As the number of happenings of this sort increased, or there occurred an epidemic of disease, or a flood or famine of especial virulence, the number of alleged witches correspondingly increased; and so the persecution swelled in volume, each wave of malevolence receding only to rise in larger aspect on the next occasion of its arousing. Not until the reign of Henry VIII. were there any enactments against witchcraft in England; prior to the passage of these acts, the persecution of a sorceress followed only upon an accusation of poisoning. During some parts of the Middle Ages the crime of poisoning was extensive, and certain women were adepts in making the deadly potions. To such abandoned characters resorted persons of state who desired to make away with hated rivals, or the men and women of the nobility who sought to hide or to further their intrigues by the death of someone who stood in their way. As the women who practised the arts of the poisoner were also devotees of sorcery, the crime and the superstition came to be thought of together. One reason for the detestation of witches was the subtlety they displayed in concocting poisons which slowly sapped the vitality of a person, as if by a wasting illness. In 1541, conjuring, sorcery, and witchcraft were placed in the list of capital offences. Similar statutes were enacted during the succeeding reigns of Elizabeth and James I. The curious matter of demoniacal possession called forth a great many books and pamphlets treating of its nature, history, methods of repression, and the dispossession of those under witches' spells. John Wier, a physician, wrote a treatise, in the last half of the sixteenth century, in which he described witches as but exaggerated types of the perversity which is found in women generally. In the easy subjection of the sex to malign influences he saw a proof of its greater moral weakness.