The principles of light and color: including among other things the harmonic laws of the universe, the etherio-atomic philosophy of force, chromo chemistry, chromo therapeutics, and the general philosophy of the fine forces, together with numerous discoveries and practical applications ..
An 1878 New York work by Edwin D. Babbitt, a self-published treatise on light, colour and speculative "etherio-atomic" force, aimed at general readers interested in chromo-therapy. Its pictures are plain black-and-white line engravings of physical phenomena: concentric wave patterns, a shadow cast by a tree, and iron-filing style magnetic field lines around a bar magnet. A designer could take from them the look of dense hatched linework and radiating field diagrams suited to scientific or occult-themed visuals.
