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ME.  C.  GEEVILLE  WILLIAMS  ON  THE  CONSTITUTION 
great  differences  became  apparent  in  their  beha\iom’.  The  portions  boiling  between 
160°  and  188°  were  scarcely  affected;  they  floated  above  the  solution  of  the  bisulphite, 
and  after  contact  for  weeks,  showed  scarcely  a trace  of  crystalline  compound.  The  fluids 
boihng  at  intermediate  points  yielded  more  crystals  as  their  point  of  ebullition  became 
higher;  and  when  a boiling-point  of  210°  was  reached,  the  oil  (treated  as  before)  became 
semi-solid  in  about  two  hours ; and  from  that  temperature  to  238°,  the  tendency  to  ^deld 
crystals  on  agitation  with  the  bisulphites  increased. 
Bisulphite  of  ammonia  was  found  to  be  a more  convenient  reagent  than  the  corre- 
sponding salt  of  soda,  the  resulting  salt  being  more  ciy^stalline,  and  procurable  with 
greater  ease  in  a state  of  purity.  AVhen  the  fractions  distilling  in  the  twelfth  rectifi- 
cation at  232°  and  upwards  were  treated  with  bisulphite  of  ammonia,  the  whole  solidi- 
fied, in  the  course  of  twelve  hours,  to  a crystalline  mass  of  such  firm  texture,  as  to  be 
with  difficulty  penetrated  by  a glass  rod.  The  very  last  fractions  distilling  at  260°  and 
upwards  yielded  less  crystalline  masses,  retaining  traces  of  an  empyreumatic  oil. 
The  analyses  and  vapour-density  determinations  described  in  this  paper  were  all  made 
upon  fluids  obtained  by  the  following  process.  The  crystalline  substance  from  the 
lower  fractions  was  thrown  upon  a filter,  and  well  washed  with  a saturated  solution  of 
bisulphite  of  ammonia,  which  mechanically  carried  away  much  of  the  oily  impurities. 
The  product  of  this  operation  was  a snow-white  mass  with  a rich  pearly  lustre.  It  was 
carefully  removed  to  a fresh  piece  of  filtering-paper,  and,  a few  folds  inteiwening,  laid 
upon  a porous  tile.  In  the  course  of  a few  hours  the  mass  became  firm  enough  to  be 
removed,  and  being  folded  in  several  fresh  pieces  of  filtering-paper,  wus  again  placed 
between  tiles  and  subjected  to  considerable  pressure.  This  was  repeated  until  the  paper 
ceased  to  receive  any  stain.  The  crystalline  solid  was  then  transferred  to  a stoppered 
vessel,  and  gently  heated  with  a strong  solution  of  potash.  In  a short  time  the  com- 
pound was  decomposed,  the  aldehyde  floating  on  the  surface  in  the  form  of  an  oil. 
The  aldehyde  thus  procured  was  colourless ; it  possessed  a pleasing  fragrance,  totally 
different  from  the  nauseous  odour  of  the  plant  itself.  Its  boiling-point,  as  fii'st  pre- 
pared, fluctuated  considerably,  arising  partly  from  oxidation  and  consequent  formation 
of  other  bodies,  and  partly  from  the  presence  of  a small  portion  of  another  aldehyde. 
The  oxidation  could  only  be  prevented  by  performing  the  operation  in  a current  of 
hydrogen,  an  exceedingly  inconvenient  process  in  fractional  distillations,  the  apparatus 
having  to  be  taken  apart  every  few  minutes.  In  the  course  of  the  experiments  a con- 
siderable number  of  specimens  were  obtained,  but  they  all  had  the  same  composition 
and  vapour-density.  By  carefully  collecting  the  residues  of  the  distillations,  and 
redistilling  in  minute  retorts,  blown  from  glass  tubing,  about  sixty  grains  of  the  second 
aldehyde  were  obtained,  still  however  contaminated  by  some  of  the  fluid  having  the 
lower  formula. 
The  first  aldehyde  yielded  on  analysis  the  following  numbers : — 
I.  T982  gramme  gave  *5643  gramme  carbonic  acid  and  "2329  water. 
II.  ‘2067  gramme  gave  'bSIS  gramme  carbonic  acid  and  ’2475  water. 
