Meet Laurax, a not-very-bold, not-that-exciting new fragrance. According to a panel of sniffers, it’s neither appealing nor revolting. It’s “intermediately pleasant”. People almost trip over themselves to describe it in non-descript terms—“fragrant”, “chemical” and “perfumery”.

Laurax isn’t going to set the perfume world ablaze in the near future, but its scientific implications are fascinating. This bizarre scent is actually a set of completely different fragrances that all smell roughly the same. It’s the odour version of “white”.

The colour that we call white is a blend of many different wavelengths of light. Add red and blue light together, and you get magenta. Add other colours and eventually, you converge on white. The same applies to sounds: if you combine tones of different