A  october.^Soa"1'}     Recent  Literature  Relating  to  Pharmacy.  495 
coloration  is  hardly  discernible,' but  the  spectrum  shows  the  char- 
acteristic band. 
In  conclusion,  the  writer  suggests  the  method  as  a  colorimetric 
assay,  based  on  brown  color,  formed  in  cold  mixture  of  iodoform 
and  dimethylianilin.  H.  V.  A. 
ANALYSIS  OF  VOLATILE  OILS. 
A  fact  noted  by  M.  Duyk  (Mem.  Acad.  Med.  Brux.,  through  Bull, 
Soc.  Pharm.  Brux.,  1899,  350)  is  likely  to  prove  of  value  in  analysis 
of  volatile  oils.  He  notes  that  when  volatile  oils  are  shaken  with  a 
fairly  concentrated  solution  of  sodium  salicylate,  the  oxygenated 
products,  such  as  eucalyptol,  geraniol,  carvone  and  citral,  are  dis- 
solved, while  the  hydrocarbons  separate,  thus  affording  a  simple 
method  of  separating  these  two  classes  of  volatile  oil  constituents. 
It  moreover  affords  means  of  detection  of  terpenes  in  such  commer- 
cial products  as  carvone  and  eucalyptol.  H.  V.  A. 
THE  CHEMISTRY  OF  THE  RESINS. 
Professor  Tschirch  gave  an  interesting  address  on  resins  at  the  last 
"  Naturforscher  "  convention  {Schweiz.  Wochenschr.  fur  Pharm.  und 
Chem.}  1 899, 470).  From  coniferous  resins  he  separates  the  character- 
istic acids  by  fractional  extraction  of  ethereal  solution  with  dilute  am. 
monium  carbonate  solution  and  O-i  per  cent,  soda  solution  and  subse- 
quent precipitation  of  the  acids  by  hydrochloric  acid.  All  the  resins 
yield  several  acids,  mostly  crystalline,  and  different,  not  only  when 
from  different  plants,  but  also  according  to  varying  manipulation  in 
manufacture.  Thus,  the  naturally  exuding  resins,  the  resins  exud- 
ing through  artificial  wounds,  and  resins  prepared  by  cooking  (like 
colophony)  yield  a  different  variety  of  acid. 
Similar  to  the  coniferous  resin  acids  are  those  yielded  by  the  resins 
of  the  natural  order  Leguminosae.  Of  these,  the  acids  from  Zanzi- 
bar copal  and  of  copaiba  have  been  investigated  by  the  author. 
Those  from  the  last-named  drug  were  its  ethereal  solution,  with  5 
per  cent,  soda  solution  precipitated  by  hydrochloric  acid,  redis- 
solved  in  ether  and  fractionated  by  successive  agitation  with  dilute 
ammonium  carbonate  solution  and  5  per  cent,  soda  solution.  In 
this  way,  five  acids  were  obtained  and  their  chemistry  is  still  being 
studied  by  the  author.  H.  V.  A. 
