AmXp0r?^•l:l96arm•}        Botany  and  Materia  Medica.  219 
first  observations  were  made  on  plants  in  the  open  air  in  the  locali- 
ties in  which  they  grew.  The  subsequent  experiments  were  made 
with  plants  cultivated  in  a  greenhouse  in  which  were  no  known 
poisonous  plants.  Careful  tests  were  made  with  C.  spectabile  on 
nine  persons,  six  of  whom  were  poisoned  in  a  degree  corresponding 
to  the  manner  of  application  of  the  plants  to  the  skin.  C.  pubescens 
gave  about  the  same  results,  and  C.  parviflorum  also  exhibited 
dermatic  action. 
Specimens  of  the  pointed  and  glandular  hairs  found  in  abundance 
over  the  entire  plant  were  removed  and  touched  separately  to  the 
skin.  It  was  shown  that  the  irritant  action  was  due  to  the  secretion 
of  the  glandular  hairs  only.  If  the  development  of  the  glandular 
hairs  is  followed,  it  will  be  found  that  the  secretion  begins  to  accu- 
mulate in  the  distal  end  of  the  cell  shortly  before  it  reaches 
maturity  and  filters  through  the  wall,  forming  a  reservoir  between 
the  wall  and  the  outer  cuticle  layer.  On  account  of  the  extreme 
small  quantity  of  the  secretion,  its  exact  chemical  nature  could  not 
be  ascertained.  It  was  found  to  be  soluble  in  alcohol,  and  gave  the 
reactions  of  an  oily  substance. 
It  was  found,  further,  that  the  irritant  action  of  the  plants  on  the 
skin  increased  with  the  development  of  the  plant,  and  reached  a 
maximum  effect  during  the  formation  of  the  seed  capsules.  This 
corresponds  with  the  activity  of  the  glandular  cells  and  the  amount 
of  secretion  present. 
Phosphate  Production. — For  the  past  year  or  two  a  good  deal  of  apprehension 
has  been  felt  by  phosphate  producers  in  this  country  and  elsewhere,  as  to  the 
competition  of  the  African  deposits.  The  extent  of  those  deposits  was  out- 
lined in  The  Mineral  Industry,  Vol.  Ill,  but  their  present  importance  has  been 
very  much  exaggerated  by  general  report.  The  Tunisian  mines  are  not  yet 
worked  to  any  considerable  extent,  and,  according  to  PEngrais,  the  total  pro- 
duction of  Algeria  in  1895  was  121,475  metric  tons,  which  is  only  a  very  small 
amount  compared  with  the  total  consumption  of  Europe  alone.  At  present, 
very  little  work  is  in  progress,  owing  to  the  difficulties  over  the  concessions  at 
Tebessa  and  elsewhere.  Our  Florida  producers  have,  apparently,  no  occasion 
to  be  alarmed  at  African  competition  for  some  years  to  come.  A  more  formid- 
able interference  with  their  business  is  found  in  the  rapidly  increasing  use  of 
Thomas  slag  as  a  source  of  supply  of  phosphoric  acid.  The  quantity  of  this 
slag  produced  in  Germany  and  Belgium  is  growing,  and  its  application  in  the 
manufacture  of  fertilizers  has  been  promoted  by  its  abundance  and  cheapness, 
so  that  it  has  become  a  considerable  article  of  commerce. — The  Engineering 
and  Mining  Journal,  February  1,  1896. 
