K. Kanellakis, having realized the great value of manuscripts, dealt persistently and systematically with their collection and study, as he also maintained an antiquarian shop. Thanks to his abilities to access difficult spaces, to understand illegible writings, and to copy multi-page texts with great patience, valuable elements have been preserved. In addition to what he published, he completed two handwritten books with various subjects, which are located in the F. Argenti Library, and transcribed many others in his notebooks, giving special importance to the search for rare words, names, and toponyms. He donated a large number of extremely important manuscripts, mainly codes of Mastichochoria, to the "Koraes" Library and the Metropolitan, "so that they may not be lost" and "so that they may serve as material contributing to the history of the homeland". From the originals that he carefully preserved and from his own scholarly copies, real treasures come to light for all the important events of Chios' history, for the massacres of 1822, the earthquakes of 1881, the liberation of 1912, as well as ecclesiastical, communal, administrative, educational, hospital, loan, insurance matters, and various others, such as Ottoman manuscripts and a large catalog of Chios' sailing ships. Samples of writing of significant personalities are preserved, spiritual figures of Chios become known, such as D. Mousaios, a student of Th. Kairis, and faces and events of the island's daily life come to life.
