52 
ON  SUPPOSITORIES  AND  MEDICATED  PESSARIES, 
to  mitigate  the  distressing  drought,  and  to  annihilate,  perhaps, 
even  that  occasionally  excessive  dry  heat  evolved  by  the  sun's 
rays  from  the  naked  ground  throughout  extensive  regions  of  the 
interior,  and  wafted  with  the  current  of  air  to  the  east  and  south, 
miseries  from  which  the  prevalence  of  sea-breezes  renders  the 
more  littoral  tracts  of  West  and  North  Australia,  almost  free, 
But  in  the  economy  of  nature  the  trees,  beyond  affording  shade 
and  shelter,  and  retaining  humidity  to  the  soil,  serve  other  great 
purposes.    Trees,  ever  active  in  sending  their  roots  to  the  depth, 
draw  unceasingly  from  below  the  surface-strata,  those  mineral 
elements  of  vegetable  nutrition  on  which  the  life  of  plants  abso- 
lutely depends,  and  which,  with  every  dropping  leaf,  is  left  as  a 
storage  of  aliment  for  the  subsequent  vegetation.    How  much 
lasting  good  could  not  be  effected,  then,  by  mere  scattering  of 
seeds  of  our  drought-resisting  acacias  and  eucalypts  and  casua- 
rinas,  at  the  termination  of  the  hot  season,  along  any  water- 
course, or  even  along  the  crevices  of  rocks,  or  over  bare  sands  or 
hard  clays,  after  refreshing  showers  ?    Even  the  rugged  escarp- 
ments of  the  desolate  ranges  of  Tunis,  Algiers,  and  Morocco, 
might  become  wooded :  even  the  Sahara  itself,  if  it  could  not  be 
conquered  and  rendered  habitable,  might  have  the  extent  of  its 
oases  vastly  augmented ;  fertility  might  be  secured  again  to  the 
Holy  Land,  and  rain  to  the  Asiatic  plateau,  or  the  desert  of 
Atacama,  or  timber  and  fuel  be  furnished  to  Natal  and  La  Plata. 
An  experiment,  instituted  on  a  bare  ridge  near  our  metropolis, 
demonstrates  what  may  be  done." 
A  systematic  catalogue  of  the  known  trees  of  Australia,  with 
indications  of  their  territorial  distribution,  occupies  18  pages  of 
this  essay  ;  from  which  it  appears,  that  in  Australia,  no  less  than 
950  woody  plants  attain  a  height  of  at  least  30  feet,  or  there- 
abouts,   a.  G. — Sillimans  Journal,  November,  1867. 
ON  SUPPOSITOKIES  AND  MEDICATED  PESSAKIES. 
By  Barnard  S.  Proctor. 
Now  that  the  dispensing  of  suppositories  is  becoming  a  matter 
of  frequent  occurrence,  it  is  highly  desirable  to  give  publicity  to 
anything  which  will  facilitate  the  operation,  and  diminish  the 
