"And then the Aryans -- if we may believe that good man Bramachari Bawa -- knew a branch of science (Viman Vidya) about which the West is now speculating much, but has learnt next to nothing. They could navigate the air, and not only navigate but fight battles in it, like so many war eagles combating for the dominion of the clouds. To be perfect in aeronautics, as he [Bramachari Bawa] justly says, they must have known all the arts and sciences related to that science, including the strata and currents of the atmosphere, their relative temperature, humidity and density, and the specific gravity of the various gases. At the Mayasabha, described in the Bharata, he tells us, were microscopes, telescopes, clocks, watches, mechanical singing birds, and articulating and speaking animals. The Ashta Vidya -- a science of which our modern professors have not even an inkling -- enabled it's proficients completely to destroy an invading army by enveloping it in an atmosphere of poisonous gases...." -- Henry S. Olcott, theosophist, India Past Present and Future, 1880
LiveScience: Buried Soldiers May Be Victims of Ancient Chemical Weapon.
Almost 2,000 years ago, 19 Roman soldiers rushed into a cramped underground tunnel, prepared to defend the Roman-held Syrian city of Dura-Europos from an army of Persians digging to undermine the city's mudbrick walls. But instead of Persian soldiers, the Romans met with a wall of noxious black smoke that turned to acid in their lungs. Their crystal-pommeled swords were no match for this weapon; the Romans choked and died in moments, many with their last pay of coins still slung in purses on their belts.
Nearby, a Persian soldier — perhaps the one who started the toxic underground fire — suffered his own death throes, grasping desperately at his chain mail shirt as he choked.
These 20 men, who died in A.D. 256, may be the first victims of chemical warfare to leave any archeological evidence of their passing, according to a new investigation. The case is a cold one, with little physical evidence left behind beyond drawings and archaeological excavation notes from the 1930s. But a new analysis of those materials published in January in the American Journal of Archaeology finds that the soldiers likely did not die by the sword as the original excavator believed. Instead, they were gassed.