  Boole’s mathematical publications span the 24 years from 1841 to 1864, the year he died from pneumonia. Breaking these 24 years into three segments, the first 6 years (1841–1846), the  second 8 years (1847–1854), and the last 10 years  (1855–1864), we find that his published work on  logic was entirely in the middle 8 years.