Am  FJe°burx8P7h6arm  }  Development  of  the  Chemical  Arts.  81 
consumption  of  gas  being  3*234  cubic  feet  (=o-i  cubic  metre),  the  light  was  equal 
to  that  of  5-22  normal  candles,  and,  though  the  lamps  at  Narbonne  were  placed  at 
intervals  of  50  metres,  Verver  pronounced  the  lighting  of  the  streets  as  perfect. 
Latterly,  since  the  preparation  of  hydrogen  has  been  improved  by  Tessie  du 
Motay  and  Marechal,  new  attempts  have  been  made  in  Paris  to  light  up  large 
squares  and  streets  with  "  platinum  gas."  Spectators,  however,  may  find  justifica- 
tion for  the  caricatures  in  the  Parisian  comic  journals  of  that  time,  which  represent 
the  passengers  in  the  streets,  and  even  infants  in  arms,  and  the  very  dogs  in  the 
gutters,  equipped  with  eye-shades  to  preserve  their  sight. 
Technical  literature  has  the  peculiarity  that  it  records  the  introduction  of  novel- 
ties, but  leaves  us  in  the  dark  concerning  their  practical  verification.  It  keeps  a 
tolerably  exact  register  of  the  births  of  inventions,  but  gives  a  very  imperfect  account 
of  their  career  in  life  and  of  their  deaths.  Thus,  with  a  single  exception,  we  are 
left  in  the  dark  as  to  the  permanent  results  of  lighting  with  hydrogen. 
The  experiments  made  with  water-gas  at  the  town  Elizabeth,  in  New  Jersey, 
yielded  unsatisfactory  results,  as  made  known  in  1865*  Great  depreciation  of 
plant,  heavy  working  expenses,  and  disproportionate  consumption  of  fuel  were  the 
causes  of  failure. 
It  was,  therefore,  the  more  desirable  to  ascertain  in  how  far  the  process  had  proved 
successful  in  Europe,  and,  thanks  to  the  kindness  of  several  correspondents,  we  have 
succeeded  in  obtaining  information.  The  fate  of  the  method  in  Belgium  appears 
from  an  extract  from  a  letter  which  M.  L.  de  Koninck,  Professor  of  Chemistry  at 
the  University  of  Liege,  kindly  forwarded  to  the  present  writer : 
The  systlme  Leprince,  which  consists  in  the  introduction  of  small  quantities  of 
water  into  the  retorts  in  which  coal  is  distilled,  had  for  a  short  time  a  certain  success 
[une  certaine  vogue),  depending  mainly  on  numerous  reclamations  by  which  it  was 
helped  out.  Its  chief  advantage  was  supposed  to  lie  in  the  fact  that  it  drove  the  gas 
out  of  the  retort,  a  purpose  for  which  an  exhauster  or  aspirator  is  now  preferred. 
The  system  has  never  been  employed  for  public  purposes  in  Belgium,  but  merely  in 
certain  manufactories.  Since  the  death  of  the  inventor,  which  took  place  some 
years  ago,  it  is  no  longer  spoken  of,  and  has  been  generally,  if  not  universally, 
abandoned.    This  has  been  the  case  at  Vieille-Montagne. 
In  a  letter  dated  March  18,  1874,  M  Landolt,  Professor  of  Chemistry  at  the 
Polytechnic  School  of  Aachen,  confirms  these  statements.  The  use  of  water-gas  is 
continued  only  in  CockeriU's  works  at  Seraing.  At  Simoni's  cloth-works  at  Ver- 
viers,  the  process  never  advanced  beyond  the  stage  of  unsatisfactory  experiments, 
although  certain  technological  papers  have  asserted  to  the  contrary.  In  Maestricht, 
where  the  water-gas  was  used  for  some  time  for  public  purposes,  it  has,  as  Professor 
Landolt  has  been  informed,  failed  to  give  lasting  satisfaction,  and  has  been  replaced 
by  coal  gas  two  years  ago  (1872).  Direct  inquiries  addressed  to  the  municipal 
authorities  have  remained  unanswered. 
The  above  statement  of  the  introduction  of  the  Drummond  light  in  English  mili- 
tary establishments  led  to  an  inquiry  being  addressed  to  the  Chemist  to  the  War 
Department,  Mr.  Abel,  of  Woolwich,  from  whom  the  following  courteous  reply 
was  received,  under  date  April  20,  1874:    "As  regards  your  inquiry  concerning 
*  Wagner,  "  Jahresberichte,"  1865,  758. 
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