8  2  Development  of  the  Chemical  Arts.  { Am' fc^1"' 
the  introduction  of  the  lime-light  in  military  premises,  I  have  to  communicate  that 
at  the  period  you  mention,  experiments  were  made  for  a  short  time  in  two  of  our 
establishments,  but  that  the  question  of  its  formal  introduction  has  never  been 
seriously  entertained." 
The  illumination  of  the  galvano-plastic  works  of  Christofle  with  water-gas  was 
likewise  of  brief  duration,  and  the  process  has  been  long  ago  abandoned.  We  are 
indebted  to  this  firm  for  the  following  communication  under  date  April  21,  1874: 
"In  reply  to  your  letter  of  the  17th,  we  have  to  state  that  the  use  of  hydrogen  in 
our  works  came  to  an  end  in  1853  on  account  of  certain  difficulties. {inconevmietiti) 
which  presented  themselves,  and  that  we  have  no  longer  preserved  the  documents- 
bearing  upon  the  matter." 
It  only  remained  to  ascertain  the  fate  of  the  so-called  platinum  gas  at  Narbonne. 
To  do  this  with  certainty,  there  appeared  no  other  method  than  to  appeal  to  the 
courtesy  of  the  municipal  authorities.  The  Mayor  of  Narbonne  had  the  kindness 
to  comply  fully  with  our  request,  and  to  sign  the  following  instructive  and  character- 
istic letter,  dated  March  16:  "The  relations  of  Prussia  and  France  since  the  war 
impose  upon  me  the  greatest  caution  as  regards  inquiries.  As  the  question,  how- 
ever, is  one  of  a  purely  scientific  nature,  I  have  handed  over  your  letter  to  the  Abbe 
Prax,  chemist  to  the  Agricultural  Society  of  Narbonne,  who  has  for  a  long  time 
occupied  himself  with  the  subject.  I  have  the  honor  to  enclose  a  copy  of  the 
memoir  which  he  placed  in  my  hands." 
Account  of  the  Water-gas  in  Narbonne  from  1855  to  1865. 
"In  May,  1855,  I  was  sent  to  Paris  by  the  municipality  to  test  the  water-gas  of 
Passy.  My  report  was  dated  June  8,  1855.  The  town  adopted  this  method  of 
lighting  and  heating,  and  came  to  an  agreement  with  the  company  called  the  1  Nar- 
bonnaise/ 
"From  1856  the  Passy  system  was  in  use  in  Narbonne.  We  modified  the  burners 
in  several  respects,  as  those  of  Passy  were  not  sufficiently  lasting.  The  high  tempera- 
ture of  the  retorts  occasioned  from  time  to  time  the  loss  of  a  furnace,  and  after 
many  losses  the  system  of  retorts  was  abandoned  in  favor  of  another  apparatus,  the 
'  Cubilot'  (Faye's  apparatus).  Towards  the  end  of  1858  it  was  heated  with  wood 
charcoal,  which  soon  gave  place  to  coke  on  account  of  its  costliness.  At  the  same 
time  we  made  important  changes  in  the  burners  and  platinum  baskets,  the  latter  of 
which  were  suspended  instead  of  resting  upon  the  former. 
"  The  illumination  with  hydrogen  is  brilliant  but  sensitive  [delicat).  The  lamps 
in  the  streets  must  be  well  closed,  as  a  gust  of  wind  distorts  the  ignited  platinum 
wick.  The  dust  introduces  sand,  which  forms  a  silicide  of  platinum,  and  this  metal 
ultimately  assumes  an  injurious  crystalline  structure,  and  is  even  partially  volatilized. 
"In  Narbonne  all  care  was  wanting  towards  the  end  of  the  career  of  the  com- 
pany Narbonnaise.  The  manager,  M.  Crouzet,  became  a  wine  merchant  in  Paris. 
All  superintendence  was  withheld,  and  the  lighting  became  at  last  intolerable.  In 
June,  1865,  therefore,  coal  gas  was  introduced.  As  far  as  heating  is  concerned, 
nothing  can,  in  my  opinion,  compete  with  water-gas  in  convenience  and  cheapness." 
Prax,  Chemist  to  the  Agricultural  Society. 
Narbonne,  March  15,  1874. 
On  the  evidence  of  these  documents,  the  procedures  for  illumination  with  hy- 
