Complex sentence: He had been using subcutaneous injections of creosote for tuberculosis and in 1894 administered subcutaneous injection of chaulmoogra oil in a 36-year-old Egyptian Copt who had been unable to tolerate oral treatment.
Split into simpler sentences: He had been using subcutaneous injections of creosote for tuberculosis. In 1894 he administered subcutaneous injection of chaulmoogra oil to a 36-year-old Egyptian Copt who had been unable to tolerate oral treatment.