The Act Against Multipliers, 1404

The Act Against Multipliers was signed into law by King Henry IV of England on 13th January 1404. It ordered that “None from hereafter shall use to multiply gold or silver, or use the craft of multiplication; and if any the same do, they incur the pain of felony”. 

This had nothing to do with mathematics but everything to do with alchemy, which was the forerunner of modern chemistry. The idea of alchemy was that it was possible to turn base metals into precious ones, particularly gold. We know today that this is impossible, except possibly during massive stellar explosions, but that was not the case in 1404, when many people labored long and hard to achieve this aim. 

The Act was not passed out of a desire to stop people wasting their time on something that could never work, but from fear that it actually might do so. The last thing a medieval king wanted was somebody getting very rich and not only upsetting the economic order but becoming more powerful than the monarch. 

In practice, the law provided a loophole for would-be alchemists in that they could apply for a very expensive licence that allowed them to pursue their dark art. However, it has to be assumed that not many such licences were applied for. 

The Act was eventually repealed in 1689, partly due to the lobbying efforts of Robert Boyle, the father of modern chemistry. Surprising as it might seem, he was also a keen alchemist!

© John Welford