Complex sentence: Watson is met by Stamford, his fellow-student at Bart's, who takes him to meet Sherlock Holmes, who is beating corpses with a cane to establish the principle of bruising after death.
Split into simpler sentences: Watson is met by Stamford, his fellow-student at Bart's, who takes him to meet Sherlock Holmes. Sherlock is beating corpses with a cane to establish the principle of bruising after death.