From 1871 he studied the polarisation of light and later he studied electrical discharge in rarefied gases. Spottiswoode published over 100 papers and several books including, in addition to the one on determinants mentioned above: The Polarisation of Light (1874), Polarised Light (1879), and A Lecture on the Electrical Discharge, its Form and Functions (1881).
Mula 1871-aral siya ng polarisation ng ilaw at mamaya siya-aral ng electrical discharge sa rarefied gases. Spottiswoode-publish na higit sa 100 mga papeles at ilang mga libro kasama ang, bukod sa ang isa sa determinants nabanggit sa itaas: Ang Polarisation of Light (1874), Polarised Light (1879), at isang panayam sa electrical discharge, ang Form at pag-andar (1881).