Although Calleja took every possible precaution before his departure from San Luis Potosí to insure the preservation of that province, his efforts were unavailing. When Hidalgo at the opening of his career passed through Celaya, he was joined by Luis de Herrera, a lay friar of the order of San Juan de Dios of the province of Mexico. For some time this man followed the army in the capacity of chief surgeon; but being compelled to go to San Luis on private business, he was arrested as a suspicious person, and imprisoned in the jail, it not being known that he was a friar. Heavily fettered and with no prospect of release, he disclosed himself in order to escape from durance, and was removed to the Carmelite convent, in which Calleja had imprisoned suspected persons. Erelong Herrera prevailed on the comandante, Cortina, to allow him to retire to the convent of his order in San Luis, the prior and other conventuals becoming his sureties. Having thus secured comparative freedom, he conceived, in conjunction with Juan Villarias, a lay brother of the same convent, the daring scheme of getting possession of the city during a single night. With this intent they instigated Joaquin Sevilla y Olmedo, an officer of the San Cárlos lancers, to place at their disposal a few troops, and some arms which he had in his house. Sevilla entered into their designs, and on the night of the 10th of November, meeting a patrol of his own corps and another of the cavalry, he called on them to assist him in the execution of an order of the commander. With this small force he proceeded to the convent of San Juan de Dios, where he was joined by the two friars. The revolutionists then went to the Carmelite convent, and ringing the night-bell,[1] requested that a priest might be sent with them to confess a prominent citizen who was dying. The door-keeper opened the gate,
- ↑ In every convent was a door-bell called the campana de misericordia, which was rung by those who, during the night, sought the assistance of confessors for persons dangerously ill.
