Am^^-19p0^arm-}    Recent  Literature  Relating  to  Pharmacy.  225 
fenchone  and  anethol,  the  different  oils  of  fennel  contain  variable 
quantities  of  pinene,  phellandrene,  dipentene  and  limonene.  All  of 
these  constituents,  however,  vary  with  the  source  or  origin  of  the 
seed. 
In  conclusion,  and  as  an  additional  argument  in  favor  of  the  adop- 
tion of  the  active  constituents  of  essential  oils  as  representing  the 
most  desirable  portion  from  a  medical  point  of  view,  we  may  call 
attention  to  the  fact  that  the  last  edition  of  the  Swedish  Pharmaco- 
poeia has  gone  farther  even  than  the  German,  which  preceded  it  by 
about  two  years,  and  has  adopted  anethol,  carvone,  eucalyptol, 
eugenol  and  cinnamic  aldehyde  as  representing  the  active  constitu- 
ents and  the  medicinally  active  portions  of  the  respective  oils  from 
which  they  are  derived. 
RECENT  LITERATURE  RELATING  TO  PHARMACY. 
RADIOACTIVE  MATTER. 
Radioactive  matter  constitutes  one  of  the  most  interesting  prob- 
lems in  physics  or  chemistry  at  the  present  time. 
The  rapid  accumulation  of  literature  on  the  subject,  the  variety 
and  interesting  nature  of  the  experiments  that  have  been  recorded, 
and  the  numerous,  and  at  times  diverging  opinions  held  by  individ- 
ual experimenters  make  this  a  subject  that  the  ordinary  individual 
can  hardly  expect  to  keep  fully  in  touch  with. 
A  review  of  the  present  status  of  the  problem  by  one  that  has 
been  himself  engaged  in  original  investigations  in  this  line  is  there- 
fore of  more  than  passing  interest. 
W.  Marckwald,  of  the  Chemical  Institute  of  the  University  of 
Berlin,  has  just  published  quite  an  exhaustive  review  of  this  subject 
in  the  Berichte  der  Deutschen  Pharmac cutis c hen  Gesellschaft  (Berlin, 
1903,  page  11).  From  this  paper  much  of  the  following  data  has 
been  taken;  a  few  additional  quotations  have  been  added,  when 
thought  of  sufficient  interest. 
In  1896  Henri  Becquerel  discovered  that  salts  of  uranium  had  the 
peculiar  property  of  emitting  a  form  of  energy  that  readily  penetrated 
opaque  substances,  such  as  paper  or  aluminium  foil,  and  produced 
effects  on  photographic  plates  similar  to  those  produced  by  the  X- 
rays.  In  addition  to  the  property  of  affecting  a  photographic  plate 
through  opaque  substances,  these  rays  of  energy  resemble  X-rays  in 
