100 and 50 years ago.

Featured here are reprints of articles and letters to the editor of the magazine "Nature" previously published by different scientists. "Chalk gas" seems unnecessary, even as a temporary name for carbon dioxide, commented researcher Arthur Smithsell in 1904. To call carbon dioxide "chalk-stuff gas" asserts that it comes from chalk, or that in other words, it is a kind of air fixed somehow in chalk. In connection with some recent legal proceedings, a new method for detecting fingerprints has been discovered, an article published in March 1954 says. The method involves the well-known ninhydrin test for amino acids, often used in chromatography. In this method, fingerprints on paper have always been considered a great nuisance, and one is often recommended to use forceps to avoid fingerprints.