At the same time that Brown was campaigning against alternating current a New York state bill replacing hanging with electrocution was signed into law (June 4, 1888) and set to go into effect on January 1, 1889. A Buffalo, New York dentist named Alfred P. Southwick had been developing a method using a device similar to a dental chair, an execution device referred to as the electric chair. The law did not specify the type of current to use, or the means, so the New York Medico-Legal Society, an informal society composed of doctors and lawyers, was given the task of working out the details. Committee head Frederick Peterson, a neurologist who had assisted in the dog electrocutions at Columbia College, enlisted Brown's services as a consultant. Brown set up an experiment at Edison's West Orange laboratory on December 5, 1888 with members of the press, members of the Medico-Legal Society, the chairman of the death penalty commission, and Thomas Edison looking on. Brown used alternating current for all of his tests on animals larger than a human, including 4 calves and a lame horse, all dispatched with 750 volts of AC. Based on these results the Medico-Legal Society recommended the use of 1000-1500 volts of alternating current for executions and newspapers noted the AC used was half the voltage used in the power lines over the streets of American cities.