Conkers at war

Conkers are the seeds of the horse chestnut Aesculus hippocastanum tree. They are, of course, essential to the ancient sport of conker fighting much enjoyed by little boys and by big boys who, like me, have never really grown up. During the First World War they played an important role in much bloodier battles.

Propellants were needed to fire the high explosive artillery shells. The standard propellant used by the British Army and Royal Navy was cordite. The manufacture of cordite needed nitroglycerine (much of which was made from whale oil), guncotton, nitric acid, petroleum jelly and the solvent acetone. For much of the war the supply of acetone was a major problem and led to shortages of shells. The crisis was eventually resolved when Chaim Weizmann discovered the bacterium Bacillus clostridium acetobutylicum which could ferment starch into acetone and butyl alcohol.

Initially maize, rice and wheat were used as sources of starch for the fermentation, but these were also needed to feed the populace. Large quantities were shipped from the United States but by 1917 German submarines were severely limiting imports. Weizmann started to look for non-edible supplies of starch and soon discovered that conkers could be used.

The Ministry of Munitions endorsed the idea and encouraged children to contribute to the war effort by collecting conkers. In the event, children collected far more conkers than could be transported to the fermentation factory! You can see them at work here!

Much of this information has come from Michael Freeman’s new book The Chemists’ War 1914-1918.