Two early lattice theory papers
The early history of lattice theory is studied in Herbert Mehrtens,
Die Entstehung der Verbandstheorie (Gerstenberg Verlag, Hildeshelm, 1979).
We would do well to read Mehrtens and some of the early papers on our
subject. In the meantime, for your enjoyment, here are a translations
of a couple.
The first is a couple sections of Dedekind's Supplement XI to Dirichlet's
Vorlesung uber Zahlentheorie, where he introduces the modular law,
studied at greater length in the classic paper of 1900.
The second is a section from Skolem's 1920 paper that contains a solution
to the word problem for finitely presented lattices. (Thanks to Stan Burris
for finding out about this!) See our chapter on finitely presented lattices
in Lattice Theory: STA for a modern treatment.