| I have been able to get a sort of visualizable flash of insight in 4 dimensions, when I had been thinking about quaternions for over a month for 8 hours a day. |
| Hurwitz published a paper on a factorisation theory for integer quaternions in 1896 and applied it to the problem of representing an integer as the sum of four squares. |
| His work in algebraic number theory led him to study the quaternions and generalisations such as Clifford algebras. |
| Shortly after Hamilton's discovery of the quaternions his personal life started to prey on his mind again. |
| It was while he was a pupil at the bar examination that he went to Dublin to hear Hamilton's lectures on quaternions. |
| Later on, in 1858, Bellavitis included the system of quaternions into his geometric calculus. |
