270  Methods  of  Gas  Warfare.         {     Ap™r;  f**™ 
the  single  rubber  sheet.  The  German  mask  now  contains  no  rubber 
except  one  washer;  the  elastic  consist  of  springs  inside  a  fabric, 
and  the  mask  itself  is  of  leather.  It  hardens  and  cracks  after  being 
wet,  and  is  too  dependent  upon  being  well  fitted  to  the  face  when 
made. 
(The  lecturer  exhibited  various  types  of  gas  shells,  helmets, 
masks,  and  respirators.) 
The  following  compounds  have  been  used  by  the  Germans  in  gas 
clouds  or  in  shells  : 
1.  Allyl-iso-thiocyanate  (Allyl  mustard  oil),  C3H5NCS  (shell). 
2.  Benzyl  bromide,  C6H5CH2Br  (shell). 
3.  Bromo-acetone,  CH2Br-CO-CH3  (hand  grenades). 
4.  Bromated  methyl-ethyl-ketone  (bromo-ketone),  CH2Br- 
COC2H5  or  CH3-CO-CHBr-CH3  (shell).  Dibromo-ketone,  CH3- 
COCHBr-CH.Br  (shell). 
5.  Bromine,  Br2  (hand  grenades). 
6.  Chloro-acetone,  CH2C1-C0CH3  (hand  grenades). 
7.  Chlorine,  Cl2  (cloud). 
8.  Chloromethyl-chloroformate  (Palite),  ClCOOCH2Cl  (shell). 
9.  Nitro-trichloro-methane  (chloropicrin  or  nitrochloroform), 
CC13N02  (shell). 
10.  Chlorosulphonic  acid,  S03-H-C1  (hand  grenades  and  "smoke 
pots  "). 
11.  Dichloro-diethylsulphide  (mustard  gas),  (CH2C1CH2)2S 
(shell). 
12.  Dimethyl  sulphate,  (CH3)2S04  (hand  grenades). 
13.  Diphenyl-chloro-arsine,  (C6H5)2AsCl  (shell). 
14.  Dichloromethyl  ether,  (CH2C1)20  (shell). 
15.  Methyl-chlorosulphonate,  CH3C1S03  (hand  grenades). 
16.  Phenyl-carbylamine  chloride,  C6H5NCC12  (shell). 
17.  Phosgene  (carbonyl  chloride),  C0C12  (cloud  and  shell). 
18.  Sulphur  trioxide,  S03  (hand  grenades  and  shell). 
19.  Trichloromethyl-chloro formate  (diphosgene,  superpalite), 
ClCOOCCl3  (shell). 
20.  Xylyl  bromide  (tolyl  bromide),  CH3C6H4CH2Br  (shell). 
