3 6 0 D O C U M E N T 4 2 2 J A N U A R Y 1 9 2 3 422. From Jun Ishiwara Hota, 12 January 1923 Esteemed Professor, Your stay in our country was a special pleasure for me that I shall always cherish as such a fine memory. You are probably still happily continuing your journey! I now tried the problem in the following way: I assume two six-vectors and , whose components for bodies at rest should read: If one transforms these field vectors, e.g., through Lorentz’s transformation equations: , , , , one obtains (because of the formula: ) At rest, d = e, h = b, is valid and generally one also must set for the elec. dis- placement or, resp., the mag. field strength , resp., . Furthermore, I assume as the four-element electric current , the space and time components of which read ϕμν ψμν 23) ( 31) ( 12) ( 14) ( 24) ( 34) ( ϕμν: 0, 0, 0, iex ,– iey ,– –iez ψμν: bx, by, bz, 0, 0, 0. 1 v 2 – x′1 x1 ivx4 –= x′2 x2 = x′3 x3 = 1 v2x′4 – x4 ivx1 += ϕμν′ ∂x′μ ∂xα ------------------- ∂x′ν ∂xβ -ϕαβ = ϕ′μν: 0, –ν 1 ν2 – ------------------ez, ν 1 ν2 – ------------------ey, iex ,– –iey 1 ν2 – ------------------, –ie 1 ν2 – ------------------z ψ′μν: bx, by 1 ν2 – ------------------, bz 1 ν2 – ------------------, 0, –iν 1 ν2 – ------------------bz, 1 ν2 – ------------------by.νi ε 1 μ -- - εϕμν 1 μ -- - ψμν Tμ σϕμνuν ρuν +=