Black Smoke

The black smoke, or black powder is a fictional poisonous gas in H. G. Wells' science fiction novel The War of the Worlds. It was used by the Martians to eliminate groups of humans remotely, especially artillery crews, before they could fire. The rockets from which they explode are fired from a "black tube" attached to the Tripod. Any human breathing this deadly smoke is killed almost instantly. The smoke would form a scum on contact with water. After the smoke had done its job, the Martians would dispel it with jets of steam, leaving only a residual black powder. The smoke is more of an ink-like vapour than a smoke, and is very dense; it can be avoided by climbing to higher places. The aliens may have used this also to avoid unnecessary destruction of buildings in cities such as London. As they used it on London after one of their Tripods is brought down by a Twelve-pounder, it may be seen as a reserve weapon in case the humans prove dangerous. Although Wells never exactly explains how the black smoke works, he does mention that it may bind with argon and cause a disastrous chemical reaction inside a human who comes in contact with it. Although as at that time argon was considered inert this is unlikely.

Wells specified that the black smoke consists of an unknown element that shows four blue lines in a spectrum analysis. This element combined with the argon in our atmosphere to form the deadly gas. (Although in the very last chapter, spectrum analysis "unmistakenly" pointed to "the presence of an unknown element with a brilliant group of three lines in the green.")

There is no such possible unknown element, and argon cannot combine with anything else, with the marginal exception of fluorine, but chemical weapons proved to be widely used in human warfare after Wells' novel was written, especially in World War I.