This was a short story by Isaac Asimov, written in 1948. It is not a short story at all, as it takes the form of a chemistry paper. It is in fact a spoof, based on the idea that the more hydrophilic (i.e., water-loving) a chemical is, the faster it will dissolve in water. So, chemicals with increasing hydrophilism would decrease the time it would take to dissolve. Asimov's spoof pretends that a chemical called thiotimoline exists, and the time which it takes to dissolve is so low that the chemical actually dissolves before it touches the water. This was published in Astounding Stories, a magazine which specialised in short sci-fi stories. However, many people believed that the paper was real, and fans wrote in to the magazine asking for further information on the chemical, and libraries were "stormed" by people trying to locate the papers which Asimov had made joke references to. Although the work itself was essentially fiction, the format was of non-fiction.
This is a more literal example of people judging a book by its cover...