London lit by dead herrings? Brilliant!

An idiosyncrasy peculiar to the herring is that, when dead, it begins to glow; this property, which resembles phosphorescence and is yet altogether different, peaks a few days after death and then ebbs away as the fish decays. For a long time no one could account for this glowing of the lifeless herring, and indeed I believe that it still remains unexplained. Around 1870, when projects for the total illumination of our cities were everywhere afoot, two English scientists with the apt names of Herrington and Lightbown investigated the unusual phenomenon in the hope that the luminous substance exuded by dead herrings would lead to a formula for an organic source of light that had the capacity to regenerate itself.