Dissertatio physico-mathematica, phaenomena luminis: viribus attractivis [et] repulsivis corporum subjacere [et] ex his derivari posse, statuens; cujus partem tertiam, consentiente ampliss. ordine philosoph. In Imperiali Academia Aboënsi, praeside mag. Joh. Fredr. Ahlstedt, mathem. professore, publ. [et] ordin. Pro gradu, publice ventilandam sistit Henricus Widenius, stipend. publ. Borealis, in auditorio philos. die 19 Maji 1819. H. a. m. solitis