxygen,  or  mix- 
tures of  oxygen  with  nitrogen,  consumed  a  quantity  of  oxygen, 
and  furnished  an  equal  amount  of  carbonic  acid,  the  proportion 
being  greater  in  diffuse  light  than  in  darkness.  It  is  effected 
gradually  up  to  a  certain  point,  beyond  which  it  augments  con- 
siderably, and  the  internal  face  of  the  skin  presents  some  al- 
teration. The  amount  of  carbonic  acid  produced  increases 
with  the  temperature.  The  fruit  acts  in  the  same  manner 
during  the  time  elapsing  between  its  losing  its  green  color  and 
its  obtaining  its  maturity,  and  that  of  its  obtaining  its  maturity 
and  of  its  commencement  of  decay  ;  but  as  soon  as  this  has 
once  commenced  the  amount  increases  rapidly.  Determinations 
were  made  of  the  proportions  of  gases  contained  in  the  juices. 
To  accomplish  this,  the  fruit  was  squeezed  under  mercury,  and 
the  juice  collected  in  a  flask,  to  which  was  afterwards  adapted 
a  tube  by  a  cork,  but  it  was  found  that  the  same  result  was  ob- 
