His colleagues in the librarianship were Alexander of Aetolia and Lycophron of Chalcis, to whom were allotted the tragic and comic writers respectively, Homer and other epic poets being assigned to Zenodotus.
His Tagebuch, Berlin, 1865), retired from the librarianship in 1854, and in 1861 from his professorship, but continued to reside at Bonn until his death.
Wished to appoint him canon of Windsor, but the prime minister, Lord Liverpool, objected; Sumner received instead a royal chaplaincy and librarianship, and other preferments quickly followed, till in 1826 he was consecrated bishop of Llandaff and in 1827 bishop of Winchester.
As Duke Albert sided with Osiander, Chemnitz resigned the librarianship. Returning (1553) to Wittenberg, he lectured on Melanchthon's Loci Communes, his lectures forming the basis of his own Loci Theologici (published posthumously, 1591), which constitute probably the best exposition of Lutheran theology as formulated and modified by Melanchthon.
In the following year he received, in spite of the usual accusations of heresy, the librarianship of the Advocates' Library in Edinburgh, small in emoluments (40 a year) but rich in opportunity for literary work.