Complex sentence: Michel Laurin, one of the foremost advocates of phylogenetic nomenclature, considers that the concept of a chemical element has been stable ever since Dmitri Mendeleev put forth the periodic table in 1869.
Split into simpler sentences: Michel Laurin, one of the foremost advocates of phylogenetic nomenclature, uses the history of chemistry as an example. He considers that the concept of a chemical element has been stable ever since Dmitri Mendeleev put forth the periodic table in 1869.