The Philosophy of Natural Magic, by Henry Cornelius Agrippa, L. W. de Laurence ed. , at sacred-texts.com
This advertisement appeared at the end of the original 1913 edition of this book. It is included for completeness.—JBH.
For many ages people have sought some medium, instrument, or means by which they might penetrate through, or lift the veil which hangs between the world we inhabit and that vast spiritual realm where causes reside and principles exist. To that end, recourse has been had to various so-called marvelous methods;
To all who have failed so far there is a surer, better and safer way, and that is self-development, by means entirely within the reach of every one, and which are within their will and control; and which require but the elements of Time, Patience and constant practice to ensure very good results; if not complete success in soul-sight.
The best way is for the student to use some form of the spirit-glass or Magic Mirror.
Full particulars regarding the construction, magnetizing and use of the Magic Mirror is contained in "A Message to All Mystics," also read article concerning Soul Sight and Magic Mirrors, which will be found in our Great Catalogue. All those desiring special instructions on various points regarding the making, use and care of the Magic Mirror should read the above articles by Dr. de Laurence very closely, then there will be no need for further inquiry.
If you wish to own a real, genuine Opaque Magic Mirror and be able to make it exactly as it was made by famous ancient
[paragraph continues] Mystics so that it will possess Occult Virtue and become infused with Astral Auras, then proceed as hereinafter instructed.
Foremost, procure unto thyself the following materials from de Laurence, Scott & Co., with which to make your own Opaque Magic Mirror:
One Convexo-Concave superior transparent glass which has a perfect and complete sphericity of form on the properly indicated side; manufactured by a certain secret process and formed by infusing silicious matter with fixed alkalies; but so constructed that it possesses none of the qualities of the lens, so that rays of Astral Light passing through it are not made to change their direction or to magnify or diminish objects at a certain distance, as does the crystalline humour of the human eye.
In other words, this exclusive Convexo-Concave superior transparent glass must be made by a special process that it has no mitigating, assuasive or lenitive qualities whatsoever.
Its exact size must be 5 12-16 × 7 12-16 inches.
Next obtain a sufficient amount of a secret bituminiferous substance like that used by the ancient mystics and old philosophers for this very purpose.
Also one small brush; very fine.
Messrs. de Laurence, Scott & Co. will, upon order, supply the materials hereinbefore mentioned, consisting of one specially made Convexo-Concave superior transparent glass, 5 12-16x7 12-16 inches, a sufficient amount of a secret bituminiferous substance to give the glass three coats and make it Opaque; also a brush to apply the substance on the glass.
Order No. 135—The above materials will be sent in a mailing case, securely packed, together with "THE FAMOUS MESSAGES TO ALL MYSTICS," which gives full directions for making a Magic Mirror. Price, $2.50. Foreign, 12s, 10d.
Same material as described above, except that the superior transparent glass is XX heavy, and the more desirable, especially for professional business.
Order No. 136—Price with one fine Sable Brush and a sufficient amount of bituminiferous substance to make same perfectly opaque, $3.50, prepaid. Foreign, 16s 5d.