ON THE SYNOPSIS

by the wheel and axle original: "peritrochio", the shadoof original: "tollenone". A lever-based tool used for lifting water or weights., the pancratium original: "pancratio". Here, a specialized mechanical crane or lifting machine., and so forth. All of these will benefit from, and be benefited by, a comparison with our Mechanical Phenomena, as I have already mentioned in point 2 of the preface to those phenomena.

X. Now remains Optics, which places the finishing touch original: "colophonem imponit" on this Synopsis with seven books. The first of these deals with light, shadow, colors, the structure of the eye, vision, common objects, and deceptions of sight. The second deals with Catoptrics The study of light reflection, specifically using mirrors., or mirrors, whether they be flat, spherical, cylindrical, or conical. The third deals with Dioptrics The study of light refraction through lenses. and telescopes original: "tubis Batauicis", literally "Dutch tubes", as the telescope was a recent Dutch invention.. The fourth deals with parallaxes, or differences in perspective. The fifth deals with the art of perspective. The sixth and seventh explain the nature of refraction through various demonstrations; the seventh of these concludes with remarkable findings based on physical hypotheses.

It will be helpful to have read the observation of Sanctorius Santorio Santorio (1561 to 1636) was an Italian physician who sought to apply mathematical physics to medicine. who, on page 322 of his work on the medicinal art of Galen, states that the color black is produced when light is refracted on countless surfaces. This also occurs from transparent spheres filled with liquid and illuminated, because these generate darkness and shadows from which blackness arises. He notes that light is projected to a single point from a glass flask full of water, while shadow is cast over the remaining parts.

He says he produces white from roughly forty small, empty, and perforated glass spheres. These are equal in size to cherry pits and placed in a cup full of water. When joined together and empty, they create the color white. When they are filled with water, the color becomes black. From other non-spherical bodies, he derives green, crimson, and purple. He creates other intermediate colors: pale between white and yellow, which you might call gilvus original: "giluum" or yellowish-tawny original: "κιρρὸν" (kirrhon), such as the color of aged white wine; yellow original: "ξανθὸν" (xanthon), such as is found in yellow bile; red or glowing russet, such as in the dried saffron flower; tawny, such as in brass or the back of a fox, which they call a slightly darker rauvus A yellowish-gray or "hoarse" color.; red, Phoenician, or crimson, such as in the seeds of a pomegranate and in the upper part of a rainbow. This is similar to the purple in lips, or the colors of blood, kermes, and Tyrian purple. He also identifies blue-gray or gray-green in eyes, and blue in the heavens, lapis lazuli, and sapphire. For more, consult the author himself.

The illustrious René Descartes explained the nature of colors with even greater subtlety in the eighth discourse on the Rainbow. Anyone who reads there how colors originate from the various motions of small spheres will admit it with admiration. To this, we hope a special treatise on colors will soon be added by the most subtle philosopher Honoré Fabry. I have mentioned him elsewhere; he proves by so many reasons and observations that colors are nothing other than light reflected or refracted in various ways. He argues that white is a continuous series of rays reflected from or flowing from objects, while black is...