Einstein announces four papers to his friend.

The first paper “deals with radiation and the energetic properties of light” – the paper on the light-quantum hypothesis.

“The second paper is a determination of true atomic size from diffusion and internal friction.” This is Einstein’s dissertation.

“The third proves that, under the requirements of molecular theory, the heat in bodies suspended in fluids [...] must execute a perceptible, random movement” – his work on Brownian Motion.

“The fourth [...] is an electrodynamics of moved bodies applying a modification of the theory of space and time.” In this work Einstein formulates his Special Theory of Relativity.