222  Some  Notes  on  Essential  Oils.       { Am  M°ay?iloh3arm' 
claim  to  have  perfected  their  artificial  oil  to  such  an  extent  that  the 
natural  oil  can  be  completely  dispensed  with.  The  product  is  said 
to  replace,  not  alone  the  oil,  but  also  the  perfume  of  orange  flowers 
made  by  maceration  or  extraction. 
In  addition  to  artificial  oil  of  neroli,  a  substance  that  has  been 
given  the  name  nerolin  is  used  extensively  as  a  substitute  for  the 
natural  oil.  Nerolin  is  met  with  in  commerce  as  a  white  crystalline 
powder.  It  is  particularly  applicable  to  the  perfuming  of  soap,  not 
being  attacked  by  hot  lye.  On  account  of  its  comparatively  low 
price  it  is  used  extensively  in  the  manufacture  of  cheaper  grades  of 
toilet  soap.  It  is  readily  soluble  in  alcohol  and  essential  oils,  and 
is  said  to  be  a  very  powerful  and  lasting  perfume.  The  effect  that 
these  synthetic  and  artificial  products  have  had  on  the  price  of  the 
natural  oil  has  already  been  mentioned.  In  addition  to  the  marked 
reduction  in  price  the  quality  of  the  natural  oil  is  said  to  have  been 
improved  by  greater  care  in  its  production. 
Oil  of  Orange.- — The  specific  gravity  of  this  oil,  according  to 
Gildemeister  and  Hoffmann,  varies  from  0-848  to  0-852.  The  specific 
gravity  as  given  in  the  different  national  Pharmacopceias  differs 
from  0-830,  the  minimum  in  the  Russian,  to  0-870,  the  maximum 
of  the  Dutch  Pharmacopoeia.  The  optical  rotation  of  this  oil  varies 
from  plus  96  to  plus  98.  Oil  of  orange  peel  is  said  to  vary  much 
less  in  its  physical  constants  than  either  oil  of  bergamot  or  oil  of 
lemon.  The  chief  constituents  of  the  oil  are  limonene  and  citral. 
In  this  connection  it  may  be  interesting  to  note  that  practically  all 
of  the  oils  of  the  citrus  group  are  imported,  little  or  no  oil  of  a  satis- 
factory quality  being  made  in  this  country. 
Oil  of  Anise. — As  is  well  known,  commercial  oil  of  anise  is 
derived  from  two  distinct  and  widely  different  plants.  The  true  oil 
of  anise  seed  is  obtained  from  the  fruit  of  Pimpinella  Anisum,  L.,  an 
annual  umbelliferous  plant,  while  what  is  usually  sold  as  oil  of  anise, 
in  this  country  particularly,  is  obtained  from  the  fruit  of  Illicium 
Verum,  Hook.,  an  evergreen  shrub  belonging  to  the  natui-al  order 
Magnoliacese,  and  indigenous  to  China. 
The  physical  properties  of  these  two  oils  are  very  much  the  same, 
though  they  differ  materially  in  their  chemical  composition.  True 
oil  of  anise,  according  to  Schimmel  &  Co.,  consists  of  anethol,  anise 
ketone  and  methyl  chavicol,  while  the  oil  of  star  anise,  in  addition 
to  anethol  and  methyl  chavicol,  also  contains  pinene,  phellandrene, 
