10  The  Oils  of  Winter  green  and  Birch.  {Am-/a°nufi8p9Sarm- 
ducted  under  bis  direction,  it  would  be  a  matter  of  interest  to  know 
why  he  suggested  such  unreasonable  treatment,  and  why  he  now  boils 
the  mixture  for  only  two  hours.  He  might  also  explain  why  he 
allowed  Mr.  Pettigrew  in  the  same  investigation  to  record  the  specific 
gravity  of  1*0318  for  oil  of  wintergreen  at  22°  C. 
Prof.  Power's  experience  with  oil  of  birch  narrows  down  to  the  in- 
vestigation of  Mr.  Pettigrew,  and  more  recently  his  own  on  what  he 
claims  was  an  adulterated  sample,  which  adulteration,  if  true,  would 
certainly  render  his  results  worse  than  useless.  In  view  of  the  above  it 
is  not  surprising  that  he  failed  to  find  benzoic  acid  in  the  natural  oils, 
and  his  method  of  attempting  to  throw  doubt  on  the  occurrence  of  ethyl 
alcohol  in  the  oils,  by  vague  statements  about  oil  of  turpentine  pro-, 
ducing  the  iodoform  reaction,  is  simply  pitiable.  Right  here,  there- 
fore, we  may  say  with  emphasis  that  such  reasoning  at  the  writing 
table  will  not  take  the  place  of  figures  obtained  in  the  laboratory. 
In  regard  to  the  third  sample  examined  by  Prof.  Power,  which  he 
designates  "  synthetic  oil  of  wintergreen/'  we  suggest  that  it  would 
have  been  more  in  accordance  with  his  results,  had  he  named  it  "  syn- 
thetic oil  of  birch."  It  would  have  been  more  scientific  had  he  pro- 
cured his  sample  in  the  open  market  as  we  did.  In  reply  to  the 
elaborate  reasoning  by  which  he  attempted  to  show  that  our  sample 
could  not  have  contained  benzoate  of  methyl,  we  answer  that  we  pur- 
posely said  nothing  about  benzoate  of  methyl,  but  merely  stated  that 
benzoic  acid  was  present  in  the  sample  of  artificial  oil  examined  by  us. 
It  is  our  opinion  that  it  was  a  mixture  of  methyl  salicylate,  ethyl 
salicylate  and  ethyl  benzoate.  Such  a  product  could  easily  be  made 
to  conform  with  the  specific  gravity  and  boiling  point  given.  As  the 
artificial  oil  was  of  secondary  importance  in  our  work,  we  did  not  at- 
tempt to  investigate  the  alcohol,  and  therefore  merely  stated  that  we 
found  benzoic  acid. 
Finally  in  his  summary  Prof.  Power  flatly  contradicts  himself 
when  he  asserts  that  the  artificial  cannot  be  distinguished  from  the 
natural  oil  by  adding  an  "  excess  of  potassium  hydrate 99  as  stated  by  us. 
He  says  "  on  heating  either  of  these  oils,"  that  is,  the  natural  or  artifi- 
cial product,  "  with  a  caustic  alkali  the  wintergreen  odor  is  naturally 
destroyed  since  the  chemical  compound  to  which  the  odor  is  due  be- 
comes thereby  decomposed."  It  is  true  that  the  methyl  salicylate  is 
decomposed  and  its  odor  disappears,  but  what  becomes  of  the  hydro- 
carbon ?    We  admit  that  the  latter  might  be,  and  probably  is  deconi- 
