482         CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  L906,   PART    T. 
where  86  per  cent  is  recovered.     The  company  has  six  furnaces  of] 
50  horsepower  each,  with  a  daily  capacity  of   170  pounds  of  phos- 
phorus,   a    total   of    1,020   pounds   a    day.     The    production   varies 
according  to  the  demand. 
The  General  Chemical  Company,  a  small  domestic  manufacturer 
and  the  successor  of  Mr.  Phillips  in  Philadelphia,  recently  acquired 
the  Duncan  patent.  Another  company  was  formerly  established  at 
Long  Island  City.  X.  Y.,  where  it  operated  furnaces  by  electricity 
from  the  city  supply. 
At  the  census  of  1900  three  establishments  were  reported  in  opera- 
tion, hut  at  the  1904-5  census  only  the  Oldbury  Electro-Chemical 
Company,  of  Niagara  Falls,  reported. 
The  American  Phosphorus  Company  buill  its  first  mill  al  Moores 
Mill,  near  Mount  Holly  Springs,  Pa.,  in  L902,  and  the  old  method  of 
heating  by  gas  was  employed.  This  mill  burned  down  and  another 
was  built  and  put  into  operation  by  1905.  Electric  furnaces  were 
installed  in  the  new  plant  and  operated  during  L905,  but  the  pro- 
duction of  electricity  by  steam  was  too  expensive,  and  in  L906  the 
mill  was  moved  t<>  Yorkhaven,  Pa.,  where  electricity  generated  by 
water  power  could  be  had.  The  process  in  use  by  this  company  is 
that  of  (i.  ('.  Landis,  its  chemist,  and  is  kept  a  secret,  as  it  is  claimed 
that  it  is  a  marked  improvement  on  previous  methods.  As  far  as 
could  he  learned  for  publication  without  detriment  to  the  company's 
interest,  the  wavcllite  (aluminum  phosphate)  and  phosphorite  (cal- 
cium phosphate),  which  at  present  is  obtained  from  South  Carolina, 
are  roasted,  mixed  with  silica  and  charcoal,  and  reduced  in  a  pat- 
ented electric  furnace.  The  slag  is  removed  i^\^vy  three  or  four 
hours,  and  the  phosphorus  fumes  are  condensed  under  water  in  the 
crude  yellow  waxy  form  which  requires  refinement.  Eighty-fiv<  to 
'.)()  pei'  cent  of  the  phosphorus  in  the  ore  is  said  to  he  extracted.  The 
average  production  of  this  plant  for  the  last  three  years  is  reported 
to  he  oOO  pounds  a  day. 
In  addition  to  the  domestic  production,  the  United  States  imports 
annually  30,000  to  1:0,000  pounds  of  phosplforus,  on  which  a  duty 
of  is  cents  a  pound  is  paid.  The  price  in  the  New  York  market 
ranges,  according  to  quality,  from   !.">  to  7()  cents  a  pound. 
USES. 
Phosphorus  is  used  chiefly  for  making  matches,  which  were  first 
manufactured  on  a  commercial  scale  in  1833.  Parlor  matches  were 
invented  in  1848  and  safety  matches  in  1855.  The  white  phos- 
phorus is  used  for  ordinary  matches  and  the  red  amorphous  form  for 
safety  matches.  On  account  of  the  injury  to  health  in  making  and 
handling  the  ordinary  phosphorus  and  the  danger  from  fire  in  using 
