Or take the still more fascinating case of the young lady who is known in the literature of psychotherapy as Miss Beauchamp. Her story is told in a book, "The Dissociation of a Personality," by Dr. Morton Prince of Boston. Some thirty years ago Miss Beauchamp, a very conscientious and dignified young lady, became nervous and ill, and took to doing strange things, which were a source of shame and humiliation to her. Under hypnotism it was discovered to be a case of multiple personality. The other personality, who finally gave herself the name of Sally, was entirely different in character from Miss Beauchamp, being mischievous, vain, and primitive as a child. She conceived an intense dislike for Miss Beauchamp, whom she called by abusive names; at times when she could get possession of Miss Beauchamp's body, she delighted in playing humiliating tricks upon her enemy, spending her money, running her into debt, breaking her engagements, disgracing her before her friends. Sally was always well and Miss Beauchamp was always ill, and Sally would take the body, for which they fought for possession, and take it for long and exhausting walks, and leave it cold and miserable, lost and penniless, in the possession of Miss Beauchamp! And of course this made Miss Beauchamp more and more a wreck, and Sally took possession of more and more of her time. Sally knew everything that Miss Beauchamp did and thought, but Miss Beauchamp did not know about Sally. She only knew that there were gaps in her life, during which she did things she could not explain. And because she did not want her friends to think her insane, she would try to hide this dreadful condition of affairs; but Sally would spoil her plans by writing letters to her friends, and also by writing insulting letters for Miss Beauchamp to find when she took possession again.