268  Methods  of  Gas  Warfare.         {Am April'  ?g*£m' 
It  may  thus  be  possible  to  neutralize  a  part  of  the  infantry  by  cut- 
ting down  their  supplies  and  ammunition. 
The  use  of  a  gas  shell  to  force  a  man  to  put  on  his  mask  is  prac- 
tically neutralization.  If  at  the  same  time  you  can  hurt  him,  so 
much  the  better.  Hence  the  change  in  gas-shell  tactics,  which  con- 
sists in  replacing  the  purely  lachrymatory  substance  by  one  that  is 
also  poisonous. 
One  substance  used  for  this  method  of  simultaneously  harassing 
and  seriously  injuring  was  dichloro-diethysulphide  (mustard  gas). 
Its  use  was  begun  in  July  of  last  year  at  Ypres,  and  it  was  largely 
used  again  at  Nieuport  and  Armentieres.  A  heavy  bombardment 
of  mustard-gas  shells  of  all  calibers  was  put  on  these  towns,  as  many 
as  50,000  shells  being  fired  in  one  night.  The  effects  of  mustard 
gas  are  those  of  a  "  super-lachrymator."  It  has  a  distinctive  smell, 
rather  like  garlic  than  mustard.  It  has  no  immediate  effect  on  the 
eyes,  beyond  a  slight  irritation.  After  several  hours  the  eyes  begin 
to  swell  and  inflame  and  practically  blister,  causing  intense  pain,  the 
nose  discharges  freely,  and  severe  coughing  and  even  vomiting 
ensue.  Direct  contact  with  the  spray  causes  severe  blistering  of 
the  skin,  and  the  concentrated  vapor  penetrates  through  the  clothing. 
The  respirators  of  course  do  not  protect  against  this  blistering. 
The  cases  that  went  to  the  hospitals,  however,  were  generally  eye 
or  lung  cases,  and  blistering  alone  took  back  very  few  men.  Many 
casualties  were  caused  by  the  habit  that  some  of  the  men  had  fallen 
into  of  letting  the  upper  part  of  the  mask  hang  down  so  as  not  to 
interfere  with  seeing.  The  Germans  scored  heavily  in  the  use  of 
this  gas  at  first.  It  was  another  example  of  the  element  of  surprise 
in  using  a  new  substance  that  produces  new  and  unusual  symptoms 
in  the  victims. 
Up  to  the  present  time  there  has  been  no  material'  brought  out 
on  either  side  that  can  be  depended  on  to  go  through  the  other  fel- 
low's respirator.  The  casualties  are  due  to  surprise  or  to  lack  of 
training  in  the  use  of  masks.  The  mask  must  be  put  on  and  ad- 
justed within  six  seconds,  which  requires  a  considerable  amount  of 
preliminary  training,  if  it  is  to  be  done  under  field  conditions. 
Among  other  surprises  on  the  part  of  the  Germans  were  phenyl- 
carbylamine  chloride,  a  lachrymator,  and  diphenylchloroarsine,  or 
"  sneezing  gas."  The  latter  is  mixed  in  with  high  explosive  shells  or 
with  other  gas  shells,  or  with  shrapnel.  It  was  intended  to  make  a 
man  sneeze  so  badly  that  when  he  puts  on  his  mask  he  is  not  able 
