The discovery of the means of preventing pain, which will occupy the greater number of the following pages, did not arise out of any of the attempts either in ancient or modern times above enumerated. It sprung directly from the practice of inhaling chemical and medicinal substances. The custom of inhaling the fumes of narcotic plants existed at the very commencement of the historic period, as appears by the following passages from Herodotus. Speaking of the people who inhabited some small islands on the river Araxes, which flows into the Caspian Sea, he says,[22] “They add that they have discovered other trees that produce fruit of a peculiar kind, which the inhabitants, when they meet together in companies, and have lit a fire, throw on the fire as they sit round in a circle; and that by inhaling the fumes of the burning fruit that has been thrown on, they become intoxicated by the odour, just as the Greeks do by wine; and that the more fruit is thrown on, the more intoxicated they become, until they rise up to dance and betake themselves to singing.” Again, when treating of the funeral ceremonies of the Scythians, he says,[23] “When they have set up three pieces of wood, leaning against each other, they extend round them woollen cloths; and having joined them together as closely as possible, they throw red-hot stones into a vessel placed in the middle of the pieces of wood and the cloths. They have a sort of hemp growing in this country very like flax, except in thickness and height; in this respect the hemp is far superior: it grows both spontaneously and from cultivation; and from it the Thracians make garments very like linen, nor would any one who is not well skilled in such matters distinguish whether they are made of flax or hemp, but a person who has never seen this hemp would think the garment was made of flax. When, therefore, the Scythians have taken some seed of this hemp, they creep under the cloths, and then put the seed on the red-hot stones; but this, being put on, smokes, and produces such a steam, that no Grecian vapour-bath would surpass it. The Scythians, transported with the vapour, shout aloud; and this serves them instead of washing, for they never bathe the body in water.” Mental illusions of all kinds have frequently been looked on as divine revelations, not only by savages, but even by nations having a considerable amount of civilization. The priestess at Delphos became intoxicated with the fumes of narcotic plants before delivering her oracular responses, and it is a curious circumstance that when America was discovered by Columbus, it was the custom of the Indians to throw tobacco on the fire during their religious ceremonies, when the piaches, or priests, who officiated, were thrown into a state of ecstatic inebriation by the smoke they inhaled.