How a unit of battery voltage got its name

This from http://home.teleport.com/~n3eg/hamhumor.htm

Little credit in the field of battery research is given to the humble assistant of the famed inventor Alessandro Volta. It is a scarcely known fact that while Volta was partaking in a midday drink, an assistant by the name of Thaddeus Purcell would plunder the waste bins, removing all his discharged batteries and hiding them in his pockets. Upon arriving at his home, Mr. Purcell would connect the batteries in series and proceed to create large sparks, which he utilized to light his pipe. In his honor, a unit of battery voltage was named after him, which is the unit comprised of total battery voltage divided by the number of cells he had pilfered that day, or Volts Purcell.