Complex sentence: He highlighted certain peculiarities of the Arabic language, which he claimed could not be found in any other language and challenged his adversaries, to refute his claim also addressing Max Muller (1823-1900) to come forward and meet the challenge.
Split into simpler sentences: He highlighted certain peculiarities of the Arabic language, which he claimed could not be found in any other language. He challenged all his opponents, to refute his claim and also addressed Max Muller (1823-1900) to come forward and meet the challenge.