In the British Museum; (4) the fragment called Quinta Pars Compendii Theologiae, in the British Museum; (5) the Compendium Studii Theologiae, in the British Museum; (6) the logical fragments, such as the Summulae Dialectices, in the Bodleian, and the glosses upon Aristotle's physics and metaphysics in the library at Amiens.
This quinta essentia had been speculated upon by the Greeks, some regarding it as immaterial or aethereal, andothers as material; and a school of philosophers termed alchemists arose who attempted the isolation of this essence.
We Su have seen that the science took its origin in the arts practised by the Egyptians, and, having come under the influence of philosophers, it chose for its purpose the isolation of the quinta essentia, and subsequently the " art of making gold and silver."
16 54" (1655); "Tractatus duo, prior de cycloide, posterior de cissoide et de curvarum turn linearum dthivvec turn superficierum RrXarva,uw" (1659); "Mechanica, sive de motu tractatus geometricus" (three parts, 1669-1670-1671); "De algebra tractatus historicus et practicus, ejusdem originem et progressus varios ostendens" (English, 1685); "De combinationibus alternationibus et partibus aliquotis tractatus" (English, 1685) "De sectionibus angularibus tractatus" (English, 1685); "De angulo contactus et semicirculi tractatus" (1656); "Ejusdem tractatus defensio" (1685); "De postulato quinto, et quinta definitione, lib.
In some books, especially the poetical, the columns were increased to eight by the addition of the Quinta and Sexta, but the Octapla, as the enlarged work was called, was not apparently a distinct work.