Professor Cohen to Speak at 4.30 o'Clock

Professor Ernst Cohen of the University of Utrecht will speak at the Chemical Colloquium in Boylston 9 this afternoon at 4.30 o'clock. The subject of his address will be "The Diffusion Problem". All members of the University are invited.

The lecture by Dr. N. F. Hall, G. '15, on the atomic theory and the structure of inorganic compounds, which was scheduled for this afternoon, has been postponed to November 30.