9. Using Invisible Ink and Corpse Gas
French physician Séverin Icard was not content to merely rest on his laurels after the scandal of his questionable heart flag test. In a test more fitting for the pages of a spy novel, Icard devised a system in which he wrote “I am really dead” on a piece of paper in invisible ink made of acetate of lead. He would then place this paper by the deceased’s nose. One of the gases produced by the decomposition process is sulfur dioxide. When acetate of lead is exposed to sulfur dioxide, it causes the acetate to discolor and become visible on the page. While this was certainly a dramatic way to “prove” death, it is unfortunately extremely unreliable.
First, sulfur dioxide can be exhaled by living humans with some dental diseases or tonsillitis. Second, not all corpses reliably produce sulfur dioxide in quantity near the nose to trip Icard’s test. An English doctor attempted to recreate Icard’s method and found that only one out of every six corpses triggered the “I am really dead” message. So, sadly, the most fashionable and cinematic method of determining death was a bust. However, one must genuinely applaud Séverin Icard’s determination to develop weird and new ways to certify death.