“I being an adept, anonymous, and lover of learning, decreed to write this little Treatise of physical secrets in the year 1645, in the twenty-third year of my age, to pay my duty to the sons of art, and lend my hand to bring them out of the labyrinth of error, to show the adepts that I am a brother equal to them. I presage that many will be enlightened by these my labours. They are no fables, but real experiments, which I have seen, made, and know, as any adept will understand. I have often in writing laid aside my pen, because I was willing to have concealed the truth under the mask of envy; but God compelled me to write, Whom I could not resist: He alone knows the heart--to Him only be glory for ever. I undoubtedly believe that many will become blessed in this last age of the world with this arcanum. May the will of God be done! I confess myself unworthy of effecting such things--I adore the holy will of God, to Whom all things are subjected! He created and preserves them to this end.” A simple arithmetical operation will show that the author was consequently born in the year 1621, when also Eugenius Philalethes, otherwise Thomas Vaughan, first saw the light. This would remain unchallenged, but for the fact that the original edition[AH] of the _Introitus_ is asserted to read _trigesimo anno_, in the thirty-third year, instead of _vigesimo anno_. There is no copy of this original edition in the British Museum, and my knowledge of it is derived from the reprint in Langlet du Fresnoy’s _Histoire de la Philosophie Hermétique_. Eirenæus, in accordance with the later impressions, is venerated by the faithful of Hermes as the adept who accomplished the grand and sublime act at the age of twenty-two. These grounds, which in themselves are considerable, may be supplemented by the fact that there is much similarity in the style and methods of the two writers. Eugenius Philalethes wrote _Anthroposophia Theomagica_; _Anima Magica Abscondita_, published together in 1650; _Magia Adamica_, 1650; “The Man-Mouse” (a satire on Henry More, the Platonist); “The Second Wash, or The Moore (_i.e._, Henry More) Scoured once more,” 1651; _Lumen de Lumine_, 1651; “The Fame and Confession of the Fraternity R.C.,” 1652; _Aula Lucis_, 1652; “Euphrates, or The Waters of the East,” 1655. “A Brief Natural History,” published in 1669, also bears his name, and in 1679 his poetical remains were published by Henry, his brother, along with some effusions of his own, entitled _Thalia Rediviva_. Some idea of the confusion which exists in the minds of biographers and bibliographers alike on this point may be gathered from the fact that some authorities represent Thomas Vaughan as dying in 1656, while Chalmers’ Biographical Dictionary attributes all the works of Eugenius Philalethes to Henry the Silurist, whom he terms a Rosicrucian fanatic.