Some questions a platoon commander should ask himself; 354 Defensive measure against gas attacks; 356 General considerations; 356 Nature of gas attacks; 356 Gas clouds; 356 Gas projectiles; 358 Tear or lachrymatory shells; 359 Poison shells; 359 Smoke; 359 Mine and explosion gases; 359 Protection of shelters; 360 Methods of protection; 360 Shelters which should be protected; 361 Protection of weapons and equipment; 361 Small arms and S.A.A.; 362 Hand and rifle grenades; 362 Light trench mortars; 362 Action to be taken in trenches on gas alarm; 363 Action to be taken in billets and back areas; 363 Action during gas attack; 364 Protective measures; 364 Tactical measures; 364 Precautions against gas shells; 365 Action subsequent to a gas attack; 367 General; 367 Movement; 367 Clearing dugouts and other shelters; 367 Ventilation; 368 Natural; 368 By fire; 368 By fanning; 369 Cleaning arms and ammunition; 369 Treatment of shell holes; 370 Concealment from aerial observers; 370 Orders governing intrenchment problems; 372 Company organization; 384 Company headquarters; 384 Headquarters; 384 Personnel; 385 Commissioned; 385 Enlisted; 386 Equipment; 386 Trench standing orders; 386 Duties; 386 Sentries; 387 Patrols; 388 Stand to; 389 Machine guns; 389 Reliefs; 390 Guides; 391 Smoking and talking; 391 Procedure on arrival at trenches; 391 Log books; 392 Equipment; 392 Stretcher bearers; 392 Discipline; 392 Rations and cooking; 393 Sanitation; 393 Emergency dumps for companies (material); 394 Contents of dump; 394 Stores for company; 394 Stores at battalion headquarters; 394 Conclusion; 396 Bibliography; 397