The idea mentioned above, that the grosser elements of man's nature might be refined away and immortality attained, seems to have suggested an immortality, not merely in an unseen world, but even in this one, to be secured by an imaginary elixir of life. Certain at any rate it is, that so far back as a century or so before the Christian era, the desire to discover this elixir had become a national craze. The following story is historical, and dates from about 200 B.C.:— "A certain person having forwarded some elixir of immortality to the Prince of Ching, it was received as usual by the doorkeeper. 'Is this to be swallowed?' enquired the Chief Warden of the palace. 'It is,' replied the doorkeeper. Thereupon, the Chief Warden purloined and swallowed it. At this, the Prince was exceedingly angry and ordered his immediate execution; but the Chief Warden sent a friend to plead for him, saying, 'Your Highness's servant asked the doorkeeper if the drug was to be swallowed, and as he replied in the affirmative, your servant accordingly swallowed it. The blame rests entirely with the doorkeeper. Besides, if the elixir of life is presented to your Highness, and because your servant swallows it, your Highness slays him, that elixir is clearly the elixir of death; and for your Highness thus to put to death an innocent official is simply for your Highness to be made the sport of men.' The Prince spared his life." The later Taoist was not content with attempts to compound an elixir. He invented a whole series of physical exercises, consisting mostly of positions, or postures, in which it was necessary to sit or stand, sometimes for an hour or so at a time, in the hope of prolonging life. Such absurdities as swallowing the saliva three times in every two hours were also held to be conducive to long life. There is perhaps more to be said for a system of deep breathing, especially of morning air, which was added on the strength of the following passage in Chuang Tzŭ:— "The pure men of old slept without dreams, and waked without anxiety. They ate without discrimination, breathing deep breaths. For pure men draw breath from their uttermost depths; the vulgar only from their throats." A Chinese official with whom I became acquainted in the island of Formosa was outwardly a Confucianist, but inwardly a Taoist of the deepest dye. He used to practise the above exercises and deep breathing in his spare moments, and strongly urged me to try them. Apparently they were no safeguard against malarial fever, of which he died about a year or so afterward. Associated closely with the elixir of immortality is the practice of alchemy, which beyond all doubt was an importation from Greece by way of Bactria.