Unless the world should finish to-morrow, no one can have the pretension to suppose that our contemporaries have said the last word of science, and nothing will remain for our descendants to discover, no errors for them to correct, no theories for them to set straight." [Illustration: FIG.VI._See p.

90._] [Illustration: FIG.VII._See p.

90._] [Illustration: FIG.VIII._See p.

91._] What kind of experimental evidence could an alchemist furnish in support of his theory of transmutation?
In answering this question, I cannot do better than give a condensed rendering of certain pages in Hoefer's _Histoire de la Chimie_.
The reader is supposed to be present at experiments conducted in the laboratory of a Grand Master of the Sacred Art in the 5th or 6th century.
_Experiment_ .-- Ordinary water is boiled in an open vessel; the water is changed to a vapour which disappears, and a white powdery earth remains in the vessel.
_Conclusion_ .-- Water is changed into air and earth.
Did we not know that ordinary water holds certain substances in solution, and that boiling water acts on the vessel wherein it is boiled, we should have no objection to urge against this conclusion.
It only remained to transmute fire that the transmutation of the four elements might be completed.
_Experiment._--A piece of red-hot iron is placed in a bell-jar, filled with water, held over a basin containing water; the volume of the water decreases, and the air in the bell-jar takes fire when a lighted taper is brought into it.
_Conclusion._--Water is changed into fire.
That interpretation was perfectly reasonable at a time when the fact was unknown that water is composed of two gaseous substances; that one of these (oxygen) is absorbed by the iron, and the other (hydrogen) collects in the bell-jar, and ignites when brought into contact with a flame.
_Experiment_ .-- Lead, or any other metal except gold or silver, is calcined in the air; the metal loses its characteristic properties, and is changed into a powdery substance, a kind of cinder or calx.
When this cinder, which was said to be the result of the _death of the metal_, is heated in a crucible with some grains of wheat, one sees the metal revive, and resume its original form and properties.
_Conclusion._--The metal which had been destroyed is revivified by the grains of wheat and the action of fire.
Is this not to perform the miracle of the resurrection?
No objection can he raised to this interpretation, as long as we are ignorant of the phenomena of oxidation, and the reduction of oxides by means of carbon, or organic substances rich in carbon, such as sugar, flour, seeds, etc.

Grains of wheat were the symbol of life, and, by extension, of the resurrection and eternal life.
[Illustration: FIG.IX._See p.