I06  Phy  to  chemical  Research.  (Amka?cf  1917™' 
inhaled  it  is  exceedingly  pungent,  affecting  particularly  the  mucous 
membranes  of  the  nose  and  eyes.  A  complete  examination  of  the 
oil  has  shown  it  to  contain  pinene,  eugenol,  eugenol  methyl  ether, 
safrole,  and  a  considerable  proportion  of  cineol,  but  its  chief  con- 
stituent, and  that  to  which  its  peculiar  pungency  is  due,  is  a  ketone 
of  the  composition  C10H14O,  which  has  been  designated  umbellulone. 
As  an  illustration  of  the  chemical  interest  pertaining  to  a  plant 
which  is  quite  cosmopolitan  in  its  distribution,  the  constituents  of  the 
common  Dandelion,  Taraxacum  officinale  Weber,  may  be  briefly 
considered.  The  root  of  this  plant,  as  is  well  known,  is  used  to  a 
considerable  extent  medicinally,  and,  together  with  extracts  pre- 
pared therefrom,  has  long  been  recognized  by  most  of  the  national 
pharmacopoeias.  A  comparatively  recent  examination  of  English 
taraxacum  root17  revealed  the  presence  of  a  somewhat  unexpected 
number  of  interesting  compounds,  some  of  which  had  not  hereto- 
fore been  described.  It  was  found  to  contain,  for  example,  two 
new,  handsomely  crystalline,  monohydric  alcohols,  one  of  which 
possesses  the  formula  C29H47.OH,  and  has  been  termed  taraxasterol, 
while  the  other  has  the  formula  C25H39.OH,  and,  being  a  homologue 
of  the  former  compound,  has  been  designated  homotaraxasterol. 
Both  of  these  compounds  are  members  of  a  series,  which  may  be 
represented  by  the  general  formula  CnH2„_10O.  There  was  also 
isolated  a  small  amount  of  p-hydroxyphenylacetic  acid,  C6H4(OH).~ 
CH2.C02H,  which  had  not  previously  been  observed  to  occur  as 
such  in  the  vegetable  kingdom,  and  3 : 4-dihydroxycinnamic  acid, 
C6H3(OH)2.CH :  CH.C02H,  together  with  a  number  of  the  com- 
monly occurring  fatty  acids,  such  as  oleic,  linolic,  palmitic,  cerotic, 
and  melissic  acids.  Furthermore,  there  was  found  a  phytosterol 
glucoside,  a  small  amount  of  choline,  C5H1502N,  and  a  consider- 
able quantity  of  a  sugar,  which  appeared  to  consist  chiefly  of  laevu- 
lose.  When  an  extract  of  taraxacum  undergoes  the  so-called 
mucous  or  viscous  fermentation,  it  has  been  observed  to  contain 
mannitol,  but  this  does  not  preexist  in  the  root.  Its  formation  would 
appear  to  be  easily  explained  by  the  fact  that  the  root  of  the  plant, 
like  other  Composites,  contains  an  abundance  of  inulin,  which,  on 
hydrolysis,  is  converted  into  lsevulose,  and  the  latter,  by  the  special 
fermentative  process  referred  to,  becomes  reduced  to  mannitol. 
It  would  appear  of  interest  to  note  that  while  the  chemical 
examination  of  taraxacum  was  in  progress  it  was  recorded  in  Eng- 
17  Power  and  Browning,  Jour.  Chem.  Soc,  1912,  101,  pp.  241 1-2429. 
