Faraday Paper

Michael Faraday was a scientist in 19th century whose experiments with chlorine and ammonia led to the invention/discovery of refrigeration. He conducted an experiment with Chlorine Hydrate, which entailed putting it into a sealed glass tube in the shape of a "v" with one end in a hot water bath and the other end in an ice bath. This allowed him to collect chlorine gas, as well as liquefied chlorine in the glass chamber. According to NOVA: Absolute Zero, Faraday was unexpectedly interrupted while performing this experiment. This person asked Faraday what he was doing and observed a yellow, oily residue in the tube while Faraday was explaining the experiment. Faraday decided to break open the glass tube to see if the residue could be collected, which led to glass projectiles flying towards his face (or as Faraday put it "the parts flew asunder as if with an explosion"). The yellow residue was no longer present in the tube, which led to his discovery that chlorine gas was being released out of the broken tube. This led to further experimentation with similar procedure so that he could attempt to identify the compounds in the tube, which he later did using the specific gravity of chlorine.

Information used: http://www.chemteam.info/Chem-History/Faraday-Chlorine-1823.html