Paracelsus, as well as his predecessors, laboured studiously to discover some method for prolonging life. Like Bacon and Verulam, he maintained that the human body could be rejuvenated to a certain extent by a fresh supply of vitality, and it was his aim to find means by which such a supply could be obtained. In one of his works he gives the following reasons for this belief: “Metals may be preserved from rust and wood may be protected against rot. Blood may be preserved a long time if the air is excluded. Egyptian mummies have kept their form for centuries without undergoing putrefaction. Animals awaken from their winter sleep, and flies having become torpid from cold become nimble again when they are warmed. Therefore, if inanimate objects can be kept from destruction, why should there be no possibility to preserve the life-essence of animate forms?” For this purpose he prepared a remedy he called _Primum Ens Melissæ_, which was made by dissolving pure carbonate of potass, and macerating in the liquid the fresh leaves of the _melissa_ plant. On this absolute alcohol was poured several times in successive portions to absorb the colouring matter, after which it was collected, distilled, and evaporated to the thickness of a syrup. The second great secret elixir of Paracelsus was his _Primum Ens Sanguinis_. This was prepared by mixing blood from the medium vein of a healthy young person, and digesting it in a warm place with twice its quantity of _alcahest_, after which the red fluid was to be separated from the sediment, filtered, and preserved. The alcahest was his celebrated universal medicine, and was considered the greatest mystery of all. It was made with freshly prepared caustic lime and absolute alcohol. These were distilled together ten times. The residue left in the retort was mixed with pure carbonate of potass and dried. This was again distilled with alcohol. It was then placed in a dish and set on fire, and the residue that remained was the alcahest. The following lines were found inscribed on the fly-leaf of an old work on alchemy, printed in 1550, and signed “PHILO VERITAS”:— ELIXIR VITÆ. When fire and water, earth and air In love’s true bond united are, For all diseases then be sure You have a safe and certain cure. I will affirm it’s here alone Exists the Philosophic Stone. This is fair nature’s virgin root, Thrice blest are they who reap the fruit: But oh! where one true adept’s found, Ten thousand thousand cheats abound. In an ancient work in the library of York Minster, the writer came across the following in manuscript, signed “RAYMUND LULLI”:—