An essential complement to the chemist's job, in an annexed room presently closed to the public in general, different types of balances are found: Romans, precision, torque and even some small manual scales of the 18th century, almost all in a perfect working condition. This room also contains the so-called "metro de litigios de Bilbao" or "meter of Bilbao", which served the city council of Bilbao in settling disputes arising between merchants, clients and neighbors.