7. Formulæ connected with small continuous Displacements of the Particles of a Medium

Extract

Although most of the results deduced in this Note have been long known, I venture to offer it to the Society on account of the extreme simplicity of the analysis employed, and the consequent insight it affords us into the connection of various formulæ. I intend on a future occasion to give large further developments especially bearing on physics. I employ the calculus of quaternions throughout, but where some unusual expressions occur, I have given them in their common Cartesian form, as well as in the quaternion one.