The chief work of Trévisan is _La Philosophie Naturelle des Métaux_. He insists on the necessity of strong and discreet meditation in all students of Hermetic philosophy. Their operations must wait on nature, and not nature on their arbitrary processes. Mercury is said to be the water of metals, “in which, by a mutual alteration, it assumes in a convertible manner their mutations.” Gold is simply quicksilver coagulated by the power of sulphur. The secret of dissolution is the whole mystery of the art, and it is to be accomplished not by means of fire, as some have supposed, but, with the help of mercury, in an abstruse manner, which is not really indicated by the adept. The work of nature is assisted by alchemy, which mingles ripe gold with quicksilver, the gold comprising in itself a well-digested sulphur, by which it matures the mercury to the “anatide proportion” of gold, subtilising the elements and wonderfully abbreviating the natural process for producing the precious metal of the mines. JOHN FONTAINE. The life of this artist is buried in the obscurity of his closet or laboratory, where he divided his time between attention to his furnaces and the composition of curious verses. He was alive at Valenciennes in the year 1413. His Hermetic poem, _Aux Amoureux de Science_, has been printed several times. The author announces that he is an adept, and describes in an allegorical manner, after the fashion of the “Romance of the Rose,” and in the same quaint and beautiful tongue, the different processes which enter into the art of transmutation. His little work may be profitably studied by the neophytes of practical alchemy, though its benefits are of a negative kind, but its paradise of dainty devices and its old world nature pictures are better suited to the poet and the poetic interpretation of symbols. THOMAS NORTON. The scientific methods of Ripley were followed by this alchemist, who was born in the city of Bristol. He wrote anonymously, but the initial syllables in the six first lines, and the first line in the seventh chapter of his “Ordinall of Alchemy,” compose the following couplet:-- “Thomas Norton of Briseto, A parfet master you may him trow.”