Images from Johann Zahn’s Oculus Artificialis (1685)

In 1685, the Würzburg cleric Johann Zahn published his Oculus Artificialis Teledioptricus Sive Telescopium (The Long-Distance Artificial Eye, or Telescope). In the work he provides an early and comprehensive account of the function and usage of a number of optical instruments, including the camera obscura and magic lantern (whose invention he credits to Athanasius Kircher), and various other lanterns, slides, peepshow boxes, telescopes, microscopes, lenses, and reflectors. Among the studies is an envisaging, for the very first time, of a portable hand-held version of the camera obscura. At the heart of the imagined device is a mirror reflex mechanism, technology that would not see realisation until a century and a half later with the birth of the photographic camera. Zahn’s ideas and explanations are furnished by a plethora of innovative, and, at times, wonderfully surreal engravings, highlights of which we feature below.

The Surreal Art of Alchemical Diagrams

Derived from the Arabic root “kimia”, from the Coptic “khem” (referring to the fertile black soil of the Nile delta), the word “alchemy” alludes to the dark mystery of the primordial or First Matter (the Khem). The discovery of this elusive original matter, from which all others are deemed simply polluted variants (the purist being Gold), is considered the alchemist’s central goal — along with the discovery of the Stone of Knowledge (The Philosophers’ Stone) and the key to Eternal Youth. As you can imagine, not the simplest of day jobs. As well as reams of text, the ins and outs of the alchemist’s task, steeped as it is in a dizzyingly complex symbology, has given birth to a whole host of strange and wondrous imagery over the centuries. Here we pick out some favourites, many found on Wellcome Images and the brilliant Manly Palmer Hall collection at the Internet Archive.

The Basic Alchemy