King's large body of poetic and prose works survives in both printed and manuscript form. The majority of his poetry was published posthumously in the 1637 anthology of Scottish Latin
Delitiae Poetarum Scotorum. Contained in this collection are several significant and substantial pedagogical poems on astronomy and
cosmology, which deal directly with new scientific and philosophical concepts such as hypotheses on multiple universes and
heliocentrism. (see selected poetry below). A manuscript containing the poetry that was not published is stored in the library of the University of Edinburgh. It is bound with a larger manuscript that contains King's most important work: a large prose commentary on the poem
De Sphaera by
George Buchanan. The commentary is a comprehensive account of ancient, medieval, and early-modern cosmology and natural philosophy. In a letter to William King (Adam King's nephew, see above), Jacobean poet and bibliophile
William Drummond of Hawthornden stated that King's edition of the
Sphaera was the most outstanding work of his 'excellent' corpus, written by 'the most learned man' that Scotland had produced. The survival of classroom student notes and published student disputations show that this sentiment was shared by the university community in general: the commentary was used for instruction in cosmology, astronomy, and natural philosophy at the
University of Edinburgh from the early 17th century until at least 1650. A letter, calendar, and catechism all written by King in
Scots survive. Like King's Latin poetry from Paris, they date from the late 16th century, and reveal his sympathy for the
Counter-Reformation in
Scotland and Europe in that period. ==Later life and death==