Dramatic demonstrations of 19th-century scientific principles drew large crowds to Pittsburgh's Philo Hall for several nights during March 1842.

Two "Mesmerists" named Burleigh and Ewing relied on "animal magnetism" to place an unidentified woman into a hypnotic trance. She also served as the subject for multiple tests to prove the accuracy of phrenology.

"All the experiments were conducted in a fair, candid manner, and at their conclusion the audience expressed their gratification by a round of applause," The Pittsburgh Morning Chronicle said on March 21, 1842. The newspaper story did not include first names for either man.

"Mesmerism" was named for Franz Anton Mesmer, the German physician who developed its principles. Mesmer believed that a healthy person maintained a free flow of mysterious fluids throughout his or her body. Obstacles to the flow caused illnesses.

Mesmer first used magnets to clear pathways for the fluids. He later relied on "animal magnetism" flowing through his hands to achieve cures.

The Chronicle story does not provide details on how Burleigh placed his subject in a trance, only that the process took about 10 minutes.

"After the committee [chosen from the audience] had satisfied themselves that her eyes were closed, beyond the possibility of her seeing, a piece of steel was held near her head," according to the newspaper. "It gave her great pain, causing her to start convulsively."

The Mesmerists went on to demonstrate experiments in "sympathy," a kind of perceptual telepathy. "Various articles were handed to the operator by the committee, for the purpose of tasting them. In every instance her lips moved in correspondence with his, and either the article itself or its predominating taste, was named by her in every instance, with one or two exceptions."

One committee member tried to throw her off.

"[H]e gave the operator a piece of tobacco to taste, and when he saw the lips of the subject move, asked her how she likes cloves."

" 'I taste no cloves,' was her prompt reply. 'What do you taste then?' he asked. She immediately answered 'tobacco.' "

The program then moved on to a demonstration of phrenology. The idea behind phrenology was that different parts of the brain regulated different sensations, emotions and motor skills.

Phrenologists, however, took their idea several steps farther, dividing the brain into dozens of tiny areas of control and believing that personality, intelligence and aptitude could be read in the bumps and fissures of the skull.

As Burleigh and Ewing "magnetized" portions of their subject's brain -- each area corresponding to a different "phrenological organ," -- she described her responses to the crowd.

"The experiments ... were strikingly successful," according to the Chronicle. "Any one in the audience was permitted to hand up in writing the name of the organ he wished to have magnetized."

The "operator complied with the request without touching the organ, but simply by passing his finger near it."

"This done, he would ask 'what are you thinking of?' and her answers in every case were satisfactory."

"For example, Benevolence was magnetized. She said she was thinking of doing good -- wanted to do good to everybody, even her enemies ... Acquisitiveness -- she wanted money and when asked how much, said a hundred dollars, in addition to which she wanted as many houses as would fill a square in the city ..."

"Time and Tune -- she commenced beating time with her fingers and said she was thinking of singing. Alimentiveness -- she said she was hungry, and wanted pies, custards and roast meats ..."

Spectators at the demonstrations could be assured of good views of the proceedings in Philo Hall. "[W]e are happy to be enabled to add that the platform has been raised several feet and other arrangements made, calculated to give satisfaction to the audience," the Chronicle reported.

Philo Hall -- its full name was the Hall of the Philological Institute -- was located on what is now Fourth Avenue, east of Market Street. In the early 1840s, the building served multiple purposes in bustling Pittsburgh, also housing the mayor's office and the Board of Trade reading room. The original structure was destroyed in the Great Fire of 1845, but it was rebuilt nearby.