Sunday 23rd September 1917: School children across the county of Bedfordshire are being asked to help the war effort by collecting horse-chestnuts. A considerable amount of grain is being used in the production of essential war supplies and experiments have shown that conkers would be a suitable substitute. It is hoped that for every ton of horse-chestnuts harvested, half a ton of grain can be saved for human consumption. Schools have been asked to form small committees to organise the collection. The nuts must be fully ripe, and should be removed from the outer green husk before they are deposited at the collecting station.
Source: Leighton Buzzard Observer 25th September 1917
 The reason for collecting conkers was kept secret at the time, but it was hoped they could be used to create acetone needed in the manufacture of cordite for munitions. The process of making acetone from starch-based foodstuffs, which made the large-scale production of cordite possible, was developed in 1915 by Chaim Weizmann, who later became the first President of Israel.