WATCH: A Closer Look at a WWI Gas Hood

NICK: So we have a variety of objects here, could you just take us through them and explain what they are? ANDREW: Well I mean, we might as well start with the most dramatic one, which is this object here. People say it's a gas mask - it's not, it's a gas hood. When Germany decided to use mustard gas, chlorine gas, just, a most dreadful weapon to use against the opposition. The problem with mustard gas is, it's entirely wind dependent. So the British High Command were convinced Germany wouldn't use gas because it's so unpredictable. You can lob gas shells over, but if the wind changes, that's coming straight back at you. They came up with these, and people look at this and think, oh, well they breathed in through there - you didn't, you actually breathed in through the cloth. This was saturated with chemicals, ostensibly to neutralize the effect of the mustard gas - it didn't - and this was just chucked inside your blouse, your battle dress jacket. Um, glass eyepieces. It's very rare to find one of these in such good condition because all the cloth was impregnated with chemicals. They would rot around the eyepieces and around the mouthpieces and eventually just disintegrate. But this was stabilized quite soon after the Great War, which is how we have it in the collection today. But imagine being in a trench and seeing soldiers wearing these, advancing towards you - pretty terrifying.