ANCIENT  USB  OF  ODORIFEROUS  PLANTS. 
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ditions,  and  oxy-chloride  of  aluminium  is  formed,  and  by  push- 
ing the  [process,  alumina  is  obtained  as  the  ultimate  fixed  pro- 
duct.—ilfed  G-az.,  New  York,  Sept  24,  1870, /row  Lancet, 
ANCIENT  USE  OF  ODORIFEROUS  PLANTS. 
In  his  introductory  address  to  the  Medical  Section  of  the 
British  Medical  Association  at  their  late  meeting  at  Newcastle- 
upon-Tyne,  Dr.  Rumsey,  referring  to  a  remarkable  series  of 
observations  which  Professor  Mantegazza  has  reported  to  the 
Institute  of  Lombardy,  made  the  following  remarks  : 
"  The  experiments  were  not  made  under  the  dull  sky  of 
Britain,  but  in  sunny  Italy.    We  have  all  heard  how  Acron  of 
Agrigentum,  and  other  followers  of  Empedocles  the  physicist, 
employed  aromatic  and  balsamic  herbs  as  preventives  of  pesti- 
lence, often  burning  them,  sometimes  planting  them  round  their 
cities.    So  also  Herodian  records  {Langius  Jo,,  Florilegium^ 
Morbus,  p.  1854 ;  Lugduni,  1648)  that,  in  a  plague  which  de- 
vastated Italy  in  the  second  century — the  counsel  of  the  doctors 
having  been  taken — strangers  crowding  into  Rome  were  directed 
to  retreat  to  Laurentum,  now  San  Lorenzo,  that  by  a  cooler  at- 
mosphere, and  hy  the  odor  of  laurel,  they  might  escape  the  danger 
of  infection.    Some  of  us  may  have  smiled  at  the  latter  part  of 
the  advice.    Could  the  scent  of  herbs  and  flowers  do  more  than 
conceal  the  presence  of  infectious  matter  in  the  air  ?  Mante- 
gazza now  replies  in  the  affirmative.    He  says  that  in  the  oxi- 
dation of  the  essences  of  odoriferous  plants  a  large  quantity  of 
ozone  is  evolved,  at  least  as  much  as  is  produced  b^  phosphorus 
or  electricity ;  also  that,  in  the  greater  number  of  these  cases, 
ozone  is  developed  only  by  the  direct  rays  of  the  sun,  although 
in  others  the  action,  commencing  in  solar  light,  is  found  to  con- 
tinue in  darkness.    Some  details  of  these  interesting  experi- 
ments have  appeared  in  the  scientific  periodicals,  so  I  need  only 
mention  that  among  the  plants  which  largely  develope  ozone  on 
exposure  to  the  rays  of  the  sun,  are  cherry-laurel,  clove  and 
lavender ;  among  flowers,  the  narcissus,  hyacinth  and  migno- 
nette ;  and  among  perfumes,  similarly  exposed,  eau  de  Cologne, 
oil  of  bergamot  and  some  aromatic  tinctures.    Flowers  destitute 
