532 
ON  HONEY,  ITS  FORMATION  AND  CHANGES. 
liquid  was  then  heated  with  lime  and  carbonic  acid,  filtered,  and 
evaporated  in  vacuo  over  sulphuric  acid,  on  a  glass  slip. 
Some  of  these  results  I  have  on  the  table  before  you.  The 
crystals  are  from  Cheiranthus  Cheiri,  Lonicera  Periclymemim., 
Trifolium  pratense,  and  Rosa  canina.  They  are  very  difficult  to 
separate,  owing  to  the  very  rapid  change  into  glucose  by  the 
chemical  addition  of  a  molecule  of  water.  The  angles  are  very 
decided,  and  measure  90°  and  134*25°.  They  are  very  beautiful 
objects  for  the  polarizing  microscrope,  and  are  most  decidedly 
pure  sucrose. 
The  bee,  then,  led  by  instinct  to  the  favorite  plants,  inserts 
its  ligula  into  the  corolla,  and  laps  up  the  sacchiferous  liquid, 
and  passes  it  into  the  honey  sac.  The  ligula  is  not,  as  was  once 
supposed,  a  hollow  tube,  through  which  a  liquid  may  be  sucked, 
but  is  a  solid,  flexile  organ,  covered  with  circlets  of  hairs.  Like 
the  palate  of  a  mollusk,  it  is  simply  retracted  into  the  mouth, 
and  wiped,  as  it  were,  by  the  fauces. 
While  retained  in  the  honey-bag,  it  receives  the  addition  of  an 
acid  which  possesses  all  the  reactions  of  formic  acid.  It  is  pro- 
bably this  that  causes  the  peculiar  tingling  sensation  in  the  throat 
that  is  frequently  experienced  when  much  honey  is  eaten.  The 
formic  acid  may  perhaps  be  the  result  of  the  decomposition  of  the 
sugar,  thus — 
C12H22On-f  14  0  =  10(HCHO2) ,+  2  C02  +  H20. 
Caue  sugar.  Formic  acid. 
On  arriving  at  the  hive,  the  bee  deposits  the  contents  of  the 
honey-bag  into  the  comb,  where  it  remains  till  the  stock  is  taken. 
At  this  stage,  honey  is  a  clear,  thick,  yellowish  liquid,  having 
a  sp.  g.  1*423,  and  does  not  give  a  blue  with  tincture  of  iodine. 
After  collection,  this  honey  gradually  thickens,  and  deposits 
crystals,  becoming  rather  opaque.  A  bit,  placed  under  the  mi- 
croscope, will  be  seen  to  consist  of  a  mass  of  regularly-formed 
crystals,  floating  in  a  clear  liquid,  and  interspersed  with  pollen- 
granules.  These  crystals  are  those  of  dextro-glucose  ;  they  are 
very  thin  and  transparent,  and  the  measurement  of  their  angles 
is  120°.  They  are  evidently  derived  from  the  gradual  decompo- 
sition of  the  sucrose. 
This  transformation  proceeds  from  day  to  day  till  the  honey 
