Attending Planck's lectures did not take up all her time, and Meitner approached Heinrich Rubens, the head of the experimental physics institute, about doing some research. Rubens said that he would be happy for her to work in his laboratory. He also added that Otto Hahn at the chemistry institute was looking for a physicist to collaborate with. A few minutes later she was introduced to Hahn. He had studied radioactive substances under William Ramsay and Ernest Rutherford, and was already credited with the discovery of what were then thought to be several new radioactive elements. Hahn was the same age as Meitner, and she noted his informal and approachable manner. In Montreal, Hahn had become accustomed to collaboration with physicists—including at least one woman, Harriet Brooks.