Complex sentence: Georg Hartung also met and receive correspondencies and scientic materials with Charles Darwin and with Sir Charles Lyell, the pioneer of modenr geology, he visited the Canary Islands in the winter of 1853 and the spring of 1854.
Split into simpler sentences: Georg Hartung also met and corresponded with Charles Darwin and with Sir Charles Lyell, the pioneer of modern geology, from whom he received scientic samples. He visited the Canary Islands in the winter of 1853 and the spring of 1854.