Am.  Jour.  Pharm. 
April,  191 8. 
Methods  of  Gas  Warfare. 
261 
charged.  The  Germans  made  one  mistake  in  believing  that  hilly  or 
wooded  country  would  not  do.  This  was  refuted  by  the  French, 
who  made  a  successful  gas  attack  in  hilly  and  wooded  country  in 
the  Vosges,  as  admitted  in  a  captured  German  report.  If  the  coun- 
try is  flat  like  that  about  Ypres,  and  the  wind  direction  is  right, 
there  is  very  little  difficulty  about  making  an  attack,  especially  if  the 
enemy  does  not  know  anything  about  it.  The  element  of  surprise 
is  important. 
German  gas  attacks  are  made  by  two  regiments  of  Pioneers, 
with  highly  technical  officers,  including  engineers,  meteorologists, 
and  chemists.  They  brought  their  first  cylinders  into  the  line  with- 
out our  knowing  anything  about  it,  except  from  the  deserter's  re- 
port, which  was  not  believed.  The  element  of  surprise  was  greatly 
lessened  when  we  began  to  know  what  to  look  for  and  to  recognize 
the  sounds  incident  to  the  preparation  of  a  gas  attack. 
The  first  attack  was  made  with  chlorine.  If  a  gas  attack  is  to 
be  made  with  gas  clouds,  the  number  of  gases  available  is  limited. 
The  gas  must  be  easily  compressible,  easily  made  in  large  quanti- 
ties, and  should  be  considerably  heavier  than  air.  If  to  this  is  added 
the  necessity  of  its  being  very  toxic  and  of  low  chemical  reactivity, 
the  choice  is  practically  reduced  to  two  gases :  chlorine  and  phos- 
gene. Chlorine  is  to  gas  warfare  what  nitric  acid  is  to  high  explo- 
sives. Pure  chlorine  did  not  satisfy  quite  all  the  requirements,  as 
it  is  very  active  chemically  and  therefore  easily  absorbed.  Many 
men  in  the  first  attack  who  had  sufficient  presence  of  mind  saved 
themselves  by  burying  their  faces  in  the  earth,  or  by  stuffing  their 
mufflers  in  their  mouths  and  wrapping  them  around  their  faces. 
There  were  several  gas  attacks  of  almost  exactly  the  same  kind 
early  in  191 5.  There  was  no  gas  between  the  end  of  May,  191 5, 
and  December,  191 5,  and  by  that  time  adequate  protection  had  been 
provided. 
The  first  protection  was  primitive.  It  consisted  largely  of  respi- 
rators made  by  women  in  England  in  response  to  an  appeal  by 
Kitchener.  They  were  pads  of  cotton  wool  wrapped  in  muslin  and 
soaked  in  solutions  of  sodium  carbonate  and  thiosulphate ;  sometimes 
they  were  soaked  only  in  water.  A  new  type  appeared  almost 
every  week.  One  simple  type  consisted  of  a  pad  of  cotton  waste 
wrapped  up  in  muslin  together  with  a  separate  wad  of  cotton  waste. 
These  were  kept  in  boxes  in  the  trenches,  and  on  the  word  "  gas  " 
six  or  eight  men  would  make  a  dive  for  the  box,  stuff  some  waste 
