Griffithes Wheeler Thatcher, 1911 Encyclopædia Britannica, Volume 15… (1911)
“ His writings—like those of other Arabian philosophers—are encyclopaedic and are concerned with most of the sciences; they are said to have numbered over two hundred, but fewer than twenty are extant. Some of these were known in the middle ages, for Kindī is placed by Roger Bacon in the first rank after Ptolemy as a writer on optics. ”
