366 
Otto  of  Rose. 
(  Am.  Jour.  Pharin 
\      July,  1881. 
life^  whose  moral  tone  was  higher  or  better^  in  my  estimation,  than 
that  of  Dr.  Pile. 
From  1814^  when  we  became  intimate,  until  his  death,  1881,  more 
than' sixty-six  years,  we  have  been  friends  when  together,  and  corres- 
pondents while  my  official  duty  separated  us,  often  for  several  years  at 
a  time." 
Those  who  have  been  associated  with  Dr.  Pile  in  business,  or  as  a 
member  of  this  College,  can  fully  endorse  what  has  been  said  by  Dr. 
Ruschenberger,  and  add  thereunto  their  testimony  to  his  character  as 
a  man  deeply  impressed  with  the  duties  and  responsibilities  of  a  Chris- 
tian life,  endeavoring  to  live  void  of  offence  to  his  fellow-men,  and 
steadfast  in  his  faith  as  a  Christian. 
ROSE  OIL,  OR  OTTO  OF  ROSES. 
By  Chalrles  G.  Waknford  Lock. 
This  celebrated  perfume  is  the  volatile  essential  oil  distilled  from  the 
tlowers  of  some  varieties  of  rose.  The  botany  of  roses  appears  to  be  in  a 
transition  and  somewhat  unsatisfactory  state.  Thus  the  otto-yielding  rose 
iH  variously  styled  Rosa  damaseena^  H.  sempervirens^  R.  mosehata^  R.  gal- 
lica^  jR.  cenfifolia,  E.  j^rovincialis.  It  is  pretty  generally  agreed  that  the 
kind  grown  for  its  otto  in  Bulgaria  is  the  damask  rose  [R.  damascena) ^  a 
variety  induced  by  long  cultivation,  as  it  is  not  to  be  found  wild.  It  forms 
a  bush,  usually  3  to  4  feet,  but  sometimes  6  feet  high;  its  flowers  are  of 
moderate  size,  semi-double,  and  arranged  several  on  a  1)ranch,  though  not 
in  clusters  or  bunches.  In  color  thej^  are  mostly  light  red ;  some  few  are 
white,  and  said  to  be  less  productive  of  otto. 
The  utilization  of  the  delicious  perfume  of  the  rose  was  attempted,  with 
more  or  less  success,  long  j^rior  to  the  comparatively  modern  process  of  dis- 
tilling its  essential  oil.  The  early  methods  chiefly  in  vogue  were  the  dis- 
tillation of  rose  water,  and  the  infusion  of  roses  in  olive  oil,  the  latter  flour- 
ishing in  Europe  generally  down  to  the  last  century,  and  surviving  at  the 
l^resent  day  in  the  south  of  France.  The  butyraceous  oil  produced  by  the 
distillation  of  roses  for  making  rose  water  in  this  country  is  valueless  as  a 
perfume,  and  the  real  otto  was  scarcely  known  in  British  commerce  before 
the  present  century. 
The  profltable  cultivation  of  roses  for  the  i:>reparation  of  otto  is  limited 
chiefly  by  climatic  conditions.  The  odoriferous  constituent  of  the  otto  is  a 
liquid  containing  oxj^gen,  the  solid  hydrocarbon  or  stearopten,  with  which 
it  is  combined,  being  absolutely  devoid  of  perfume.  The  proportion  which 
this  inodorous  solid  constituent  bears  to  the  liquid  j^erfume  increases  with 
the  unsuitability  of  the  climate,  varying  from  about  18  per  cent,  in  Bul- 
garian oil  to  35  and  even  68  i^er  cent,  in  rose  oils  distilled  in  France  and 
England.    This  increase  in  the  i^roportion  of  stearopten  is  also  shown  by 
