Historic derivation of Wien's law Every book I've read, including a lot of websites, Wikipedia, etc, say that Wien derived this:
$$\rho_\nu(T)=\rho(\nu,T)=\nu^3f\left(\frac{\nu}{T}\right)$$
Being $\rho_v(T)$ the spectral enegy density of a black body for a given temperature and electromagnetic wave frequency. And everywhere it's mentioned that he proved this using thermodynamical arguments in a paper from 1893. I haven't been able to find that paper or that thermodynamical argument, which is what I'm interested in. I've been looking for a few days already.
Does anybody know how he did this?
 A: Link to original version (German)
Willy Wien: Über die Energievertheilung im Emissionsspectrum eines schwarzen Körpers. Annalen der Physik, Band 294, Nr. 8, S. 662–669 (1896)
http://myweb.rz.uni-augsburg.de/~eckern/adp/history/historic-papers/1896_294_662-669.pdf
Today's derivation


*

*We calculate the eigenmodes of a box, where the mode index is $j^2 = j_x^2+j_y^2+j_z^2=\left(\frac{2\nu}{c}L\right)^2$ where we used the condition of resonance.  

*We calculate the number of modes $G(\nu)=2\frac{1}{8}\frac{4\pi}{3}j^3$ in the frequency spectrum between 0 and \nu. 

*We calculate the spectral mode density $g(\nu)=\frac{\partial G(\nu)}{\partial\nu}$. The spectral energy density $u(\nu)$ is now the product of $g(\nu)$ and the energy per mode $\epsilon_{Wien}=h\nu e^{-\frac{h\nu}{k_B T}}$ (from classical Boltzmann statistics) per volume $L^3$. 

*The rest (simple math) is up to you or check the German reference 1. You get the relation from above and $$u(\nu)=\rho(\nu)e^{-\frac{h\nu}{k_B T}}\;.$$
