Am.  Jour.  Pharm.j 
March,  19 17  J 
Phytochemical  Research. 
107 
land  that  the  use  of  an  extract  of  this  root  in  cases  of  cancer  had 
been  attended  with  beneficial  results,  and  shortly  afterwards  atten- 
tion was  directed  in  Germany  to  the  use  of  choline  in  the  treatment 
of  this  disease.  Some  particular  significance  would  seem  to  be 
imparted  to  these  quite  independent  observations  by  the  fact  that 
taraxacum  root  has  been  found  to  contain  choline,  but  the  value 
of  the  suggested  remedies  has  apparently  not  been  further  confirmed. 
It  occasionally  happens  that  an  investigation  may  gain  in  interest, 
if  not  in  practical  importance,  through  developments  in  a  direction 
that  would  at  first  seem  quite  divergent  from  the  original  subject 
of  inquiry.  Some  recently  published  researches  by  Russian  chemists 
relating  to  the  formation  and  chemical  composition  of  rubber  may 
serve  to  illustrate  such  an  occurrence  as  I  have  indicated,  while  also 
helping  to  elucidate  some  problems  in  plant  metabolism.  In  order, 
however,  that  the  points  of  connection  between  the  results  of  two 
quite  distinct  investigations  may  be  more  clearly  apparent,  the  pur- 
pose and  sequence  of  these  investigations  should  first  be  explained. 
A  good  many  years  ago  a  discussion  arose  respecting  the  solu- 
bility in  alcohol  of  the  oil  of  bay,  as  distilled  from  the  leaves  of 
Myrica  acris  DC,  it  having  been  stated  by  the  Pharmacopoeia  that 
the  oil  was  soluble  in  an  equal  weight  of  alcohol,  whereas  it  was 
contended  by  some  observers  that  it  yielded  a  turbid  solution,  and 
consequently  that  the  official  statement  was  incorrect.  Subsequent 
Observations  had  shown  that  the  freshly  distilled  oil  usually  yields 
a  perfectly  clear  solution  with  90  per  cent,  alcohol,  but  that  when 
the  oil  has  been  kept  for  some  time  its  solubility  becomes  impaired. 
In  order  to  ascertain  the  cause  of  this  change,  the  oil  was  submitted 
to  a  complete  chemical  examination.18  One  of  the  most  important 
results  was  the  isolation  of  a  so-called  olefinic  terpene,  an  open  chain 
hydrocarbon  of  the  composition  C10H16,  whose  constitution  may 
probably  be  expressed  by  one  of  the  following  formulae: 
CHsx  CH3\ 
>C:CH.CH2.CH2.C.CH:CH2  or  xC.CH2.CH2.CH2.C.CH:CH2 
CH/                         II  CH2^  || 
CH2  CH2 
This  compound,  which  possesses  a  density  lower  than  that  of 
the  ordinary  terpenes,  and  contains  three  ethylenic  linkings,  was  the 
first  known  representative  of  its  class,  and  has  been  designated 
myrcene.  On  hydration,  an  alcohol  was  produced  which  possessed 
the  odor  of  linalool,  and  this  on  oxidation  yielded  citral. 
18  Power  and  Kleber,  Pharm.  Rundschau  (New  York),  1895,  13,  p.  60. 
