Blackmailing is another practice that springs from the conduct of both men and women influenced in the direction of vice and crime by sex impulses; and jealousy is a powerful factor in the causation of some crimes of violence. Jealousy is not generally looked for on the part of those who are themselves loose in their conduct, but among them it may exist as intensely and manifest itself as powerfully as in any respectable citizen. It seems to be largely a matter of temperament, and to be to some extent existent apart from the desire for exclusive possession. X 25 was an ex-soldier married to a woman of low morals. They had both been loose in their behaviour and were both given to drink. He had on several occasions assaulted her for her infidelities, but he admitted that it was not jealousy that had caused him to do so; and he owned that he was just as bad himself. He went off to the war, and in his absence she behaved very badly and took headlong to drink. She lived with another man. On his return he took up house with her, and the other man was a source of quarrel between them, especially when they were drinking. He was admittedly jealous, though there does not seem to have been any but a retrospective cause for the feeling. One day in the course of a quarrel she compared him with the other man to his disadvantage, and he savagely set on and killed her. X 26 was a sailor who was attached to a woman whom he knew to be a prostitute. When he came to Glasgow he lived with her, quite well knowing her character. He spent his money freely on her, but could not keep her from her associates. One night she insisted on leaving the house where they lodged. She had been drinking heavily, and he tried to detain her. She insisted on going to the lodgings of another man whom he knew; and when he endeavoured to persuade her to remain where she was, she made a comparison between him and the other that set him in a blind fury of rage and jealousy, in which he killed her. The cases present similar features: a tolerance of general infidelity; a jealousy of a particular individual; and an explosion when the other was praised for certain qualities.