William Gladstone, when chancellor of the exchequer in the 1850s, is said to have asked Michael Faraday, the great scientist, whether a new discovery called electricity would ever have practical value. Faraday replied: “Why, sir, there is every possibility that you will soon be able to tax it!”

Scientific discovery improves life and creates wealth like nothing else. But that notion has essentially been on trial in the US for decades. According to the National Science Foundation, federal spending for research and development grew at just 1.3 per cent annually from 1989 to 2009, while gross domestic product rose 2.4 per cent. That is bad news – but may be about to get worse.

The US is poised to allow across-the-board cuts to federally funded research from Friday, as part of the automatic budget cutting known as sequestration. This would be a big mistake. It would further weaken the most powerful stimulant of economic growth ever devised.