October, ST0'}         4  Use  for  the  Rare  Metals.  513 
are  readily  attacked  by  chemical  reagents,  while  those  that  resisted 
such  reagents,  like  gold,  had  no  effect.  He  concluded  that  the  action 
upon  the  organisms  was  due  to  the  solution  of  the  metals  taking 
place  in  the  jelly. 
But  what  a  wide  field  he  has  opened ! 
Here  is  a  world  for  exploration,  with  promise  of  rich  reward.  You 
have  many  readers  of  an  investigating  turn  of  mind.  Many  of  them 
have  their  own  private  microscopes,  and  bacteria  are  to  be  found  on 
every  hand  in  abundance.  Metals  of  some  description  are  on  every 
shelf.  Who  will  be  the  first  to  discover  that  some  other  metal  than 
cadmium  is  destructive  of  the  peculiar  species  of  bacteria  so  preva- 
lent in  serious  cases  of  scarlet  fever  ;  and  then  how  many  diseases, 
with  their  peculiar  species,  there  are  in  this  wide  world  of  disease 
and  death? 
It  may  be  necessary,  in  conducting  these  experiments,  to  resort  to 
many  species  of  the  rarer  minerals,  and  to  reduce  these  species  to 
metals  and  solutions.  But  we  have  the  young  men  who  have  the 
ability,  the  skill,  the  patience  and  the  time  to  solve  the  important 
problems. 
The  question  may  arise  where  to  obtain  the  metals  or  minerals. 
Having  given  this  subject  much  special  study  during  the  past  fifteen 
or  twenty  years,  perhaps  I  can  supply  the  key  whereby  any  known 
mineral  or  metal  can  be  provided  when  wanted.  It  is  a  remarkable 
fact  that  when  a  so-called  rare  metal  is  required  for  commercial  use, 
that  somebody,  somewhere,  will,  in  a  comparatively  short  time,  be 
able  to  supply  the  article. 
Take  our  Welsbach  light,  manufactured  at  Gloucester,  N.  J. 
When  the  manufacture  was  first  attempted  in  the  United  States,  the 
officers  of  the  Welsbach  Company  sent  out  letters  in  every  direction 
for  minerals  containing  the  metals  they  wanted.  They  had  to  ex- 
periment some  time  before  they  really  made  much  headway  ;  then 
they  concentrated  on  one  or  two  minerals — one  known  as  monazite. 
Then  the  problem  :  Where  can  this  mineral  be  found  in  sufficient 
quantities  to  enable  the  company  to  supply  the  growing  demand  for 
their  manufacture  ?  At  first  they  met  with  very  moderate  success — 
perhaps  some  people  would  have  pronounced  it  failure.  But  they 
kept  on  ;  and  now  they  can  purchase  all  the  monazite  they  require, 
either  from  North  and  South  Carolina,  or  Brazil,  with  small  quanti 
ties  now  and  then  from  other  localities. 
