Thomson described his concept, including several possible ways to drive the current. Peierls reiterated his earlier concerns, mentioning the observations by Mark Oliphant and Harrie Massey who had worked with David Bohm on isotopic separation at Berkeley. Bohm had observed greatly increased rates of diffusion well beyond what classical diffusion would suggest, today known as Bohm diffusion. If this was inherent to such designs, Peierls suggested there was no way the device would work. He then added a highly prescient statement that there may be further unknown instabilities that would ruin confinement.