THE  MAGNESIAN  LIGHT. 
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THE  MAGNESIAN  LIGHT. 
Photographers  are  indebted  to  the  perseverance  of  M.  Son- 
stadt  for  the  removal  of  a  great  obstacle.  Every  one  knows 
the  difficulty  which  has  hitherto  been  experienced  in  getting  a 
powerfully  actinic  artificial  light.  Such  a  light  is,  however, 
furnished  by  the  combustion  of  the  metal  magnesium,  and, 
thanks  to  M.  Sonstadt,  this  metal  is  now  procurable  at  a  price 
which  makes  it  available  for  practical  purposes. 
Magnesium  is  an  easily-inflammable  metal.  A  wire  of  con- 
siderable thickness  can  be  ignited  in  the  flame  of  a  candle,  and 
the  light  evolved  by  the  combustion  is  of  great  intensity.  It 
has  been  ascertained  that  a  wire  of  0-297  millimetre  diameter 
will  give  as  much  light  as  twenty-four  stearine  candles  of  five 
to  the  pound.  The  powerfully  actinic  character  of  the  light 
has  been  recently  demonstrated  by  Mr.  Brothers,  of  Manches- 
ter, and  Mr.  Sydney  Smith,  both  of  whom  have  produced  good 
pictures  by  its  use. 
The  metal  is  neither  ductile  nor  very  malleable.  It  cannot 
be  drawn,  but  by  employing  a  method  devised  by  Dr.  Matthi- 
esen,  it  can  be  forced  in  a  softened  state  through  a  small  open- 
ing in  an  iron  cylinder,  and  thus  strands  of  wire  of  considera- 
ble length  can  be  formed.  The  wire  has  been  found  to  burn 
more  steadily  when  three  or  four  strands  are  twisted  into  a 
rope  ;  and  a  simple  clockwork  arrangement  will  deliver  such  a 
rope  to  a  spirit  or  oil  lamp,  in  the  flame  of  which  it  may  be 
burned. 
We  look  for  important  results  from  the  use  of  this  light. 
The  opportunities  for  its  use  are  numerous ;  and  we  may  expect 
our  collections  to  be  soon  enriched  with  pictures  of  objects 
hitherto  shut  out  from  photographers. 
Some  are  talking  wildly  of  "  night  pictures,"  as  though  they 
expected,  by  means  of  magnetism,  to  obtain  a  picture  of  the 
gloomy  effects  of  midnight  on  a  scene.  The  principal  use  of 
the  light  will,  of  course,  be  for  dark  interiors ;  and  we  hope 
soon  to  see  the  magnificent  grottoes  of  Adelsburg  and  Antipa- 
ros — which  the  pencil  is  as  powerless  to  draw  as  the  unaided 
camera  to  depict — revealed  as  brightly  as  the  caverns  in  the 
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