Am.  Jour.  Pharm. 
April,  191 S. 
Methods  of  Gas  Warfare. 
269 
to  keep  it  on.  The  sneezing  gas  has,  however,  not  been  a  very  great 
success. 
All  bombardments  now  are  of  this  mixed  character.  The  shells 
used  are  marked  with  differently  colored  crosses,  and  definite  pro- 
grams are  laid  down  for  the  use  of  the  artillerymen. 
As  regards  the  future  of  gas  shells,  it  should  be  emphasized  that 
the  "gas  shell"  is  not  necessarily  a  gas  shell  at  all,  but  a  liquid  or 
solid  shell,  and  it  opens  up  the  whole  sphere  of  organic  chemistry 
to  be  drawn  upon  for  materials.  The  material  placed  inside  the 
shell  is  transformed  into  vapor  or  fine  droplets  by  the  explosion  and 
a  proper  adjustment  between  the  bursting  charge  and  the  poisonous 
substance  is  necessary.  Both  sides  are  busy  trying  to  find  some- 
thing that  the  others  have  not  used,  and  both  are  trying  to  find  a 
"  colorless,  odorless,  and  invisible  "  gas  that  is  highly  poisonous.  It 
is  within  the  realm  of  possibilities  that  the  war  will  be  finished,  lit- 
erally, in  the  chemical  laboratory. 
The  Germans  have  not  altered  their  type  of  respirator  for  some 
time,  and  it  is  not  now  equal  in  efficiency  to  the  British  or  American 
respirator.  The  German  respirator,  even  in  its  latest  form,  will 
break  down  at  a  concentration  of  0.3  per  cent,  of  certain  substances. 
The  German  design  has  given  more  weight  to  military  exigency,  as 
against  perfect  protection,  than  has  the  British.  Another  thing  that 
weighs  against  changes  in  design  is  the  fact  that  the  German, 
already  handicapped  by  the  lack  of  certain  materials,  must  manu- 
facture 40,000,000  respirators  a  year  in  order  to  supply  his  Aus- 
trian, Bulgarian,  and  Turkish  allies,  as  well  as  his  own  army. 
In  the  British  and  American  armies  the  respirator  must  always 
be  carried  with  the  equipment  when  within  twelve  miles  of  the  front. 
Between  twelve  and  five  miles  a  man  may  remove  the  respirator 
box  in  order  to  sleep,  but  within  five  miles  he  must  wear  it  con- 
stantly. Within  two  miles  it  must  be  worn  constantly  in  the  "alert" 
position  (slung  and  tied  in  front).  When  the  alarm  is  given  he 
must  get  the  respirator  on  within  six  seconds.  The  American  respi- 
rator is  identical  with  the  British.  The  French  have  a  fabric  mask 
made  in  several  layers,  the  inner  provided  with  a  nickel  salt  to  stop 
HCN,  then  a  layer  with  hexamethylenetetramine ;  it  has  no  valve 
and  is  hot  to  wear.  The  French  also  use  a  box  respirator,  consist- 
ing of  a  metal  box  slung  on  the  back,  with  a  tube  connecting  to  the 
face  mask;  the  latter  is  of  good  Para  rubber  and  is  provided  with 
a  valve.    One  disadvantage  of  this  form  is  the  danger  of  tearing 
