Complex sentence: To preserve the family fortune, Josiah left his considerable fortune in trust, the income from it to be paid to Luther for life, and after Luther's death the capital to be divided equally among Luther's children.
Split into simpler sentences: To preserve the family fortune, Josiah left his considerable fortune in trust, the income from it to be paid to Luther for life. After Luther's death, the capital is to be divided equally among Luther's children.